Brake efficiency

[disco1]

Could anyone please advise as to the best methods to get a brake efficiency pass at the mot test station. The reason i ask is because i cannot compare my 1965 saloon with another vehicle. I am worried that the brakes are poor, as in comparison with a modern cars brakes mine are feeble. I have just about completed a complete restoration of my car and have new brake pipes and new front cylinders fitted. The brakes have been bled and i believe no air is present.
The brakes activate at the end of the pedal travel, do i need to pump them up more or is the master cylinder possibly faulty? Your input would be be valuable as i do not want to waste the mot examiners time.

Regards
Chris Discombe

[Willie]

Lo, if the pedal goes down a long way but feels much better
if you pump the pedal rapidly then that indicates that the linings
are too far from the drum i.e. they need adjusting. if the pedal
feels 'spongey' then you have air in the system somewhere.
The rear brakes can mislead you, the hand brake adjusters
should be FULLY slackened off before you attempt to adjust
the rears,when done you then adjust the cables so that the
road wheels can only just be turned by hand when the hand
brake is pulled up 3 clicks.
The other confusing condition is if you have uprated the front
brakes from 7" to 8"?? The backplates can be on the wrong
side....giving trailing shoe action instead of leading shoe.
If the master cylinder is faulty you will usually find that if you
press hard on the pedal, and keep pressing, the pedal will
slowly go down to the floor.
Willie

[Cam]

The brakes on a moggy do feel very poor compared to a modern car, and so you should not compare them really.

If your brakes feel 'spongy' then that usually indicates air present, if when you reach the end of the pedal travel the pedal feels solid and the brakes are operational then it sounds like the brake shoes are in need of adjustment or you may have an airlock or the pedal needs adjusting.

Try adjusting the front (and rear) shoes as described in the Haynes manual, and make sure that the breather hole in the cap that screws into the top of the master cylinder is not blocked.

If these items check out OK, then make sure that you have adjusted the pedal travel into the master cylinder to the specs described in the manual.

If you have not got a Haynes manual, then I suggest that you try e-Bay, as you can usually pick one up for a couple of quid.

If you are worried about efficiency, jack the offending wheel up and use an axle stand for stability, then get someone to apply the brakes and try to turn the wheel by hand / arm as much as you can. If you can't budge it (without blacking out trying!!8)8)) then that is a good indication that it is fine.

Also, make sure that the wheels turn freely when the brakes are not applied, as I have had more failures through brake binding than inefficiency.

Hope this helps.

Cam.

[Cam]

OOOPS!! Sorry Willie, looks like we were posting at the same time!!

Cam.

[James - St. Helens]

Have just done the brakes on a 71 moggie. Consisting of new brake lines, cylinders, shoes, master cylinder rebuild. The car had only just been bought ( We had got it through an MOT ). Not knowing what the brakes should feel like but having a sponge feel that we could not get rid of. We took the car to the local MOT station and paid £10.00 for then to check the brakes. It passed with a result better the standard required for the MOT. We still feel that the brakes are not right. But we have the peace of mind of the MOT brake check. I would say that if you are not sure you brake are OK take it to a MOT Station and pay for them to be checked.

[Willie]

Lo James, If you have fitted new shoes all round, the brakes
will not have that lovely 'solid' feel until the high spots
have worn off the new shoes after a couple of hundred miles.
Still, they passed, so must be reasonable....they will get better.
Willie