Brakes - Adjusters that dont!

Post by **tricky** » Mon Mar 03, 2008 12:43 pm

I have a 1971 pick up which has been off the road for some years and is now coming back to MOT standard (Slowly)

The brakes were none existant but after a new wheel cylinder some new pipe and a bleed I thought it would be ok.
I tried to adjust the brake shoes but they were at the end of the adjustment.
New shoes were then fitted but I still had the same problem. The shoes would not quite adjust up enough.
Worn Drum? I changed the rear pair for new drums but still have the same problem.
Are there different adjusters available or or I doing something wrong
Help please

Post by **alex_holden** » Mon Mar 03, 2008 1:15 pm

I think the adjusters for the 7" rear drums are smaller than those for the 8" front ones. Could they have got mixed up?

Post by **bigginger** » Mon Mar 03, 2008 1:25 pm

They are - just found that out, and just rebuilt front and rear brakes, so know it's true
a

Post by **tricky** » Mon Mar 03, 2008 6:16 pm

I am sure it has to do with the size of the adjuster and the rear on the front is a good line to check. Any ideas for the rear which also does not adjust properly

The old shoes which were in it would also not adjust even though they had plenty of lining left. They were replaced really because they were very old and quite glazed.

Thanks for the ideas - Keep em coming

Post by **MoggyTech** » Mon Mar 03, 2008 6:31 pm

If front to rear adjusters are mixed up the front won't adjust up, but the rears should. Assuming everything is in the correct place, it could be new shoes are slightly undersize, or drums have been skimmed too much.

You can add a shim between the adjuster pivot bracket and the wheel cylinder to compensate for worn adjuster or over skimmed drums. However, the shim needs carefull shaping to ensure it cannot slip out. It should be a tight fit in the wheel cylinder recess.

Note that over skimmed drums will overheat quicker as they are thinner and that means less metal to absorb the heat.

Post by **tricky** » Mon Mar 03, 2008 6:48 pm

The rear drums are new out of the box from a morris minor specialist as are the shoes.

Post by **Willie** » Tue Mar 04, 2008 8:45 am

It would appear,since the drum and shoes are new, that the rear brake cylinders have seized up unless you can see them actually moving. They can move when the hand brake is operated but this doesn't mean that the hydraulic pistons situated underneath them aren't seized. The front adjusters for the 8" brakes are 10mm across the screwdriver slots whereas the rear brake adjusters are only 7.5mm. The question is, do you see the shoes operate when the pedal and/or the handbrake are operated?

Post by **tricky** » Tue Mar 04, 2008 12:35 pm

One of the wheel cylinders is brand new the other moves freely. the problem is that i cant get the shoes adjusted to the drum (ie taking up free play ). I havn't even got as far as checking things like pedal travel as it takes 2 pumps to bring the shoes onto the drum.

Post by **bmcecosse** » Tue Mar 04, 2008 2:41 pm

First step - are the adjusters moving ok when off the car ? If so - they WILL adjust up on the car! I too have used the 'shim' - but only with used shoes. New shoes will not need that.

Post by **Willie** » Tue Mar 04, 2008 6:51 pm

Concentrating on the rear brakes for now. It is impossible to have the wrong size shoes on as they were always 7" so, if the adjuster moves the shoes but will not make them contact the drums there is something weird going on. With new drums and shoes you should have difficulty refitting the drums with the adjusters backed right off as they would normally be a tight fit. My unused spare rear shoes measure 7mm across the lining AND the metal base combined. What do yours measure?

Post by **tricky** » Tue Mar 04, 2008 9:28 pm

Willie wrote:Concentrating on the rear brakes for now. It is impossible to have the wrong size shoes on as they were always 7" so, if the adjuster moves the shoes but will not make them contact the drums there is something weird going on. With new drums and shoes you should have difficulty refitting the drums with the adjusters backed right off as they would normally be a tight fit. My unused spare rear shoes measure 7mm across the lining AND the metal base combined. What do yours measure?

From memory - around 7mm - The car is at my father in laws house as he has a garage its a mere 100 miles away so I only get to play every few weeks.
I spoke to a supplier today who supplied the new cylinder, drum and shoes and came up with a potential problem. the car was "restored" about nearly 20 years ago - Has done little and has been garaged all of that time - standing for the last 4 or 5.
At the time of the rebuild parts were quite hard to come by so the adjusters themselves may not be correct for the drum or even the car. they are loaning me a pair of correct rear adjusters to check if that is the problem. Will let you know when I find out. Sadly it will be couple of weeks till I can get on it again.

Post by **bmcecosse** » Wed Mar 05, 2008 8:09 pm

Try the adjusters on the car but with the drum off the brakes - sometimes the end of the adjuster 'snail' can catch on the edge of the shoe - giving the impression of full adjustment when in fact there is plenty to go. A wee rub with a file on the offending 'catch' point will give you the full adjustment range.

Post by **rayofleamington** » Wed Mar 05, 2008 11:38 pm

Try the adjusters on the car but with the drum off the brakes - sometimes the end of the adjuster 'snail' can catch on the edge of the shoe

just beat me to it - I've seen this nearly every time with new rear shoes

If they really are on the end of adjsutment, the adjuster cam will go round and round and round. If it's fouling the shoe it will turn then stop before the shoes are tight to the drum.

A wee rub with a file

AKA - pick the angle grinder up...