HELP - Brakes are driving me mad...

[NikolaiV]

Hopefully someone on here can help with this:

I`ve been knocked back on my WOF because my brakes need adjustment. The power and balance are there, but the first pedal push goes to about 2' off the floor, with the second being sweet as a nut.

It`s a 1967 88" with standard 10" drums all round. All shoes are good (4mm thickness), both front drums have been replaced (and backs were within spec with plenty of adjustment left).

I know about the proper location of the return springs - they`re all good. Fluid is fine... Pulled the wheel cylinders apart and all look fine (clean bores, seals nice).

Only wierd thing is a funny almost whine noise from back brakes after releasing pedal??

Its almost like the springs in the wheel cylinders aren`t seating the shoes out far enough, and the first pump is seating the shoes, with the second engaging them from the proper location. This is probably it, because if I leave it after the second pump its back to normal (too much travel). But the springs on the trailing shoes arent strong enough to pull the cylinder back in without the assitance of the spinning drum...

But why???? and how do I fix it?

Answers gratefully appreciated.

[JDNSW]

If the pedal is solid on the second pump, then the problem has to be adjustment or alignment of the shoes. Assuming the adjustment has been done correctly it could be caused by an adjuster that is not staying put. If it is an early type with adjustable steady posts, these could cause the problem, and severe wear on the pressed bumps that replace them on later ones would have the same effect.

A suggestion is to separately clamp off the three brake hoses to determine which wheel(s) is the problem.

John

[LandyDude]

I had a similar problem recently. I had replaced all the cylinders (master and wheels), new shoes, new drums and yet the brakes were not happy. They gradually deteriorated. They would bind intermittently (even while driving), strange pedal behaviour (sometimes very hard, sometimes had to pump a couple of times).

After hours of trying to figure it out, turn's out the (new) master cylinder was crook. The seal inside it had a little nick out of it. The failing seal was probably a manufacturing fault right from the start and it just took a while for it to fail almost completely. I would not have expected a brand new compete master cylinder to be the problem, hence hours were spent looking for a fault elsewhere.

After replaciing the master cylinder, the brakes have never been better. I have no idea if this is of any help in your case. NB: Replacing the master cylinder is painful and awkward :(

[101RRS]

I am with John - brake linings.

On every drum braked landy I have had the same problem. The gap between the shoes and drums is too great - the first pump of the brakes pushes the linings out and the second push engages the drums. You say you have new drums then it is the linings.

If necessary go to oversize linings. With the snail cams right off (and make sure these are actually engaging the linings), the drums should be a snug but not overly tight fit over new linings. I had to use oversize linings on my series 1 and series 3 with good drums - in my 101 with first oversize linings the problem was still there with low but in spec drums - needed new drums to fix the issue - when new linings are needed I will need to go to second oversize linings.

As I said the first pump is taking up the slack and the second is working the brakes - so you need to find out why.

Garry

[ashhhhh]

I had the same problem and it turned out one of the adjusters on the rear was stripped.

When adjusted it appeared to hold... until you hit the brakes, at which point it came loose and threw the whole adjustment out.

[foz.in.oz]

Another thing to check is the post that the shoes seat on to. This post is supposed to be free moving in a slot and not fixed (single snail adjuster type back plate). If this has seized in its slot only one shoe will be being adjusted leaving too great a gap between the other and hence too much pedal travel.

[Newbs-IIA]

I had the same problem also with all new brake parts, I initially adjusted them according to the manual but found that they needed to be adjusted right up to make them really good. I could lock wheels in the dry at about 20mph on the first pump of the pedal with unassisted drums on my 109" IIA when done properly

[Bunjeel]

Hi, I don't know whether this post is still active but anyway: If you adjust all the shoes up till the drums bind and it still happens, then it's either the servo or the master cylinder. If the servo unit seal has a slow leak, fluid can leak into the canister and you won't see it. Then when you hit the brakes, the first push will pump it up and it'll be right from then on. If you pull out the servo vacuum feed plug and poke a stick down to the bottom, you 'll be able to tell if it's gathering fluid down there.
Otherwise, check the linkage between the pedal and the master cylinder. If it's set too far out, it spends too much time pumping fluid back into the reservoir before putting pressure onto the brakes - it does this more on the first push than the second for some reason.

Hope this helps,:)

John,

- just rebuilt the brakes on my SWB Series 2 A -