If this picture works I will continue with some info



It did work! And editing available as well! The following was (almost word for word) placed on another Forum recently. While I had replies (ta to those that did) I still have not found a supplier of this or an alternative part. Having spoken to David Cooper this week I understand there are a number of bus people here that do not visit other forums and I should look at this one. Anyway here goes:

The part shown is a Reducer Valve. It is fitted to the air tank outlet. Now the problem with this is that the amount of moisture that enters the valve and sits in the bottom (where the 2 bolt plate is) rots the spring which allows the rubber disc to fall back from the valve and an air leak occurs from the pin hole in the dome. This is evident by the hissing sound and, if you put your finger over the hole on the dome, by feeling the air escape. Other symptoms are gearbox warning lamp illuminating and the loss of gears especially when shunting and therefore constantly changing gear with little or no revving of the engine.

My spring previously failed but purely by chance I had one in a small collection of RM parts electrical components I own. Of course it has again gone (and within three years)

Problem is no one seems to recognise the part.

Having read LBL specification no SS034 (the RML refurbishment specification issued in 1991 for quotation purposes) I have found that it was suggested to contractors that a WABCO 475-010-0120 should replace the original item although an alternative part may be allowed but must be passed by LBL first.

I have searched the forum and found a number of discussions about this including possible suppliers. For the record;

IMPERIAL ENGINEERING ' of Cheshunt in HERTFORDSHIRE: Not air parts. Brake valves and accumulators only

AIRLEC TRUCK & BUS PARTS LTD Phone: 01772 698100: No. not in use

Assured Performance Group Ltd: Not for obsolete items. Only modern parts dealt with now.

Fleet Parts, Very helpful but they have said the above item is not a Wabco item but do not recognise it anyway.

Since being told this I have realised that the fixings (4 bolts on dome cover and 2 bolts on flat cover) are imperial not metric and that implies these are the original units. That said it doesn't really resemble the part shown in the Walker manual. So does anyone recognise it, have a part number and or a supplier for the part or better still a part number and supplier for a repair kit or even just the spring.

Alternatively I have found a spring manufacturer that will copy (what is left of) the spring but the cost will be around £5.00 each plus our postage cost to you should you want one/some. I will probably need to purchase around 50 so please do let me know if you have a requirement. (price will be around £10.00 for 3 if I buy 100). The downside of this is not knowing the potential usage for the springs as other Routemasters may have a different part

One more thing. A quick fix to enable shunting although I would not recommend full running or high revving as I do not know the consequences, is to place a jubilee clip over the dome to partially block the air hole.

Any thoughts and what does your bus have fitted (part numbers and or pictures would be useful)

David

My bus number (if any): RML2276, M1001, T806

Rob Duker shows two reducer valves on his RM parts listing.http://gallerybob.fotoblog.co.uk/c1917004.html

If that doesn't help Mark Prescott at the Manchester Museum has been a big help to us in the past with valves and informtion, are there any numbers on any of the casting bodies to give a clue to manufacturer?

My bus number (if any): RTL 960 RMC 1458 RM 1585 and several RTs

Hello David,

I have just read through the full posting on Alan's Forum and because the last entry was some time ago, it would seem sensible to reply to the latest post.

While everyone wants to limit expense as much as possible, the answer is surely a new valve that is set to the correct pressure and that has ports in the correct places.

One of the answers appears to list possible replacements.

Is your bus a refurb or original?

I have some notes and photos from RML2644's air-system, but they're on a different computer. I do recall finding manufacturer details and part-numbers on some of the castings for the various air-system valves. I'll try to dig them out this evening.

Brian

My bus number (if any): RML2644

Thanks for the replies. The problem I have is that all of the suggested suppliers either do not recognise the part (any suggested part numbers), or do not deal with said part or indeed any air parts or no longer exist. I am fully aware that I can find a modern version and adapt but I am surprised that no one, on either forum, has said oh yes I had the same problem. I got it repaired at........, I got a new one from............ or even I got a modern replacement from here..........
Rob's pictures show the item but not a definitive answer as to where to buy or get repaired. One forum "member" has had an identical fault and replaced their spring but not with an original. The problem with that is the spring is designed in a certain way for a reason. What could the consequences be of a different spring pressure. Too little and a leak will occur. To much and presumably no pressure relief can occur, what then? I can get a modern unit and adaptors etc but, well I could do the same with lots of bus parts I would just prefer not to if possible. The manufacture of springs is one way (like some others we are looking at manufacturing various parts at the moment) but I have not had any feedback as to whether this is a much used part or a rare variant of what is what is commonly used and if that is the case what are those more common parts.

I need to get my bus MOT'd next week so I will go ahead with a repair one way or another but in the mean time can some of you please take a look at your bus and see if you have one of these or a different type so I can get some ideas of quantity. I guarantee if you have one of these that spring will fail at some point.

David

My bus number (if any): RML2276 M1001 T806

Hi David - I admit it folks, I am that "member" who replaced their spring with one modified from one in a £3 mixed set of 100 bought from our local market. It is still working OK but I agree it's a bit worrying that it isn't just the same. It does seem odd that the original appears to be a tiny very delicate conical spring made of steel in a place where it will inevitably be exposed to water. I don't really understand how it works but I can't believe the pressure it exerts can be as critical as the big spring which acts against the diaphragm and which has to be set to the correct pressure and I feel reasonably confident that the high pressures in the system could easily overcome the small light spring. It must be safer that a jubilee clip over the relief hole. Maybe someone who does understand how it works could reassure us! Mark P ??!

We had the very same fault with 66. We stripped out all the air valves cleaned up all parts and replaced the springs with spares found and adapted in the garage! works (and cant be seen)!

My bus number (if any): RM308 & RM66(Group)

Anyone foolish enough to fully cover the vent hole and for anything other than emergency shunting deserves the results. That said is it any less dangerous to fitting the wrong type of spring even if or perhaps especially as it cannot be seen. We have no idea what the consequences of jamming home fully with an oversized spring the rubber disc that prevents air leak. There are no gauges on a Routemaster so one would have no idea of the resultant air pressure.

I will purchase the modern item as it seems none of our esteemed bus mechanics have any suggestions for the repair of the original.

My bus number (if any): M1001 RML2276 T806

This story is a case where the benefit of building up a relationship with a (hopefully local) parts factor can show rewards over trying to source either secondhand parts, or attempting to deal with the factor’s supplier in an effort to obtain the best price. Become a ‘face’, a ‘voice on the phone’ or better still, a ‘name’ that they recognise as an even occasional customer who doesn’t waste their time and their willingness to investigate whether they can supply what you need or a suitable replacement increases noticeably.

The really good parts factors hang onto old catalogues and the associated technical details. Given the above relationship if they cannot cross reference what you want, they will be prepared to contact Grau technical, or whoever, for assistance.

A valve that has been in use for a long time will have been exposed to contamination by water, carbon and oil so the diaphragms, seatings and springs suffer as a result. Very frequently as soon as the rubber components are exposed to fresh air and cleaning fluids they swell up and are useless. One of my local factors recently showed me an air valve which would have cost about £80 a few years ago, what he showed me was plastic, made in China and priced at £47. To have dismantled the aluminium version, cleaned, inspected, reassembled, adjusted and tested it would have taken probably about an hour; this is the reason for overhaul kits not being available.

This has long been an argument.
At what point is a safety component no longer reliably serviceable?

Many components on Routemasters are now obsolete and, in some cases, so are the manufacturing processes and raw materials.
Some are simply cosmetic like Rexine or the table tennis rubberoid used on some surfaces. A substitute can be found as near as original or one scours the planet for a remnant.

When it comes to a part that makes the bus (or any vehicle) move, stop or steer, then it is a little different. Safety has to come first.

I'm sure most bus observers have read last week in the trade and national press the antics of Metroline and how the findings of inspections are now to lead to new regulations and that may well have serious ramifications for operators and private owners.

Bodging is simply not acceptable. We will not tolerate it from our engineers and we will only allow them to use ingenuity on rescues ONLY if it does not compromise safety.

If it is the practice to refurbish (and a lot of RM components were specifically designed and contracted to be fully serviceable,) a few things ought to be factored in.

1. The item should be serviced using correct methods and original specifications.

2. Due to a components age and useage, Is it still within servicable tolerances?
Wear may be too much to make replacement components operate as reliably as they were intended. This would mean that the components need to be adjusted to take up the wear tolerances. This applies to seals and moving parts.

This would be almost impossible and prohibitively expensive.

The better option would be to use a current component that meets or preferably exceeds the original specification.
This would at least be cost effective but in the case of safety and peace of mind, the prudent option.

As another contributor pointed out some time back, many car clubs with larger purchasing power have joined forces with parts suppliers and created a 'Better than Original Equipment' market.
It's more expensive in outlay but much cheaper in the long run and much safer too.

In the case of a spring made of steel, it was designed for a shortish life and constant use. Lack of use and the british climate will accelerate decay. So the logic would be to have a non-corrosive spring to the correct tensions manufactured (which should be cheap but probably 3 times the cost of a steel spring. But it will last 10 times longer.

Several improvements to the RM exist due to this principle.
When parts were in short supply and Aldenham was coming under the cost cutters microscope, I vaguely recall a piece in LT News where a chap in the pipe shop suggested a change to stainless pipes and joints to increase the life of the pipes and joints.
I think he got a box of quality street for his suggestion which saved £££££ in paint and so on!!

Hello Jack

You are clearly in the industry. Maybe an ex LT BM or better still a Fitter? You have covered pretty much everything in your last post and I agree with most if not all of what you have said. I would imagine other ex LT (or other RM operators, current or former) mechanics or fitters would also agree. As stated these items appear obsolete and if not being repaired are presumably being upgraded to modern equivalents. And finally, at the risk of stating the bleeding obvious, this is a forum where thoughts ideas and experience is shared.

My question is then why is no one (except a couple who have fitted non standard springs) telling what they have done to overcome the problem OR are these items actually very rarely fitted and another readily available unit is the norm OR do they actually not fail very often at all. Or is it simply few have bothered to look?

Also is this the original item or a later fitted part either as a replacement for previous now obsolete parts or simply as a part of the refurbs? Someone must know this surely?

I would gladly have had made a stock of springs if I had received justification in the form of "Yes, most Routemasters have this fitted" or a high quantity of individual "yes we have one." Equally I would have stopped any further talk of spring building if mostly "No we do not have this item, we have this......" had been returned.

Rob Duker is building a nice collection of photographs to identify parts. Some of us have access to LT BEMS manuals also useful when trying to explain the part to another bus owner but even with part numbers added to this information we will not find the parts unless we share the information of where to buy and how to carry out modifications if it is a new part being used. The sister website to this forum has some great info, very informative but we need more. Well I do at least.

My current thought is to buy a modern regulator with a pressure gauge, mount it somewhere accessible with flexible pipe extensions. If it works I will gladly write it up for includion on the website.
Any thoughts anyone.

David

My bus number (if any): M1001 RML2276 T806

Hello David.
I suspect you are right, right and right again.
Ignorance, undetected/identified problem and, possibly, no problem.

I also suspect that many OE parts are no longer fitted and that later parts are fitted to many vehicles.

Remanufacture can only really be determined by identifying a need and a commitment to purchase. This is where co-ordination and cooperation becomes important.

I am surprised that BEMS is not on a website anywhere after all it was simply the book stuff being put on to the microfiche and then on to the computer system.

It's really useful as long as it has the invaluable cross reference of part numbers and stock stuff. Although several editions are well obsolete it could form a basis to shore up the gaps since LTs demise. Could be a lot of painstaking work though.

Maybe the RMOOA should aim to have it as an access portal to members only via it's website although it would probably be still licence copyright to TfL. It might well be a worthwhile investment to purchase a licensed copy
Maybe someone at TfL/LB/LTM knows more.

It would compliment Mr Duker's excellent efforts in bringing things up to date

Unfortunately even if the BEMS software was still available and could be run on a pc (i think it was a bespoke system) it would still mainly lead us to part numbers that are obsolete and suppliers perhaps long gone. I spent a large amount of my time at LT using the BEMS system to provide me with breakdowns of wiring harnesses for amongst other vehicles, the Metrobus. (My business began as a supplier of harnesses to London Transport). Also with the amount of uncontrolled garage level modifications and even the refurbishments which was left to the contractor to make final decisions little of it would have made it onto the BEMS system. There was, I am told, an update for the individual companies to use prior to sale but whether that is available or usable I do not know. Are any readers still in a position to find out if a system still exists or made it into privatisation that could be found if the right people are asked.

I have elsewhere suggested the creation of a database that could be updated by members (as and when one traces and buys a part), that could show each part (with a photo even), a part number, where purchased and what bus it was fitted to. That would give us an idea of where to look when we needed a similar part. It would only need a place for it to reside on the internet and someone to ensure it is not abused. Reference to the BEMS manual pages would also be useful for when tracing parts

David

My bus number (if any): M1001 RML2276 T806

David
The problem with sourcing parts that are no longer available in original condition and specification is that unless others have had the same problem nobody knows who to go to or where to look for one.

Its not that people are withholding information, its just that they just don't know the answer to your request. Never had to find one of these valves for our RMs so have not had the problem you have, when I do I will start here and with the suppliers in the RMA booklet, then contacts I have built up over the years. Its no good looking at the ex LT staff and expecting answers, RM parts were hard to find in 2003 and with refurbished and re-engined RMs the task became even harder. The BEMS material might be useful, provided an alternative item was identified in BEMS days, if not you are back to knowing the Chiswick part number of the item you have. WABCO are as far as I know part of Westinghouse, so I would start there and find the exact spec of the valve you have and see if there is another product that can be adapted for use from say a comparable vehicle like a VR or another AEC product. Welcome to the world of sourcing parts for old buses!!

My bus number (if any): RTL 960 RMC 1458 RM 1585 and several RTs

Brian. You could well be right and no other vehicles (as in RM’s owned by regular forum readers) have had this component fail as yet. Maybe in a few months several will be asking me for advice.

The withholding information bit, well I look at it this way. I have been an electrician for 31 years, a number of them working on LT buses. If I saw on this forum a question that related to my trade I would do what I could to answer it. I am not aware that I’ve ever ignored anyone’s question. I have put this issue on two Routemaster forums. I believe both are visited by people that have worked as Bus Mechanics or Fitters for London Transport during which they have encountered Routemasters. Some appear to have worked during the 1970's others perhaps later. Now while I cannot tell you every part number , I could pretty much point out every electrical component, it’s position and function, the wiring routes within the bus and the position of the electrical panels on Routemasters, Metrobuses, Leyland Nationals, Leyland Titans and with a bit of thought Bristol LH's. One would think therefore that a fitter or BM reading this would recognise if the valve pictured above is;

1 the original type of valve used..
2 a part fitted during the refurbishment programme.
3 a much later part fitted when original parts were in short supply.

Especially as at least one or two appear to be making a living from repairing buses still.

If it is not withholding information (and this is an information forum is it not) then I can only assume they are not as knowledgeable as I thought.

I think the information received thus far is from enthusiastic owners that have had similar problems. Those I thank.

RE your BEMS comments, I said as much above. Nice and pretty to use but not really useful and almost certainly never updated.

RE Wabco. I have traced I think every company that has been involved, WABCO, Westinghouse, Knorr Bremse etc. as well as all of the major vehicle component dealers and agents plus those ex LT people that now supply parts and a few others. Few recognise the part numbers suggested and those that did have none and do not have the repair kit. If the unit had broken in half, or seized up or some other catastrophic failure I would have found a modern replacement by now, but we are talking about 10p worth of spring. That is all that is wrong.

David

My bus number (if any): M1001 RML2276 T806

David
I understand your frustration. If you cast your mind back to the garages, electricians and Bus mechanics had totally different jobs. Then factor in the time since any of them worked on RMs, my brother who you probably know last touched an RM as a B/M over 40 years ago, he helps when he can as he did recently in helping the French RML owner with his brake shoe change, but he cannot remember every detail of what was on an RM, remember B/Ms just changed parts,like for like,they didn't have to know what went on inside the part or attempt to repair it, the units went back to Chiswick, as far as I know there are no fitters who worked on the benches at Chiswick on any bus forum. There is one person who has not contributed to this who may know the answer, he might be off-line or sick, but I will try and contact him for you and see if he can help.

Cheers

My bus number (if any): RTL 960 RMC 1458 RM 1585 and several RTs

I had a brief look under a refurb RML yesterday, unfortunately it was getting dark, I had moved the vehicle outside, my torch battery was fading, the ground was still wet, my extension lead would not reach to get a lead light closer and my belly would only just squeeze under the lifeguard of the vehicle how it was parked on its four wheels.

This vehicle had what looks similar to the valve pictured, the manufacurer's tag is intact, but I was wearing the wrong glasses and the tag was in the wrong plane to read. Next week I will record the tag number, compare it to the numbers you already have for Clayton and Bendix and ring a local factor.

The valve in the picture is totally different from the two pre-refurb vehicles I looked at on Tueday.

From what I could see and can interpret from your picture, one has to remove the air tank on the bus I was looking at in order to get the reducer valve off.

Whether the other refurb bus to which I currently have access is the same, I don't know; I can't remember. I will make a guess that it is at least similar. I will have a look the next time I go to where it is kept.

If it is necessary to remove the air tank on your bus too, I would not dream of messing about trying to get a spring sourced, when another of the internals may fail next month or it may have to come off again because one of the unions is leaking.

Given that RT and RF dynamos and control boxes are somewhat delicate, borderline in performance and fabulously expensive to repair, even if the control box innards can be found, I'll ask : What would you do confronted with a failure? Do away with the DC system and fit a Metrobus alternator along with the wiring mods and a specially made pulley, wait however long to find another dynamo, control box, or the particular currently unobtainable failed component, or have the failed units overhauled?

Should all tag numbers come up as no longer superceeded, the Bendix RV valve shown in the link from Alan's Forum looks as if it could be made to fit reasonably easily and without having to remove the tank.

I've had a brief look under 2391 and taken a quick photo , also had a look underneath another RML which was at the same shed AR as 2391 . Can email photo if you wish to compare , the reducer seems similar .
Of interest the air system is fitted slightly differently , on 2391 the air tank cylinder points forward and on the other RML the tank points accross the bus , with associated pipework slightly altered to fit to/from the tank . Wonder how many other variations there might be ? Perhaps there could be a few other types of reducing valves fitted on other RM's

Mark

My bus number (if any): RML2391

Talking of different valves fitted,
I do not know if this will work, but here goes.

RM1797, Its a Scania refurb


RML2261, Its an Arriva Bus


RMA58 STD AEC


BEA1


RM17 STD AEC


RM13, Air Tank etc ready to go back

My bus number (if any): RM13

Rob
All your pictures with the exception of RML2261 show Clayton reducer valve APSA1490 series which is obselete, kits are still available for it, one such supplier that comes up easily with a web search is http://www.majorsell.co.uk/acatalog/APSA1490.html although i have not used them, the only draw back with the kit is that you have to cold ally rivet the diaphragm onto its mount as per description on the above link (B69RK004A SERVICE KIT)

2261's reducer valve must be nearer the gearbox.
This valve was also used on Metrobuses!

David

KX542/7 was superceeded by SKX542/1 (you set the pressure yourself to 5.5 bar)and was fitted to Dennis Dart SLF and MPD (Dennis part no.653540)there is no reference on the web to kits for it just the complete valves in Italy and Russia and Hungary.

All that info was found on the net other than trawling through an old Bendix catalogue that I have access to.

With regard to your problem your choices seem to be
1, Fork out a load of money on getting a number of springs made in a better material in the knowledge that no-one yet has come forward to say that they will have some (some people will not have a clue what valves their bus has and some people will only buy when they need rather than get as you go along)

2, Fork out a load of money for a new valve if that firm near me will sell you one (given the Fire Brigade aren't going through them at a fast rate - 1 in the last 2 years?)or source one from abroad - even more time and money

3, Fork out less money on a RV type valve or similar and spend a bit of time and faffing with the pipework

Regards

Mark

My bus number (if any): RM1414 sort of and others too numerous to mention

Great pictures Rob. Glad you've cracked it!

Here is a picture of the B67RK007A kit.

My bus number (if any): RMs 238, 471 & 2213

Hello Chaps. This is a quick reply and I may not have read all of the above fully yet. I will look deeper later.

Wow. Lots of replies. I have done some more searching as well and as mentioned above the KX542 is now SKX542 and are stocked by Knoor Bremse. They have directed me to HGV direct in Chesterfield who are trying to find an alternative source as Knorr have a list price of £278.00 less discount which brings it down to £231 plus VAT. Knorr Bremse do not have a repair kit listed.

Knorr Bremse own Westinghouse. They in turn bought Bendix. This Valve is originally a Bendix part. The repair kit picture above seems to have a lot more parts in it than are in my valve although the spring does look very similar but when one searches for B67RK007A that is a Wabco part, Wabco being the owners of Clayton Dewandre. I suspect the original parts were Clayton. I have previously asked for these at all the suppliers mentioned above and no one has them.

I have carried out a temporary repair 9adapted spring) to allow me to go for an MOT.

I will report back

David

PS

Now I have read the above and my notes from when I started looking for this part I'm afraid I new all of the above except that the valve is available and is £231.00 and that there is a probable chance that the original part is a Clayton changed later to the bendix part on Sheffield refurbs. Others (Enfield or Nottingham was it) may have used the Wabco replacement. Also has anyone checked that the repair kit located is still available from Majorsell. It may be that part that they initially told me was available and then realised they had none on the shelf and would not be getting anymore.

Roy

The tank does not have to be removed (not on my bus anyway). The angled connector is to a pipe that once released allows the valve to be unscrewed from the tank. Only just though. Was your account of trying to get to the valve deliberately funny?

My bus number (if any): M1001 RML2276 T806

Just for completeness and any future reference these two pages I posted on Alans forum are from a 1974 Bendix catalogue






Mark

My bus number (if any): RM1414 sort of and others too numerous to mention

Chris Dobbing

Great pictures Rob. Glad you've cracked it!

Here is a picture of the B67RK007A kit.

My bus number (if any): RTL 960 RMC 1458 RM 1585 and several RTs

Mark P

I was just dragging the same drawings over! as well as typing the following exactly as worded in issue 1 of

SPECIFICATION FOR THE REFURBISHMENT OF ROUTEMASTER VEHICLES

SPECIFICATION SS034

1 Mechanical

1.3 AIR TANK

The existing air reservoir, unloader valve, pressure limiting valve and associated pipework is to be removed and replaced with equipment supplied by WABCO as follows

10 Litre Reservoir 451-010-3000
Unloader Valve APSA2878S1
Pressure Limiting Valve 475-010-0120
Standard ISO Test Point

or acceptable alternative manufacture as agreed by LBL

Reservoir mounting brackets and associated fittings (with the exception of pipework) available from Wabco, or acceptable alternative manufacturer


I have gone over my notes again and I have previously spoken to Majorsell (Fred according to my notes). They said APS1490 is the Clayton version of WABCO APSA2878. They also said they can supply the repair kit (which is GA28865 or B69RK004A) for APS1490 but it would be without the springs! all for £11.80. Even though the kit has similar parts to my valve the spring is the very bit I need.

So to me it has not been "cracked" after all except that for £231.00 I can buy a new valve or for £100 I could buy enough springs to last a lifetime (yes I understand other things could go wrong with it)

I have re approached some of the companies previously contacted. I may find a different member of staff will to go a bit further. I am also now looking at replacing whatever is necessary with modern parts. I will let you know.

David

My bus number (if any): M1001 RML2276 T806

Sorry Brian, yes, the picture is the 04 kit, not the 07, sorry.

My bus number (if any): RMs 238, 471 & 2213

Even more confusing

I misquoted as well by copying Chris's B69RK007A number. My notes say B69RK004A. The former is just rubber parts. The latter is though (according to

http://www.autosluzby.cz/asl_katalog/asl_katalog/pdfdwnload/MAJORSELL%20WABCO%20valves%202009.pdf

nothing like the picture posted by Chris. Not really relevant to me as my valve is the Bendix/Westinghouse/Knorr Bremse version anyway.

Bloody hell this is difficult.

My bus number (if any): M1001 RML2276 T806

David
APSA2878 is (I strongly suspect)the unloader valve as fitted to RM1797 and BEA1 in Robs pictures so it is unlikely to be the Wabco equivalent of the reducer APSA1490 series - I think that a lot of confusion exists as to who bought who (which you have straightened out) and also the comparable (ie same purpose) valves between Wabco and Knorr Bremse.

Mark

My bus number (if any): RM1414 sort of and others too numerous to mention

Eagle eyed folks will see that there is a rebuilt APSA type reducer listed today on Ebay.

http://cgi.ebay.co.uk/ROUTEMASTER-REDUCER-VALVE-/140505367778?pt=UK_CarsParts_Vehicles_CommercialVehicleParts_SM&hash=item20b6c5c4e2

Not my part or listing!

My bus number (if any): RLH62