Can anyone please help me?
I have a problem getting my trafic van through an MOT at the moment. I am really desperate because I need this van to move materials and tools away from my property I have nearly finished and into my garage. The previous MOT has expired.
The rear brakes and the handbrake have failed the test but the garage I used cannot find any evidence of air, leaks or anything like that. The linings are fairly new but should have been given plenty of time to bed in. There doesn\'t seem to be evidence of contamination at all. This garage is not an MOT test station but uses one a few miles away.
The load compensator near the back axle has been suggested as a possible cause by the MOT tester but has been discounted by the garage.
I seem to remember having this problem before on a previous vehicle. I changed the shoes for another pair I had but hadn\'t used and this did the trick, but these shoes are new....
Any ideas would be greatly appreciated
Thanks
H
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Bit difficult to answer as you don't give the specific reason for failure, i.e. lack of effort or imbalance. However, I suspect that the load sensor can be ruled out as the cause of the problem for the handbrake as this is cable operated. If everything else is in order , shoes clean and roughened up, drums clean, cylinders working properly. Then it is probably adjustment. De-adjust the handbrake till it's slack and make sure the H/B levers are as far back as they can go. Then readjust the shoes ignoring the auto-adjuster ( wind it or click it on with a screwdriver ). Try putting a couple of bags of cement in the back as this should open the load valve and give more effort to the footbrake. Let us know the outcome.
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Thanks Greaser PV,
I mis understood what the MOT place were trying to tell me. The Handbrake was basically OK, but there was no improvement on the footbrake.
The load sensor was actually so slack that quite a bit of back axle weight would have had to be present just to take up the slack. This was adjusted to take the slack out altogether and try to open it up a bit, without any back axle load.
However, this again made no difference. The MOT test station suspected that the piston inside was seized, and they were right. A few carefully aimed knocks with a small hammer and application of pressure during footpedal operation freed it up. They re tested and passed the brakes and gave me the MOT certificate on the spot. All for a fiver!! They have suggested that I replace it soon though as they were concerned I may have the same problem again later. I think I'll be taking this advice.
Many thanks for your input
Hugo
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i'm pleased you're sorted, however I agree with the MOT station in regards to replacing the valve, because if the piston was stuck then there is a good chance that the internal rubber seal around the piston may have stuck too and when the piston was freed off the seal (washer) could have torn . This may not be immediatly apparent. For peace of mind put a new valve on and bleed the rear brakes. Thanks for letting us know the outcome, it makes all the difference.
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