A customer in Austria had problems with his MoT today, so I had a fun half hour on the phone trying to tell the Austrian vehicle examiner how an RM brakes work...in German! Oh the fun of bus restoration!

The brakes were ok with the engine running, the accumulators give 7 pumps before the flag drops, but they wondered why the brakes didn't work with the engine not running after about 10 minutes! Hohum, so much for Single European Type Approvel.

My bus number (if any): RML2532

The Flag must not fall for a minimum of 10 minutes after the engine has been switched off having just fully charged the accumulators.

On a standard pre-refurbed RM when you stop the engine on the Aaron's cable the flag drops anyway doesn't it?
Bit puzzled as to why is it necessary to drain out the accumulators whilst the engine is off on an MOT type test. The accumulators are essentially an emergency braking resource that in normal circumstances should never be used, why would you need 7, 10 or 12 applications of the footbrake if the engine had stopped?

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

I agree with what has been said. The current UK regs are that the reserve brake pressure should not drop within 20 minutes.

I presume they tried the brakes with the engine stopped to see if the brake reserve works with no pump being driven.

I don't know whether the bus passed its test as my customer hasn't phoned back yet.

Last time I took a bus for test here, the examiner wanted me to sit there with my foot on the brake for 20 minutes. My leg gave way after 5 minutes, so I explained to him the usual method was to see how many apps there are before the flag drops. On my bus, it was about 28!

My bus number (if any): RML2532

Carried out correctly, the tester ought to check on the roller brake tester, that once the flag has fallen there are two further brake applications which record some effort. He is instructed to release the rollers' drive as soon as effort is indicated.

I gather this is what they done, but some time after the engine had stopped, so no residual pressure and no brake effort. With the engine running, all wheels locked and 36% handbrake.

I also tell presenters to stand on the brake pedal as the last 10mm gives full line pressure and "should" cause the wheels to lock.

My bus number (if any): RML2532

..and the dent from the conductor's head hitting the heater duct!

My bus number (if any): RML2532

At arriva while getting the bus ready for mot. Rms had to meet 9 brake apps

I would generally accept 8-9 apps as a decent minimum to attain.

BTW, the bus in Austria got it's ticket, so a happy ending there.

Off to Neuss and Strasbourg in the next week or so for yet more brake overhauls!

My bus number (if any): RML2532