It's funny how circumstances pile up to produce outcomes that would never be anticipated. A dose of the dreaded lurgy before Christmas, and subsequent working from home for more than the usual number of days in the working week caused a few days' time-off to accrue and an unexpected holiday in the new year. You can guess that I spent time on the bus instead of wasting away at home, and a number of little steps were taken in the right direction. One of the broken drill bits was extracted easily with thin-nosed pliers because I could grasp the web of the bit and it wasn't stuck fast. Application of the diamond drill for a rather long time and with great care enabled whatever was stuck in the other hole in the cant-rail to be eroded and dislodged, so a wooden dowel was inserted along with the last few screws in the nearside rear gutter moulding. Hooray! The re-positioning of the fuel filter onto the chassis side-member has been achieved, and the run of fuel line from the stop-cock to the filter entry has been fashioned by re-purposing one of the original lines from SMS637. The steel fuel pipes from SM106 were so rusty that straightening and bending anew resulted in the pipe cracking. No surprise there! The line which runs from the filter outlet to the chassis manifold is still a 'work in progress'.

More amazing still was a day out to catch up on a meeting whose principle was established a year ago, but which never happened due to the inadequacies of the Covid-era rail timetable on the North Wales Coast, intervening holidays and general inertia. So it was a special pleasure to meet a lot of buses, and a number of people, some of whom were new acquaintances and others whom I have not met in years, but all dedicated bus restorers. I discovered that the view of the road from the cab of an RT is extraordinarily good, and was treated to a short tour of the locality before a fine lunch in a most congenial local café. We caused a bit of a stir with other customers when replenishing essential fluids at a nearby filling station, but I am sure the regular staff are well-used to such visits. I have always thought that the RT is my favourite bus, and to spend a while riding on one with a highly competent driver refreshed my determination to get SM106 on the road. Thanks to eveybody who made my visit so interesting and enjoyable.

Replenishing vital fluid. Photo © J.Wilkins

The re-located fuel filter, and pipework looking good. Holes to the right are original radiator outrigger locations Photo © J.Wilkins

The irony of spending the following day under SM106 continuing the task of the fuel-filter lines is not lost on me. Despite extensive use of nylon piping in various places, the steel pipes to and from the fuel filter and shut-off are original manufacture. I don't like nylon, which has again shown its tendency to brittleness in old age. A loop of flexible pipe was found between the fuel tank and the filter/agglomerator, but it simply snapped while being manipulated. At least my new stuff is more pliable. In order to complete the fuel pipe run, a new loop from the filter/sedimenter to the chassis union had to be made, and once it was installed I thought it might be amusing to see if I could suck fuel from my carry-can. Well, no, sadly; I could blow bubbles, but not generate enough suction to draw fuel up to the lift-pump. I was not really expecting anything else, but the fuel system is in two logical halves: suction and pressure divided by the lift-pump. How would the pressure side behave? I relocated the carry-can to the top of the engine sump and released the suction line from the manifold. Powerful fuel flow ensued with hand-priming, so the filter was bled and then came the bitter blow. My re-purposed steel fuel-pipe was leaking from a crack I had not observed. Disappointing, but at least I have the benefit of some practice, and the run from the lift-pump to the shut-off seemed fine and dandy. Now to source some new metal pipe! Following a refresher course on maintenance of the fuel and air systems courtesy of the London Transport MB/SM manual, I was reinstating pipework which has been cleaned and painted, and followed the intermediate pressure line to the gearbox. Here I drained condensate from the EP valve gallery (check) and from the chambers beneath that gearbox pistons (check), which made me feel better. The oil emulsion was prolific at the reverse piston, which surprised me, but now it is gone and the area cleaned up with a squirt of WD40. I also brushed off another pound or so of oily soil sticking to the front of the gearbox, and noticed that someone has replaced the third-gear air pipe from the EP valve unit, but left part of the old pipe in the clamp. the cheapskates! While I was down there I noticed one of the lubrication pipes to the rear spring-shackle was dangling, so I set about replacing it. Some hope! Once again I found that the compression olive that I had sourced was too small to grip the pipe by the time the pipe-nut had bottomed. You would think it was the easiest job imaginable to replace 10" of nylon pipe, but those 'b*****d brass' olives are making my life very unhappy at the moment. I remain certain that boxes of 'proper' olives are sitting on a workshop shelf somewhere, unrecognised by their owner and crying out to be used. "So it goes", as Kurt would say. At least the new metal pipe which I ordered on Friday had arrived the following Monday. Service or what?

Copper/Nickel alloy pipe is the go-to material for corrosion-free brake pipes, as used by (I am told) Rolls-Royce, Aston- Martin, Porsche and Audi for production, and by anyone who cannot work in steel for repairs. Petrol-heads are wont to use it for fuel lines, and I am betting it is good for diesel too. The joke, of course is that while it is easy to bend, straightening it is not so easy when it is delivered as a coil, which is the only credible, postable format! Anyway, after a while I had a fair copy of the steel line from shut-off valve to fuel-filter, and I was feeling quite pleased. The former for bending, you will be pleased to learn, was none other than the exhaust manifold of my spare engine! After another short while I had a loop of nylon pipe to the fuel injection-pump connection at the engine manifold. While this is adequate for testing, a re-make in metal will be an interesting task as I have no pattern to follow. I already knew that I couldn't suck fuel up from the tank (or its temporary replacement fuel-can), so the lift-pump line was dropped into the can while it stood on the sump. Vigorous priming resulted in a veritable spurt of fuel from the filter union-nut, which was a big disappointment because it showed that once again my compression fittings were not sealing. This was not what I was hoping for, but curiously, the new union at the shut-off valve was just fine. I went home in a blue funk, and pondered for a couple of weeks while other, diversionary life-stuff carried-on. During this down-time, I found that I had won a portable compressor from the laboratory at work, which was very welcome because a source of air pressure for testing would be very useful indeed.

It was obvious that I had to examine the joints at close quarters, so I was forced to remove the filter/agglomerator from the chassis with pipes attached and use soapy water in the time-honoured fashion to reveal leaks under pressure. Yes, the pipe from the tank WAS leaking, but why? Undoing the joint revealed that the compression olive was improperly seated and consequently mangled, so a new olive and length of pipe was subsituted and the joint made while holding the filter unit in the bench-vise. The result was an impressive lack of bubbles! The unit was rapidly re-installed and the joint to the chassis connector made with great care. I also tested the action of the lift-pump, and to my great joy I was rewarded with a copious supply of fuel at the shut-off valve, so things were looking-up! Then it was a case of repeating the trick with the rear fuel-filter, which was messy and unpleaant because the bowl was full of fuel. Hah! Once again it was obvious that trying to make the joints while working upside-down in the half-darkness was not conducive to success, and after a while a fresh attempt with a new olive was apparently successful. I decided to leave the fuel-line off for a while in order to render access to the radiator header-tank easier, and turned to finishing the new securing straps. It wasn't difficult, just threading the four ends at ¼" UNF for a short length for the securing nuts. After a trial fitting the tank was dismounted to go home for painting. and the end of a day of mixed, but generally positive fortune.

TfW Civity 197011 en route to Manchester Airport at Deganwy, 1047h, 9th Feb. Photo © J.Wilkins

I just took a ride on one of the new 197 DMUs for TfW, having never ridden a CAF before. They are not diagrammed for my normal commute, but run on the trips before and after my 0847h departure; similarly in the evening. Differences between Civity and Coradia are many, but my first impression was of utility, where I am used to a more relaxed ambience - and the doors in the saloon make it a noisy and unwelcoming space. I did like the big screens for journey information (Welsh first, wrth gwrs) and pointing to the side to alight. BTW, Deganwy is no longer a request stop! They also go like a whippet out of the station, and I was amazed by what appeared to be wheel-slip protection cutting-in on a fine evening. No indeed, they have a six-speed 'hydracyclic' gearbox with integral retarder. It may be computer-controlled and made by ZF but that is a delightful piece of 'old-school' traction engineering. The MTU (Rolls Royce) lump is very quiet, but there are noisy, intrusive hydraulic motors for aircon or compressor. It was no surprise that the unit was waiting for departure time at both Colwyn Bay and Llandudno Junction, after giving me a fright by arriving earlier than anticipated by my own just-in-time arrival at the barrier! More miles required for a more nuanced review.

A breakdown of equipment in the laboratory where I work had a surprising outcome recently - I 'won' a small, portable air-compressor after it was made redundant by a larger, more capacious unit. This advances the agenda for the year, which will henceforward be known as 'The Year of Air' because it is problems with air-piping that is becoming the ultimate barrier to mobility. Now that I can generate and apply pressure, it will be possible to experiment and (with luck) to make progress. The first step was to commission the manufacture of new compression olives for bits of 5/8" pipe that have been sacrificed long-since in the name of progress. My prototype application of nylon pipe for steel is the short link from the rear-brake reservoir to the main line which runs to the foot-brake valve. Lead-times are long, so I was pleased to get the job under way before I was due to go on the traditional February half-term break that my son has instituted. Tenerife relies upon swift and efficient buses and coaches to move natives and tourists alike, so it was a treat to travel around a geologist's mecca for three days on digital Green Rover tickets. The vehicle pictured is green, but this 363 is literally a long way from the erstwhile London Country 363 route serving High Wycombe and Penn. Buses are operated by TITSA, whose Ten+ smartcard offers stored value or bargain day tickets for 10 Euro. I put over 430km onto mine, and even managed a tram ride, though it was more like a funicular, so steep is the island.

Scania K360IB4 No. 2406 with Castrosua Magnus.e body. Photo © J.Wilkins

Entrance door ram, SM88. Photo © K.valla

On my return from foreign parts I made a bee-line to Dragon Hydraulics at Llandudo Junction to explain my predicament joining the compressor to my bus, and came away with a push-fit connector which screwed into the airline adapter I already had. Firing up the generator and compressor led to some disappointment because the emergency release valves were in an unknown position after the long-term removal of their handles and I was greeted by a gentle hissing sound from many places, some expected, some very much unexpected. Technically, there was success of course, because pressure was being supplied and it was just the start of a de-bugging journey. One place where air was escaping was more of a worry - the ram on the entrance doors, which emitted copious air from the end of the actuator tube. Definitely wrong, whatever the valves said! I had a chat with PSV Transport Systems, who maintain more modern Peters door gear, but their man said he had never seen anything like the one that was kindly photographed for me by Keith Valla, who happened to be at SM88 in the middle of my working week. Fortunately, his turned out to be just like mine, but not actually leaky! Enquiries are out in any area I can think of where expertise may be found on this very common part, which almost certainly only needs new O-rings. The poor performance of the compression olives on my new fuel filter were addressed by going back to Midland Chandlers and purchasing complementary 'Surefit' olives. Breaking into air-piping was addressed by finding and purchasing a new 5/16" tee-fitting from a vintage car parts company. These are unusual, as the compression nut goes inside the diameter of the fitting (like the fuel-filter nut) and thus is a more compact item. Unusual, but universal on the PRV auxiliary air circuits for the doors. I love the fact that someone still makes a fitting which is already 50 years old, and probably a deal older than that (even though they are not exactly cheap).

So, I now just had to wait for the bits, but life goes on, and I now had some idea of how the doors worked, even if the details were hazy and the release valves unknown. I sat for a whole morning puzzling over the problem at our local eye-hospital out-patients, and came up with an answer of sorts. I could see that the solenoid valves had three ports, as did the manual release valves, but I could not see anything which controlled exhaust air. Remember that I was brought up on steam locomotives, and they have inlet and exhaust ports on both sides of their pistons. However, think for a moment that the force on a piston is the product of pressure and area, and it is obvious that the side which carries the piston rod (the door actuator in our case) is smaller by virtue of the rod itself, and the force that can be exerted is smaller than that on the cylinder-head side. I surmised that the Peters door-engine has a piston with a very thick piston-rod, so the imbalance is even greater. I now know that the steam passages in a locomotive are carefully designed to overcome this imbalance, but I didn't realise it before, having only dealt with low-technology model engineering of the LBSC variety. The upshot of this is that you do not need an exhaust valve because the incoming air forces the contents out of the piston-rod side at operating pressure. Who cares about back-pressure, or efficiency in a door engine? I also twigged that air is supplied at full pressure to the piston-rod side at all times, thus simplifying the valve gear necessary to open and close the door. That also ensures that the default state of the door is 'closed'. If air is admitted to the head end of the ram assembly the door will open, and if that side is connected to exhaust the door will close. Simple! There are thus three parallel valve systems, one electrical and two manual (inside and outside the bus) which have the same function. I also realised that air pressure is supplied to the middle port of the manual valves, and was forced to disassemble one which was stuck in an unknown state. The valves are simple - either straight through or pressure is connected to one side, which corresponds to the 'emergency' open condition. Putting it back together and setting it to the 'closed' state was easy, and everything was soon bolted up.

Air-piping macaroni, SM88. Photo © K.valla

Entrance door ram ready for test. Photo © J.Wilkins

Eventually, the weekend came around and the postman dropped two little Jiffy-bags on our doormat. To cut a long story short, I was able to connect my flying air-line to the exit door circuit in isolation, and with prior knowledge and 50 psi on the gauge I was able to open and close the doors manually from inside or outside the bus. How brilliant was that! Bear in mind, of course that the doors are not yet actually mounted on the actuator poles! Then I took hold of the ram from the entrance and used the same flying air-line to apply pressure to front and rear connectors, with the correct effects, but an unsurprising sound of escaping air from the open end of the cylinder. The great thing is, I can now bench-test the rams! I also discovered that the Peters door-engine has a spring-loaded constrictor on the head-end air outlet, so that the doors are decelerated as they approach the closed position. All I need now is a repair kit and some knowledge on how to get inside! After that it was time to fit the refreshed radiator header tank, and refit the fuel line and filter with its new olive. That bit was last to allow some wiggle-room while fitting the tank, around which the fuel lines are routed closely. The Spring offensive is gathering momentum, but I still don't have a cap for the header tank!

Radiator header tank back in place. Photo © J.Wilkins

Peters entrance door ram disassembly. Photo © J.Wilkins

Spring, however, is not yet gaining much traction, and a work session was spent with a scant 3 degrees on the thermometer - even inside the garage! Staying focused and productive was a problem, but actually things went well. First was the end-cap of the door ram, where my club hammer and a special drift (actually a 2" length of scaffolding tube cut for the purpose) were used to push the cap carefully down into the bore of the cylinder in order to release the internal circlip. The big hammer was just to ensure that the drift was hit as squarely as possible, and apply a suitable force. This had not occurred to me at first, but a mechanic of long-standing who visits the garage for a chat from time to time took one look and said "there are a lot of hydraulic cylinders like that, just push it in." He was right of course! The clip came out and after a little persuasion with a broom handle, so did the cap with its O-ring seal, and the piston assembly. The first surprise exhibit was a gnarled lump of rubber, which appeared to be part of a seal onto the air inlet/exit port of the end-cap. I hadn't expected a secondary, spring-loaded piston with a seal, but I surmise it is a buffer that slows the bleed of air to exhaust when it closes imperfectly, and prevents the main piston moving to the door-closed position too violently. Everything else looked pretty reasonable, and I set about extracting the pneumatic seals. I was expecting O-rings, but these lip-type seals are standard parts for pneumatics. I am now in dialogue with a specialist company on seals to see what can be done to replace them and restore proper functioning of the ram. The rest of the day was spent working at freeing-off the nut on the air-pipe which connects the brake pressure reservoir to the relay valve. This long-term miscreant forced me to unscrew the whole pipe assembly from the tank, but of course it cannot be replaced the same way. Heat, penetrating oil and patient force was applied until eventually a small degree of movement was detected and the nut simply wiggled back and forth until eventually, with reluctance it started to rotate properly. It was soon re-inserted between the air-tank and valve, and the position of the tank adjusted so that there was a minimum of strain in the system. Then I installed the short, nylon pipe with its two bespoke compression olives that links the tank to the foot-brake valve (rear brakes), and found that there was a reassuring bite onto the pipe. The seal will be tested when I can get some air into the job. Lying on the cold floor manipulating cold metal and tools was no fun, and I was pleased to be on my way when I concluded that the day was done.

Recent progress turns out to be a reprise of some old, or very old narrative. Much of a morning was spent in bending-up a length of alloy pipe to run between the chassis manifold and the fuel filter, which is not straightforward due to the way that it twists and turns to reverse direction and also pass beneath the offside chassis member. As ever, the former which I have used for the bends is the exhaust manifold of my spare engine, which is conveniently massive and a good working height with many convenient lumps and crevices to rest the free-end of the workpiece. To finish that particular episode, I also made a short curly piece to run from the feed-through union to the filter/agglomerator to the rear of the fuel tank. I could not fit and test it because I had run out of olives, which were added to the shopping-list. Once they were available it was a matter of putting the fuel can on the end of a dip-tube instead of the fuel lank and attempting to prime the system. Air continued to enter the system, however. "So it goes", as Kurt would say. A bit of judicious tightening was applied to the joints, and then I released the feed to the DPA injection pump so that I could just suck a sensible quantity of fuel from the can and see whether it was possible to draw any trapped air up to the top of the engine with the lift pump, using a small container to catch the output. That way the whole pipe-run through the repositioned filter could be tested. It began to look pretty good, so the feed to the injection pump was re-connected and it proved possible to pressurise that part of the circuit. After a short while I realised that the engine under the DPA was swimming with fuel, something that I had seen when starting the engine all those years ago. Clearly the leakage is nothing to do with the injection, but probably the seal on the pump body, which requires removal for attention. I spent a while practising the removal of the DPA from the spare engine, and didn't encounter any particular difficulty. I also had in mind that I had a couple of wheel rims awaiting clean-up for painting, now that the painting season is imminent. It turned out that the tyres on them were actually in remarkably good condition, though I cannot work out where they originated exactly. Not from Trevor Wigley because those were not Swift-pattern rims, but very probably from Chris Sullivan in exchange for my MB rims. One had blue paint that would have passed muster at Blue Lake, but green underneath all the flaking crud. Both had identical Kumho tyres, suggesting common origin. After seeking advice from a local coach company, I was told to take the wheels to Teiars Nant Conwy in Llanrwst, but first I had to get them into my car. Too heavy to lift on my own, and unwilling to be 'robust' around the Espace, I realised that getting them onto the gabions at the side of the garage apron would give me the height I needed. Pushing the wheels up a couple of steps wasn't difficult, and the floor of the Espace turned out to be at the exact height of my improvised loading-dock. In an extraordinary advance, Teiars Nant Conwy took the casings off for me on the spot for a very reasonable fee (with a promise to put them back when I am ready) and I arrived back at the garage in less than 30 minutes from setting off! Kurt would be speechless at that outcome!

Wheels on the improvised dock ready for loading. Photo © J.Wilkins

A trial bend for the bulkhead capping. Photo © J.Wilkins

I had become rather bored and disillusioned with fuel-pipes, filters and injection pumps, so I was looking for some quick wins, and a few presented themselves. Re-instatement of the air pipes which connect to the rear (high-pressure) reservoir was hampered by a stuck nut on the short run to the main foot-brake (front) line. Similarly, the tee-adaptor in that pipe was also solid, which was odd because I can't see how I removed the tank under those circumstances. However, we were where we were as the saying goes, and a solution was required. Eventually I managed to undo the nut on the tee, but only by rotating the pipe, which fouled the chassis cross-member as it spun. A certain amount of sideways force was applied, and only three revolutions were required before it was liberated completely and the job of freeing-off the nuts on both ends was commenced. Heat and judicious force won again! That will need preparing and painting before reinstatement. I had also been thinking about how to blank-off sections of pipe so that testing of my new joints can be undertaken. The external threads of the pipe connectors turn out to be 1" overall diameter, which is 3/4" BSP. No it doesn't make sense, but that is washing-machine hose size, and a blanking cap for that was only a couple of pounds from our local ironmongery store, Stermat. It was great, for a change, to find that it fitted just as sweetly as I had hoped. With another, I can shut-in the whole front-brake reservoir section for testing and see how we go on. I also raided my 'long materials' stores and dug out the U-section capping that fits onto the exposed edges of panels, the stuff of the wheel-arch mouldings, for example. A piece three feet long is required to finish the edge of the front entrance bulkhead, which was doubled in thickness by the addition of a new passenger-facing skin to assist with stress loading and plate-over the fatigue cracking at the waist. A short piece was cut for a gauge, which was fine, then another for a bending trial. The bend is required to match the profile of the entrance header to the vertical bulkhead. The position of the bend was marked, and then the heating started. Aluminium mouldings are supplied in a half-hard condition, and require annealing for a quality result and avoidance of cracks. My camping stove appeared to do the job admirably, though with all these things it is difficult to know whether the ideal 400°C has been reached. The piece was clamped securely in the vise with the bend mark at the end of the jaws and a scaffolding tube slipped over the free end. Obtaining the correct angle was determined with a bevel-gauge set from the bus body. I was delighted with the outcome, a sharper bend than I was expecting, and immediately cut the proper length from stock (with a small margin for error and trimming to suit) ready for another session. Two or three small successes there! Fabulous.

One day, recently, I was surprised by a small, enigmatic package arriving in the post, with nothing to identify the sender or content. Nothing expected from eBay, not even countersunk, solid rivets (see later). Inside was a radiator header cap! Complete with chain and jump-ring! Oh frabjous joy, callooh-callay, as Kurt definitely did not say. I had my suspicions, but initially the sender could only be localised to the Home Counties North Mail Centre by tracking the progress of the package through the Royal Mail. Anyway, I did find the benefactor, and I did express my thanks in person, but here they are expressed again. I have also been interviewing people who might have the knowledge to fix my dodgy fuel-injection pump, and will in due course undo same and take it away for service. I also performed the bending trick on the replacement metal moulding for the front bulkhead edge, and performed the first grass-cutting of the season in order to keep the grounds tidy. Preparatory work around the driver's seat entailed the removal of same, so I was exploring the lift mechanism. I had assumed, for no reason I could recall, that the lead-screw was rusty and seized-up. Not so, but there has been disassembly by my predecessors, and I think it possible that a new seat has been attached to the base. Getting hold of the parts with a big spanner (small ones don't fit) and turning the handle carefully showed that the exact opposite was the case, so it was lubricated and operated to full extent a few times. A new bar for the traveller to attach to the base is required - at present there is nothing to couple it to, so it just runs uselessly up and down. More material to source.

DPA fuel-injection pump (SMS637). Photo © J.Wilkins

Testing the new seals on the door-ram. Photo © J.Wilkins

A bit of a poor spell has endured, with a great number of jobs away from the bus. However, preparation of the entrance header area by cleaning internally and rubbing down externally has made a great advance towards refurbishment of the door gear. I have also made a new bar for the base of the driver's seat. It had to be strong, so I have used fabricated channel 30mm by 15mm in 2mm steel. which is still workable. It was a simple job, but hard work as it needed profiling to fit inside the base, and 5 holes to be drilled for the fixing bolts etc. Before the lunch-break I drove up the valley to drop off the newly-liberated wheel rims for shot blasting, so that's another job passed to someone else. Having originally been directed for pneumatic seals towards a company trading in West Bromwich, it was actually in Smethwick that the answer lay, although relayed through a Trafford Park office. I have a bias towards companies located in traditional centres of engineering manufacturing. After a bit of a wait, I received a quotation made out to London Country Bus Services - at which I almost fell off my chair. Anyway, the parts I needed were available from stock, or 3 days back-order, which hardly counts. Turns out the salesman had been looking online for who I was and the connection was quickly forged. Now, here is a sales pitch: if YOU need seals for the 1960s-1970s Peters door-engine ram, I have a sensible number in stock and they are simple to post. I could not simply buy the pair which I needed, it wasn't fair on the sales staff, but neither were they very expensive. I'd rather pay a sensible price for a repair than go totally cheapskate and annoy suppliers. In the end, I managed to fit a pair of new seals with nothing more than a bit of wrestling. I was also happy to have a few spare because I was seriously bothered about damaging one while fitting it, and yes they are on my shelf if you need one. I had, after all, broken one removing it - but it was probably old and hard and I made a point of warming the seals in hot water before attempting to fit them - and oiling everything liberally so that they would slip on prettily. The damaged washer in the exhaust-end plunger was replaced with a domed toilet-cistern washer that was unused from a 'universal' repair kit from ages ago. Yup, fitted perfectly after drilling a mounting hole! So, now I even know how the ram works, and it's not quite as I imagined. Lip-type seals can also act as a valve, so when air is admitted to the space between the opposed pair of seals it simply pressurises and the pair of pistons move to fat end of the chamber because the force on the big piston is greater than that applied to the small piston. The seal on the small piston prevents air escaping from the actuator rod end (or not, in the case of the damaged/worn item I inherited), and that is the default state of the ram (doors closed) because air is always applied to the central port at working pressure. If air-pressure is applied to the head-end control port (by the solenoid valve, or either emergency release tap) it can by-pass the big piston-seal and balance the pressure on both sides of the big piston so there is no force applied, and instead the small piston is driven down the thin end of the chamber, which opens the doors. Give the man who designed that a big, fat cigar! I was delighted to find that the pressure seal was perfect when air was applied to the central port - even holding-up while I had a well-earned cup of tea - so that job was a good-un! To finish off, I gave the ram assembly a clean-up and a coat of paint, together with the seat-base channel section. The Llandudno Transport Festival kicked-off the following day, so I'd be surrounded by functional buses for a change!

Well, in the end the Festival was a success, but largely because vehicle movements were kept to an absolute minimum due to significant rainfall on both the Saturday and Sunday nights, and in any case the Saturday road-run was compromised by road works on the route to Conwy, and any credible destination to the east. I was a passenger on the only bus known to make a transit of the Great Orme's Marine Drive, a Bristol LH with close associations to the Transport Festival, which ran to advise roadside observers that there would be no cavalcade that evening. Returning to the field we encountered a Sunday-only entrant that was doing a nostalgic tour of the Llandudno district, and a couple of passengers joined a trip to Conwy (which is still accessible from Llandudno through a section of single-lane road with traffic control on the Cob). The contrast between the bumpy and lightly-loaded Bristol and the elegant London Transport RF was extraordinary, so I enjoyed a very nostalgic magic-carpet ride with two photographic circuits of Conwy's World Heritage town walls. It was a surreal journey on a very familiar type of vehicle in a very familiar landcape, but the combination was bizzarre. I slept well that night!

RF539 loses its way to Bishops Stortford. Photo © K.Valla

After all the excitement of real, mobile buses I had to get down to the nitty-gritty and push on with my own immobile and seriously challenged machine. Grey undercoat was applied to the bits that were primed last time, and set aside to dry. While I was painting I was also thinking. It's a good time to think, but the thought that came to me was that I have to get my skates on, because the painting season only lasts until late September. Thereafter, low temperatures and low light take hold. I resolved immediately to find a nettle and grasp it firmly. The rear driver's side corner has always been a nightmare, and at present it isn't particularly easy to access, unlike the nearside which was treated to a new set of plugged fixing holes and screws last year. Shifting my podium built from pallets was easy enough, and with my set of kitchen step (retired) I was able to gain some visibility. The 'drip-strip' or flashing of soft, thin aluminium which goes under the GRP dome and over the side panel to form a seal behind the gutter has never sat well by the rear pillar and I have always been unhappy with the fit without understanding the problem. Until now! I was horrified to find that the dome has cracks behind the gutter where the fixing screws have been strained. I guess there has been a rear impact at some point. The upshot was that I had pushed the corner sheet into one of the cracks instead of behind the GRP, so that the length immediately behind the pillar was OUTSIDE and thus wide-open to water ingress behind the gutter, assuming that it could be screwed down at all. Only one thing for it - remove it AGAIN. Considering that those corners were one of the first jobs that I contemplated in order to continue and complete Ian Barratt's work on the body, they have actually been a perennial nightmare! Fifteen rivets and 17 screws later SM106 was starting to look like the bus I remember from way back. Pop-rivets are great when they go well, but often the mandrel snaps where it shouldn't and that is a real nuisance, because you cannot drill off the head of the rivet. Another blast from the past I could have done without! Luckily, the moulding came off without much fuss, but I had to wiggle and distress the rivet body until I was able to push the mandrel and other remains into the hole and I could contemplate re-assembly in due course. Flattening the drip-strip and pushing it carefully behind the GRP for its full length was the first challenge, then inserting the curved panel. Luckily, the drip-strip made a handy guide to prevent the sheet from running the wrong way again, but it was a sticky job because the mastic was being squeezed out of places it didn't want to be in. The non-hardening mastic was still quite soft, and I was able to clean it off the mouldings so as to make a neat job of re-attaching them once it was all lined-up with the fixing holes. Finally I just had to clean up by clearing excess mastic with a paper towel and white spirit. Three precious hours work - I wonder how long it would have taken a garage coach-builder in the old days at LH garage? The last task was messy and uncomfortable - getting to grips with removing the DPA fuel-injection pump. Not so easy when lying on the floor with your arms down the rear access-trap, but luckily there was sufficient oil and fuel around that the nuts were not seized-up, but still fiddly. One thing I found was very disturbing: the throttle push-rod assembly passes over one of the injection lines. Maurice noticed the worn, loose condition of the throttle linkage and took it all away for repair once the old Bowden-cable was removed, but what neither of us had spotted was that the vibrating rod had eaten a hole into a couple of the injection lines and I don't think there can be much metal left, so it will have to be replaced. When it was all undone I realised that I had omitted to disconnect the throttle and stop levers, but I could not face any longer in the Black Hole of Calcutta and I beat a retreat after putting some gloss on the undercoated parts.

Down the engine hatch, sans DPA pump. Photo © J.Wilkins

After a busy weekend away from the bus, during which I fixed three gates in two days, I took advantage of the Coronation Bank Holiday to get the job of removing the fuel-injection pump finished. Well, it was uncomfortable and took too long, but eventually a success. As I could not undo the short, flexible link-pipes for fuel from the lift pump and excess fuel return, they were undone at the manifold and disassembled once I could get at them properly. Unfortunately the operation disclosed that it was actually two injection pipes that have been abraded by the rattling throttle linkage, so we have to consider a way forward on those, too. In the picture you can see the injection pipes, and the aperture for the pump-drive from the back of the air-compressor and lift pump (also the filth, about which we will be able to do something while the pump is on sick-leave). I think it fair to say that leakage of diesel has been significant, and chronic. To finish the session I attached the new support bracket for the lift mechanism on the driver's seat, and installed the refurbished door-engine. I would have gone on to test it, but I was flagging by then and had to be home to make a family supper. Next trip down, I did test it! I made a stupid error in connecting the various pipes, but when I sat down with a cup of tea and thought clearly it was obvious. I took advantage of having to disconnect the valve assembly again by opening it up and giving it some TLC. Cleaning and oiling did not help much, still very stiff, but a smear of grease instead of oil did the trick and it worked easily and smoothly. So did the front doors once I had tinkered with the external release valve whose position was also completely unknown! It was very satisfying to see the entrance doors open and close under their own steam (or air)! Thereafter, I spent time on re-attaching the gutter moulding to the offside rear corner. The underlying wood work is not in good shape, but the alternative is to set about removing the rear dome - and that is not something I want to do. So for now I am plugging away at plugging the holes in the woodwork - eventually the screws will grip. It worked well enough on the nearside, but I think the offside has has a worse time generally.

On a fine day recently, I was able after some time spent on other time-critical projects, to get down to the bus again, but the most urgent task was to get the grass under a semblance of control, and burn the accumulation of prunings and brambles that had been drying at the bonfire heap. It was a very fine conflagration, and led me to ponder on the amount of energy which is sequestered by plants soaking up the sunlight. Once back indoors, it was time to get on with the gutter moulding. A problem that I do not understand is the way that the gutter will not sit tightly onto the corner below the rear dome, and the way that the holes in the gutter will not line-up with the historical holes in the dome. I have thought hard about this on recent dog-walks, and convinced myself that perhaps the gutter which I have inherited is actually not original, but I don't believe that the answer is known, except by one person who is so busy on restoring vehicles of inestimable value to transport history that I wouldn't waste his time by asking. So the problem is not so much understanding as how to recover and proceed. I looked at the problem from underneath, and realised that the sloppy fit is at the top, while the bottom of the moulding sits reasonably tightly on the curved quarter panel, and that's why no amount of cajoling or persuasion will make it fit better at the top. Now, if you wrap a flat strip around the surface of a cone, all sorts of geometrical anomalies break cover, and the natural tendency of the strip (or gutter) would be to spiral down the curved surface, and that is something that has to be resisted on our bus. Whether PRV actually solved that is a complete unknown, but to conform properly the gutter moulding must curve round the quarter panel whilst simultaneously becoming slightly shorter in the top arc than the bottom. That's a tough challenge, and not one that I am up to with half the length of the moulding still attached to the side of the bus! So now the game is disaster limitation and eventually I shall have to make a small bridge-piece to fill the short gap over the emergency window. I soon used up my remaining length of dowel for plugging the old screw-holes, but the ones I did last time took screws well after the PVA glue had set. Before it is fixed down it needs etch-primer, so all the recent screws were removed so that it could be freed and insulated from any existing paintwork. "So it goes", as Kurt would say, but he wasn't faced with cleaning-up 3 metres of gutter moulding! When you do a job like that it becomes apparent just how much minor damage can accumulate, and how badly-treated some parts have been. I suppose that the rear quarters and the gutter are the parts that get bashed most often - I wonder how many times they have been replaced? Most of the rubbing down and old-paint removal was finished by knocking-off time, which was no bad thing.