Thread: Urgent help needed bleeding series 3 brakes.

I don't know if its relevant to S3's but I had similar symptoms on an 80's porsche I rebuilt the brakes on. I put new rotors, pads and rebuilt the calipers (new seals, pistons, etc) however, I didn't replace the rubber hoses. Apparently, they tend to perish internally, so even though they looked fine on the visible exterior, they were deforming and not working properly where it coutned (where the fluid is). As soon as they were swapped out with new ones the problem was eliminated.

If it pumps up to give a hard pedal, it is not a bleeding problem, but adjustment, either at the shoes or at the pedal.

If it is not a hard pedal when pumped up, it is probably a bleeding problem. In either case, start by clamping at each of the three hoses to the axles. If the pedal is not rock hard at this stage, you can then investigate master cylinder pedal adjustment and if necessary bleed at the union to the master cylinder.

Then release the clamp on the rear hose, adjust all shoes to lock wheels, and bleed - should get a solid pedal. Reclamp the rear hose, and repeat procedure at each front hose.

An alternative to locking the shoes is to remove the drums and clamp the shoes in using a large G-clamp. This has the advantage of minimising the volume in the wheel cylinder. In either case, the adjustment factor is removed from the equation.

When bleeding conventionally, use several rapid strokes of the pedal. The bleed nipple should be equipped with either a one way valve on a hose into a container, or have a helper to close the nipple. Alternatively, reverse bleeding or power bleeding can be used.

Clamps for blocking off brake hoses should be available from any auto parts place, and are quite cheap.

It would help id you stated whether it is a dual brake system or not, but in any case, the same approach applies. Remember that you can bleed at any junction if necessary, and remember that air bubbles will rise to the highest point, but can be carried along by a rapid flow of fluid.

Hope this helps,

John

have you tried pressure or vacuum bleed?

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It pumps up to a hard pedal which then goes away. So you have to pump up again to get it hard again. The shoes are all adjusted to one click before they grip which is what the book says. I would have thought when the nipple was open the position of the shoes should not be relevant as there should be no pressure, once all the air is out and the nipple is closed then that is when a few pumps should self adjust the position of everything. I've read all the horror stories about bleeding these things and now it has happened to meand with all of the many cars I've had before I've never had so much trouble bleeding a brake or a clutch as with the series 3. It is always a 15 minute job with most other cars. Very frustrating.....

As JDNSW said, it is all in the adjustment. Only takes 1 shoe to be out and the pedal feels no good.

This is the foolproof order.

1: Back all adjusters right off.
2: Bleed from rear left, rear right, front left, front right, repeat,
3: adjust up each shoe until it grips, back off 1 click
4: done

Experience shows, that if you think you have bled it properly, you most likely have. Adjustment causes most of the pedal travel.

CC

umm guys he is talking about a land rover.
the only way to bleed the brakes is under pressure 14psi or more, unless you can get the front up on about a 40 degree angle.

mate pressure bleed your brake, i went through a full rebuild on a 2a before i done this.
i had new cv master machined drum and radius ground pads kitted wheel cylinders stretched springs new flex hoses. in the end all it needed was to be pressure bled.

Originally Posted by centy

umm guys he is talking about a land rover.

Umm, well I own around a dozen of them and mostly all series.

Never experienced problems in bleeding, be it single or double system, 10" or 11", boosted, remote boosted, blah, blah, blah.

In fact on a recent road trip, lost pedal and chased the problem. Dropped a lining from a shoe, rivetted it back on in the caravan park, only to lose it's mate the next day. Replaced shoes, disturbed the Slave which made it leak, honed it, cleaned it, Fixed. Rebled the front only. Pedal felt soft. Was advised to bleed the back, but guess what, 1 shoe out of adjustment due to wear from compensating from the dropped linings.

We are talking about Land Rovers indeed. You should try investigating and rebuilding things, rather than just replacing parts willy nilly to no obvious effect.

The simple old 3 pumps, hold and crack is still the best way IMHO. As long as you have 2 people. Nothing against pressure bleeders, as I am getting an expensive proffessional one with a bladder seperating the pressured air and fluid, but so I can do it solo, and for no other benefit.

CC

Originally Posted by pfillery

It pumps up to a hard pedal which then goes away.

If it pumps up to a hard pedal, it is bled, and the problem is with the adjustment or the master cylinder pushrod adjustment.

The shoes are all adjusted to one click before they grip which is what the book says.

This is the theory, but it assumes the shoes match the drums and are in the right position. Adjust up until they are locked, back off one click, apply the brakes hard, and then recheck them all. Also, be aware that adjusters have been known to fail to stay in position. If the drums are out of round, assembled with dirt behind the ledge they sit on, or the shoes badly lined or with the springs in the wrong place, the brakes will grip with plenty of motion left, giving loss of pedal.

I would have thought when the nipple was open the position of the shoes should not be relevant as there should be no pressure, once all the air is out and the nipple is closed then that is when a few pumps should self adjust the position of everything.

Yes, and this is what happens when you pump it up. But as soon as you take your foot off the pedal, the shoes will come back against the adjusters, and you are back where you started.

I've read all the horror stories about bleeding these things and now it has happened to meand with all of the many cars I've had before I've never had so much trouble bleeding a brake or a clutch as with the series 3. It is always a 15 minute job with most other cars. Very frustrating.....

I have been working on these brakes on and off for almost fifty years, and have yet to encounter this sort of problem. If there is a problem, it is normally fairly obvious if you understand how they work.

John