Thread: Weird brake noise even after servicing brakes

if brake fluid was crappy looking black/green colour, chances are high that the pistons may be semi or fully seizing up in the calipers .. one or two or more.

Caliper kits aren't super expensive, and it'd be something I'd do without hesitation if doing the brake fluid.

I suppose the noise could be from a partially seized piston, which could be skewing the pads a little. .. or something to that effect.

I haven't done my D1 calipers .. or even looked at the brakes at all! .. but the D2 calipers were pretty easy to rebuild.
I don't remember my RRC calipers were particularly difficult to rebuild either way back in the day.

Just a word of warning re caliper rebuild kits too tho:
Try very hard to avoid buying off ebay, unless you are 101% sure that the seller is reputable, and will sell parts that fit.

The D2 I recently did was brothers. I have a spare D2 I'm slowly wrecking, so the plan was I'd do the calipers off the spare, get them all ready so that the time we spent doing his was simply changing out his calipers, pads, disks, and fluid.
That is, to save us a couple of hours of the rebuild.
Plans go awry, when you look for the 'best price' for the parts tho.
He got some 'good deal' on the seal kits, and pistons .. except that the seal kits were not the right ones.
I briefly measured up each O ring seal, they looked OK, but the thing I should have been weary off was there were no markings on the new seals, where the LR seals had some orange and white markings on the seals.

Anyhow .. about 3 days later after much banging, mashing, hitting, heavy mallet work, heavier sledge work .. nothing would get the pistons into their allotted recesses with those seals in!
Pistons went in nicely on their own, seals went into their grooves nicely without pistons .. but together they just wouldn't go in.
I finally had the idea to get a new seal kit for them(actually ripped two seals trying to force them in!) .. and 'ya wouldn't read about it .. they went straight in, no problem.

I then measured the seals I got locally(about $50 from a brake supplies shop) with the god-knows-what type of square section O ring brother was sent! ... but there was about an 0.5mm difference in thickness of the actual square section between the two seals.
Seals I got had the orange and white marks on them as per the LR types.

Moral 'o the story .. don't skimp on brake parts.
Obviously if you do the pistons and seals, it means all new fluid all over again.

Major difference in the D2's braking afterwards too .. but that did involve new pads and disks and .. well basically everything!

D1 uses an engine driven vacuum pump thingie, which is infamous for not always working according to design specs! .. another thing to look for.
Note too tho, if this is your first Rover, they've always had 'harder' brake pedal than almost all other cars I've driven. My personal preference too tho.

You said you replaced the front rotors, so can we assume not the rears? Did they feel OK. You probably don't have a dial gauge to check, but I reckon you could mock something up if you can secure it rigidly to test for runout on the rear disks.

You also didn't specify ABS or not.
Not all have it, so it's not something to assume.
If you have ABS, could be an ABS issue.

ps. mine doesn't have ABS, and bought for this very reason(I hate it!).

Thanks Arthur. I think you're on the money. Seized piston might explain it. Especially if it was on the trailing edge therefore the leading edge is getting pushed into the rotor, would also explain why it doesn't happen when applying the brakes in reverse.

After hearing about your piston replacement I'm hoping a clean up and some copper grease fixes it for now.

Originally Posted by chillman

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After hearing about your piston replacement I'm hoping a clean up and some copper grease fixes it for now.

At the least, a seal kit is advisable.
If the pistons have some rusting, you could probably polish them up with some fine wet and dry paper.
I have only been told this as a tip. When my RRC pistons had some light rusty marks, I just changed them all.
Brotther's pistons were all fine, other than the typical ingrained rubbery marks.
I kept them all as souvenirs .. most likely could be used on my D2 project if needed.

Handy tip to get opposing pistons out: hold one side in, whilst trying to get the other, opposing side out first!
If you don't do that, and they all come out at the same time, you won't get any out until you push one side back in first!

It's been about 20+ yrs since I'd done opposing piston type calipers, but one of those things I'll never forget to remember.
I'm pretty sure the D1 has the same 4 piston type calipers as the RRC had .. so something to be mindful of.

Another thing with slightly squealy/noisy brakes could be the use/reuse of any backing plate(s) between pistons and pads.
Sometimes flipping this thin plate can help to stop squealing.
Took one of my SD1's back in the day to my mechanic after I replaced pads, and pulled them out again, and refitted them, only to have more squealing.
He took them off and reversed the posi of the thin plate, and squealing stopped!
Made me feel like an idiot. The plates obviously went in one way due to the markings made by the pistons and pad backing surfaces, so that's how I put them back .. the correct way.
So in some cases, putting things in the wrong way can be the better way!

I have found Bendix pads to be noisey, but it could be a caliper seizing and not releasing.
Slotted rotors can also get a build up of brake dust, I had a shudder caused by this, I cleaned the slots and the shudder went away.