So some of you expressed a interest in the outcome of my decision to fit a electric compressor to replace the belt driven one fitted to the gearbox so here is the progress so far!

Background
I wanted to fit a Compressor to my Routemaster that would be capable of inflating/topping up tyres when need on my planned adventures with my RM but also replace the compressor on the bus with a unit that will help the bus stay on the road in the future.



Outcome
After days of research and going through technical sheets, I settled on a 24v Twin Compressor made by ARB (of Australia) designed to be used in harsh off road situations and recovery unit and its capable of running air tools with no tank require.

The compressor is effectively 2 separate compressors linked via a manifold with a pressure switch of "<135psi On - >150PSI off" but with separate feed wiring and relays for each compressor.

This means I could spilt the wiring loom and adapt the wiring to suit my 2 purposes.


Above I am missing 2 switches and a box to mount the switches and relay in, seen on the top left - (Still in the post)

My set up enables me to select either 1 of the compressors or have both running together.
A switch that lets me select 135-150psi for efficient tyre inflation or 90-110psi for normal bus operation.

The air tank (with a minor leak) last between 20-30 minutes (depending on how many times you change gear)before re-pressuring is required and takes 32 Seconds from empty to 110PSI.

When the higher pressure setting is selected it also uses a 3way Solenoid valve to closes the feed to the air tank and opens a feed that a air line is connected to for the tyres protecting the air tank from the higher possible pressures.



I have mounted it under my stairs as that is where my batteries are and its just convenient for my set up but when it is all closed up it a lot quieter then expected and will be even quieter when mounted on dampeners.

It is designed to be mounted under the floor or in engine bays and is easily small enough to do so which would make it next to silent from in the cab/saloon but for me the stairs was good enough!

ARB do make repair/service kits for these including the piston chamber so its life is not a short one! But with my set up I plan to only use one piston (doubling tank pressure time to 1 minute) so the I can use the other piston as a back up.

My bus number (if any): RMF2771 (RCN 701)

I'd suggest you fit a cut-out switch on the air line to the tank, so it cuts out at 110psi and cuts in again at about 75, a bit like an unloader valve. One of the benefits of an electric compressor is that it doesn't have to run all the time.

My bus number (if any): RML2532,GS67,MLL721,MLL738 and an RT.

RM 371 has an electric compressor fitted, not to operate the gears as it has been Dartmastered. It's for the platform doors. The compressor is fitted under the stairs.

Roy,

Plan to but everywhere seems to be out of stock of one's in that pressure range with out being one ment for 240v compressors and In a big black box, I need/want a small one that screws in a 1/4bsp fitting. So I am making do with 90-110psi til I can get one.

My bus number (if any): RMF2771 (RCN701)