Terrano/Mav brake judder !?!

[LouLou]

I replaced both front disks/pads on our Terrano 2 months ago and for a long time it was fine. Or at least no-one told me it wasn't.

I grabbed it for a few days last week and noticed the judder and found that both front bearing preloads were a little slack and had to be tweaked up one notch. Tracks much better but the judder is still there when braking from +50mph. Stripped both wheels off yesterday and no play in either bearing or upper lower arms. No visible distortion in the disks either. Both calipers checked and they are nice and free.

The only obvious item is the front anti sway bar ball end fittings (anti-roll links?). One looks shot and the other has ragged rubber bushes. It is almost metal to metal contact. Could this be causing the problem? I have ordered a pair of anti roll links anyway and a new set of poly's for the front and rear anti sway anyway.

Cheers,
Paul

 

[LouLou]

Well I replaced the front anti roll bar bushes....and the back and the same problem existed!

I have seen the same problem with my Cherokee with a hairline crack in the new disks. This would opening up as they heated so assuming the same I fitted yet another new pair (last set had done around 1500 miles! so anyone neeed some?) .....and I still had the same prob. So it wasn't the disks.

In a fit of despiration I dropped the truck off at the local speciaist who put it on a rolling road and said it was the rear brakes and it looks like the drums have gone oval. Well they were the orginal ones from new and have seen 150k.

So £110 later a new set arrived. I checked over the existing shoes (like new so save a bit there) and linkage. What a Heath Robinson set-up that adjuster system seems to be? Lubed everything after a good clean down with brake cleaner. Set up the new drums and adjusted the handbrake. Initially it was fine but now the juddering is coming back, though not as bad at the mo. Hit the pedal hard at 60-70 and I can feel it easily.

Now this is seriously bugging me and along with a few other niggling jobs that need doing is making me feel I should get this shifted and replace with a newer model or use the Jeep.

I don't think we have ABS on the Mav (no manifold assy I can find) and I have never seen any sensors or a castellated hub so what can it be? Only thing left as a bolt on job is a new pair of rear shoes, but the old ones were like new and I cannot for the life of me see why they would cause this issue?

Pleeease. Anyone have a constructive suggestion :roll:

.45 is loaded and ready to put the Mav out of it's misery

Paul

 

[Toolbox]

Sounds like you have been having a pig of a job to sort this problem. I presume the shoes had no sign of oil contamination on them?
I wonder if it could be related to the load valve in front the rear axle.
Can you feel it through the steering wheel? Is there any noticeable judder of the brake pedal?

 

[LouLou]

Load valve?

Yep, I can feel it through the steering too!

No sign of oil contamination in either drum when I swapped them. Just heavily worn. Even the linkage was in good condition and the shoes looked to have been changed in the last 2 years.

 

[Toolbox]

If you can feel it through the steering you would think it would be the front brakes at fault.
I know you have said that all the callipers are free, what about the pistons are they free moving

 

[LouLou]

When I say through the steering I mean the whole car can shake. I stripped both front calipers and checked them for sticky pistons. All are free ?

I am starting to think this car is on it's last legs. Just found the exhaust has split just after the flexi coupling into the main exhaust pipe! Temporary repair now made with a steel beer can/exhaust paste/jubi clips. Seems solid - for now :lol:

 

[LouLou]

Well I have taken the drums off today and they came off easily and there was no drag from the shoes. So they don't seem to be binding. Most weird.

:?:

 

[AndyM]

Possibly the brake servo unit

 

[LouLou]

You may have something there Andy.

Stripped the drums off last Sunday to look and see if I had overlooked something before and found nothing. Just gave them a clean.

Antway while I was under there I found the flexible section of exhaust that comes as part of the downpipe had completely rusted through and was direct some exhaust gas 'at' the rest of the pipework and the rest was just blowing out. Banjo repair with a bit of San Miguel can/exhaust paste/jubi clips and jobs a goodun'. Much quieter now !

Now what is weird (isn't this whole saga?) is the brakes are now fine. After 100 miles they are not juddering at all. So :-

a) Some god or deity has willed the Terrano brakes to work instead of me losing my rag with it.
b) A little more cleaner on the friction material fixed it. Doubt that.
c) It something to do with the backpressure from the exhaust and therefore the performace of the engine anf therefore the brake vacuum?

Most importantly it work now :roll: :lol:

Paul