A Mec seeks B mec

Yes I’m a 17-year very experienced A Mec but I have very little serious experience on the Heavy B Vehicles (Technical side I may add). And I am looking for a B Mec with my cap in hand because I’m after your expertise. As I have just been dumped into a heavy B vehicle repair line.
Here is the problem our inspection departmet (bless them) are failing numerous heavy B fleet vehicles for brake angles exceeding 90 degrees. The area they are referring too is from the actuator to the brake-applying arm. This is all French to me as they are all passing a brake test while the applied brake angle is very very near or just past 90 degrees. However this is supposed to be illegal, this is due to loss of braking torque once it is past the 90-degree mark which I can understand. Now before I dig into a mountain of AESP looking for a possible + - factor % and get out of date or incorrect info or hopefully the correct info, which may be in French (A Mec pun). Is this a common failing in our dated B vehicle fleet, as this seems to be aimed at the Air brake fleet? Any info or feedback greatly appreciated. The reason this is being asked as this is causing a immense amount of work to regain this 90 degree mark, please keep in mind that the vehicles are having drums and shoes renewed and at times the angles are still not being achieved this is as you can imagine keeping high profile vehicles of the road. Not to mention the cost in labour and parts just to gain 2 5 degree’s

Ps the inspection department are currently getting the info that they are following in black and white (AESP) so at least I can see why my guys are getting F**ked about.

TIA (thanks in advace)

PPS serious replies first please before i get all the abuse about amec seeking b mec ;)

Hi Mate,

I'll freely admit to not having much experience with B Vehicles, but a lot of C vehicles use the saem braking systems you are referring to.
Now, it's a while since I got my hands dirty, But I seem to remember that there's an immense amount of adjustment possible not only on the length of the actuator arm, but also on the feckicantrememberwhatitscalled that the actuator pushes.

I've had a quick google for some suitable images to show you what I mean, but have been unsuccesful.

Is it possible you've overlooked one of these?
How exactly are you carrying out the adjustment?


jobman, I thought that they only help when they....SEFIT. But they should be able to sort it, more chance than some others from the corridors of the DLO
Thanks for the info and the PM, and yes the inspectors are following the letter of the law. But they are without a doubt 2 of the biggest arses i have ever met. retired reme guys with a massive chip.

As BFG says, there is adjustment in the actual actuator arm that should reduce the angle? i see you say the brakes are being re-lined and new drums fitted. (was the first thing i thought as i started to read the thread).

Are the "S" cams worn? The rod that the actual actuator rod rotates should have a cam on the end to move the brake shoes? i have seen these worn on an 8 tonner more than once and cause similar faults even with new shoes and drums. In fairness these usually failed brake test also however.

Hope i dont sound as if im stating the obvious as im fairly sure you have deductucted this from the equation, was only offering another possibility......

if it helps i was an A mech!! sometimes the wheeled world can be traumatising!!
Without knowing your exact circumstances i can only give the following slightly drunken " advice ".
1 It shouldn't be your problem, push it up the chain of command.
2 AESP's are not always correct or current, inspectors are quick to quote them when they don't have to repair the kit. However they are our bible so again any challange to the authorized publication should go up the chain of command.
3 Policy dictates we RBT vehicles for a reason, if the vehicle passes but the inspectors still insist there is a problem why do we bother to do a RBT ?

At the end of the day the vehicle has a valid printed RBT report, surely that should be a big enough umbrella ... :wink:

Don't get me started on 601 vm tasks, what a waste of time they are...

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