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wierd brakes

Posted: Thu Jun 08, 2017 5:43 pm
by surfergirl
Ok so today the van passed his MOT...YAY!!!!!...but his passenger side front brake is dodgy. It has new drums..the cylinders arnt that old, pads are newish but they always seem to be skinnier than they used to be. What happens is, as its put on the rolling road and he presses the brake the ps one is slow on the uptake, thus it lags behind the other side till its nearly at full, then it catches up and the pressure is the same and good. im at a loss as what to do next, ill prob get some new shoes, and maybe replace the pipe from the switch to the flexi hose but after that ???? any sugestions out there . cheers in advance

Re: wierd brakes

Posted: Thu Jun 08, 2017 5:49 pm
by Sleeper
Sticking slave cylinder...? (on the slow side )

John

Re: wierd brakes

Posted: Thu Jun 08, 2017 5:52 pm
by ManyMinors
Have you checked that the pistons in the brake wheel cylinders are completely free moving?
Your car won't have "pads" unless it has disc brakes but what do you mean by "skinnier"??
I assume you are refering to the brake shoes?

Re: wierd brakes

Posted: Thu Jun 08, 2017 6:38 pm
by surfergirl
Yes sorry I mean shoes. Think my cylinders are OK. Not been on that long. The lower shoe doesn't have as much lining on it as the top one... I'm going to replace these as first port of call. Just got to find some good ones tho. These were Borg and beck but I'm not liking the fact that they are just glued now not riveted ( had a rear one part company earlier in the year) I can remember when I used to replace shoes you used to have to manhandle the drum back on cos they were so beefy...now we don't seem to have that problem anymore.

Re: wierd brakes

Posted: Thu Jun 08, 2017 10:36 pm
by beero
Renew the flexies as well. One of them could be collapsing internally and restricting the flow.
Check for sticking wheel cylinders.
Also check the springs. Could be the passenger side has stronger springs or they are fitted in the wrong holes.

Re: wierd brakes

Posted: Fri Jun 09, 2017 7:18 am
by RobThomas
I had an imbalance in the take-up of the rear brakes on a Lenham Midget many years ago. Changed everything without success. Turned out that the return springs were wrong on one side, thus holding off the shoes until the springs had been overpowered by the pressure. One set weak, the other side were much stronger.

Re: wierd brakes

Posted: Fri Jun 09, 2017 7:59 am
by MikeNash
Dear Surfer,

A couple of thoughts. Re brake linings, if you look up your copy of "Morris Minor 1000 Owner's Workshop Manual" by J H Haynes (published in 1971) you'll see that on page 117 the brake lining material for the 1098 engined car (8 inch drum?) is specified as Ferodo AM8 and for the 948 engine car its MR11 (7 inch drum?), and all the illustrations show the linings riveted to the shoes. There're a number of specialist classic brake lining companies around the country (I don't know them perhaps others will - 'spect Phill and Mr Islip will be along in a moment) but quality linings might help you; a chat with the firms regarding current versions/replacements of Ferodo (or Mintex) materials might be fruitful. Re modern linings, I find that going down Hurstbourne Hill in our village on the A343 with a loaded Trav requires the strength of a giant in the right leg if I want to get thro' the S bend at the bottom with any dignity. Although I'm getting on, I'm sure it didn't used to be like that.

Re glued linings becoming detached, I've never known it on Moggies before, but on some British classic bike it's a real threat. 1950s Ariels such as mine with aluminium alloy shoes had (and still have) glued linings which perhaps have their own particular problems. The solution has been to reinforce the adhesive by drilling and fitting a pair of rivets at the linings leading edge.
Regards, MikeN.

Re: wierd brakes

Posted: Fri Jun 09, 2017 1:37 pm
by philthehill
http://www.autoandindustrial.co.uk/inde ... ompetition

Note the internal link to riveting brakes and other internal links relating to brakes and brake materials.

When bonded brake shoes first came on the market there were some failures but I cannot remember the number being excessive.

With well known branded brake shoes that is those bonded using ISO or British Standard products/procedures should not be subject to failure.

The best policy is to fit the best brake shoes you can so as to give peace of mind.

Re: wierd brakes

Posted: Fri Jun 09, 2017 1:56 pm
by shoebone
Pattern front cylinders get a bad reputation, I understand genuine cylinders and Mintex shoes are the way to go .. er, .. stop

Re: wierd brakes

Posted: Sat Jun 10, 2017 6:57 am
by kennatt
the question is does the car pull to one side on braking? if not just forget about it,could well be a fault in the test machine,if it was pulling indicated by brake imbalance,it would/should have failed mot . So I wouldn't fret to much.

Re: wierd brakes

Posted: Mon Jun 12, 2017 6:42 pm
by simmitc
You mention that the lining on the bottom shoe is thinner than on the top. This suggests that the bottom shoe is doing more work. This might be expected on the rear brakes which are single leading screw and reply on the cylinder sliding upwards to exert force. However, the front are twin leading shoe and should work evenly so I suspect that the cylinder for the top shoe might be a little slow. It's still working, hence no imbalance; but would account for the lag.

As mentioned above, "original" cylinders and Mintex shoes are the way to go, plus check the flexible hose.