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New Owner- Couple of Questions

We recently took possession of RM2133 and are very excited. We hope to get some picture on the website of the move and the conversion we will be doing. I am also a new member in the RM Association

I am a gas turbine engine technician an have several diesel vehicles so have some experience with mechanics, but am at the beginning of the learning curve with the bus. I had hoped to post some pictures but haven't figured out how to do that.

When driving the bus over to the mainland from Vancouver Island, the red flag would randomly go up and down, with the brakes light coming on as well, however often a brake application would cause the flag to go up and extinguish the light. On occasion just motoring down the highway, the flag would drop and then go back up.

I have replaced the front brake lining and the rear is good, and the brakes seem to function well.

I was hoping someone could point me in the right direction to troubleshoot this- I have a copy of the maintenance manual, but again, am not sure where to start.

My bus number (if any): RM2133

Re: New Owner- Couple of Questions

You need to re-charge the brake accumulators. They need to be charged with about 38bar. some people use an intensifier, others use nitrogen. There's details in the various owners manuals how to do it or on the South Devon Railway website on how to do it.

My bus number (if any): RML2532

Re: New Owner- Couple of Questions

Hi Lorne - welcome to the wonderful world of Routemaster ownership! As Roy says, the info you need is @ www.RM1872.org.uk along with lots of other useful and interesting info.

My bus number (if any): RML2302

Re: New Owner- Couple of Questions

I had the same problem when I purchased 2616. Which was 8 year ago. If after recharging your accumulators if the problem still exists
Get someone to check the unloaded valve on the accumulator.
The unloaded valve was the fault on mine.
Regards Brian.

My bus number (if any): RML2616.

Re: New Owner- Couple of Questions

Thank you for the welcome, I have found the information needed and source out the parts to make a charging rig.

I have the Lockheed system on mine and could not find reference to an "unloaded valve", could this possible be called something else in the manual? In any event, I can dig into that if need be.


The other question I have is, how "power" should the power steering be? Should I be able to turn the wheel with one finger?

Also is it typical that the bus slow down considerably on slight hills?

Thanks you, I look forward to your responses

Lorne

My bus number (if any): RM2133

Re: New Owner- Couple of Questions

Hi Lorne It's power-assisted steering rather than powered steered so it does take rather more effort than one finger but not too much. I'm sure others on this forum can tell you how to check if there are any faults in the system. The unloader valve is part of the air system which supplies the air pressure to operate the gears - as the name suggests, it "unloads" excess air pressure when an adequate level has been reached - you can hear a sort of sneezing noise when it operates. I don't believe this is relevant to the braking system which is hydraulic but I'm ready to be corrected. Slowing down dramatically on slight hills shouldn't happen but again I think others here will be able to help more.

My bus number (if any): RML2302

Re: New Owner- Couple of Questions

There is no unloader valve on the brake system. the air system is purely for the gearbox. If the accumulators won't hold their charge, then the answer is to get them changed. Imperial Engineering can do this but they won't supply abroad. It is a specialist job rebuilding those.

Any bus will slow down on hills, especially a bus that is over 50 years old.

My bus number (if any): RML2532

Re: New Owner- Couple of Questions

Hiya all. . Unloader valve is called a pressure regulator valve. ( Still an unloader valve in old days. )
Brian

My bus number (if any): RML2616.

Re: New Owner- Couple of Questions

Thank you so much for all the responses, I am slowly getting to know the systems on the bus- very interesting. I found a picture of the unloader valve in a technical write-up on the site. The nomenclature takes some getting used, when I first heard the terms "nearside and offside" I had no clue (got it now)so even our North American terms for things differ.

I have some friends in the UK and some contacts for arranging parts so if I need accumulators I can get it sorted.

Thanks again

My bus number (if any): RM2133

Re: New Owner- Couple of Questions

Bought the parts to make a charging kit, we had a Nitrogen bottle at work I could use. Pretty simple task once you have the parts.

One accumulator had 400 psi and the other had about 80.

All charged up and the flag goes up right away.

Thanks for the help.

Now I need to make test rigs for the air and hydraulic systems so any hints on thread sizes of fittings etc would be appreciated

My bus number (if any): RM2133