LT policy was that drivers didn`t need to know anything about the braking system other than it was a requirement to not drive away before the flag had raised and the white light went out or to pull over and stop if the flag dropped in service. How many brake applications the bus had didn`t feature in training. Nor did exhausting the system and letting it build up from scratch to check how many applications could be got. The idea that anything less than seven applications was a cause for concern would not have been known to drivers. The most troublesome, problematic bus bus I ever encountered was RM 6 at Stamford Brook. Three applications was about normal on it. How it came through a rota inspection like it is open to question.

Rightly or wrongly, the assumption was that everything was in working order unless proof was there otherwise. Ten minutes signing on time was all that was given which in the case of some of the bigger garages was barely enough to walk from the operating area and into the garage to find your bus, get in and get going on time.

I fully accept the issue regarding time and fumes, however that reflects 1950's thinking and also the maintenance regime in use during commercial operation. Today's world is a blame culture society with the buck stopping at the person responsible for the condition of the vehicle. The DVSA is quite clear about this, the driver is required to complete a walk around check for every vehicle he intends to drive and to sign it off as roadworthy. As has been proven, he is among the ones who will be in the dock and possibly in jail if it is not so.

While it might be slightly unfair to expect an employed driver to know how many brake applications a bus should have, or maybe to bother checking that the flag/warning light system works, since enthusiast owners seem concerned to have encyclopaedic knowledge of the correct shade of red or the garages which operated their vehicle, I would have thought that confidence that the vehicle's brakes would work when required if there should be a failure in part of the system and that the warning system is operating correctly might be of some interest.

Over the years this forum has seen various queries about flag bounce while driving, one of the causes of which is low accumulator pre-charge air pressure. We have also seen questions relating to the failure of the brake hydraulic pump quill drive. Should this fail or the drive belts break, whether the bus will stop or not is dictated by the stored air pressure in the accumulators and the settings for the low pressure microswitches of the warning system triggering the flag and warning light.

A check on this was part of routine rota maintenance. Since these buses are now no longer required to have an MOT which never checked certain aspects of this anyway, perhaps we are just waiting for events to unfold.

As far as walk round checks go with preserved buses, sadly I can’t remember witnessing any owner I know carrying out a proper one before taking a vehicle out on the road, just as most car owners don’t ? Obviously those driving PSV’s for a living for a well run company are required by law to be in the habit of performing strict checks, filling in paperwork and signing off the vehicle before use, they also have a paid time slot in which to do it in. The top copy of the check is usually left at the depot and the book is in the vehicle for scrutiny by any official who requests it while out on the road. There isn’t a more valuable cargo than people ?

My bus number (if any): RML2747

The way I worded it is just the way I was told when we first got the Routemaster.

In practice, yes the flag is always already down when I do the checks, so there is no need to make it drop. Obviously, I wouldn't drive if it didn't go up.

Many thanks for all the comments.

I believe engineering check how many brake applications before the flag drops, at the inspections every few weeks. 10 sounds familiar.

I'll ask, because it's a hilly area and someone should be checking. If engineering aren't, then we should!

The wording of the DVLA testers manual was something along the lines of "sufficient reserve to make an emergency brake application". Having discussed this at length with a vehicle examiner at Mitcham Testing Station may years ago his view was that one application before flag drop met the criteria. I would be concerned if it was down to 3 apps, but 7 is what a lot of people mention.

The other wording in the tester's manual reckons the flag shouldn't drop within 20 minutes of the engine being stopped, and some on test have made me wait that length of time to see if it happened.

A few years back one of my clients in Germany had the flag drop outside Munich. I suggested that if the handbrake was working correctly, he should be ok to drive the short distance to the overnight stop (no passengers on board) using the handbrake. He reported to me the footbrake still worked and the handbrake was ok. When I got to the bus a couple of days later, I found the pump had failed and as the bus had relatively new accumulators, they had sufficient pressure to replace the plessey pump for a while. When I checked them they still had about 38 bar in each one.

However, another one abroad, an open top RM with Scania engine (roy knows what one) had constant flag problems. It couldn't be resolved in the time available but the accumulators were ok. In Spain going down a hill the driver said the flag dropped. Bus not slowing down, he applied the handbrake.that too failed to work, nor did the horn, approaching a village with red traffic lights. As luck had it the bus stopped eventually, the flag went up and the brakes worked again!

When it eventually arrived back in England we found all the brakes were so far out of adjustment, with the rear shoes not touching the drums with the handbrake on. There was a problem in the foot valve which meant the fronts didn't work and the accumulators were empty. Yet it had been driven round Europe like that. the client whinged when they were given the bill for the repairs to that bus.

My bus number (if any): RML2532