Working on a customer's bus, he told me there was an air leak somewhere. The main one was on the pipe from the tank to the unloader valve (refurb type, Knorr Bremse unit), where there was a long section of pipe unsupported, which had presumably worked a bit loose due to vibration. that was sorted ok with some thread seal.

But that then showed a second leak through a small hole on the reducer valve fitted on the air tank, another Knorr Bremse unit. An investigation showed the diaphragm split and leaking. Lucking the identity tag was still present so I called my local brake parts dealer who recognised the number but came back with the reply that the overhaul kit was obsolete. So was the unit, and a replacement was showing in excess of £200!

That set me thinking, you can buy a small adjustable reducer valve for a lot less than that, you know the sort you us on a garage air line system. so that's the next line of approach. Providing it has a locking device, you can set that at 65psi and hey presto, a budget solution to a problem. Just make sure the threads are compatible with your RM.

My bus number (if any): RML2532

Search for Bellofram on this site and you will find the unit I have used. Works perfectly and I believe was in the region of £70

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