I've just replaced the near side rear brake caliper as it had seized, the pads were down to the metal. I've put in new pads and bled the system, after taking for a test drive i can hear rubbing whilst driving along, after about 10/15 minutes driving I stopped and felt the discs, both rear were very hot, the two front were fine?

Initially thought maybe i'd reset the handbrake too tight but pretty sure that's not the case as it takes 5 or 6 clicks before the car stops moving on a hill. Also, the brake pedal feels quite spongy, expected it to be a lot sharper following bleeding the system?

Any suggestions on what I should look at please?

thanks

Did you rotate the caliper piston so that the pimple on the back of the pads slots into the recesses in the piston?

The piston looks like an Iron Cross shape when you look at it. The recesses have to be positioned at the "quarter hour" positions so that the pad pimple fits into one of them (the one at 3 o'clock).

To eliminate the hand-brake as the cause, back the lever off using the screw under the rear air-vent or ashtray. If that makes no difference, then it's not the handbrake.

Do both sides get hot, or just the old or new caliper?

Ralf S.

i made sure to line up the pimple on the pads with the piston caliper so not that.

Both discs get hot, i'll go and try the handbrake procedure you've suggested and see if that makes a difference,

thanks for the help

Ralf S. said:

Did you rotate the caliper piston so that the pimple on the back of the pads slots into the recesses in the piston?

The piston looks like an Iron Cross shape when you look at it. The recesses have to be positioned at the "quarter hour" positions so that the pad pimple fits into one of them (the one at 3 o'clock).

To eliminate the hand-brake as the cause, back the lever off using the screw under the rear air-vent or ashtray. If that makes no difference, then it's not the handbrake.

Do both sides get hot, or just the old or new caliper?

Ralf S.

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Not sure if its meant be three oclock position.
On my Multijet - when I did it the other week - it was 12 and 6 oclock position, i made the mistake of putting it all together then noticed the piston wasnt fully sitting against the pad - this was during bleeding the system and watching the piston move - quickly raised the calliper and got the disc grinder removal tool in the two wind back holes and rotated it - it looks like 12 and 6 oclock postions.

tried the handbrake option and no joy, in fact now all 4 discs get very hot after driving around town for about 5/10 minutes...is this normal??

The pistons can only be in the 9/3 o'clock position on mine as that's where the dimple is on the pads. Haven't checked to see if the piston is moving though, would i need to get someone to pump the brakes whilst i watch the pads?

mexnick said:

tried the handbrake option and no joy, in fact now all 4 discs get very hot after driving around town for about 5/10 minutes...is this normal??

The pistons can only be in the 9/3 o'clock position on mine as that's where the dimple is on the pads. Haven't checked to see if the piston is moving though, would i need to get someone to pump the brakes whilst i watch the pads?

Click to expand...

Ok - I might have been looking at it on an angle when I did mine.

When I did mine - i did all 4 and rebuilt each caliper.
I didn't replace anything other than one sliding pin - they where all fine, i just cleaned off the old copper grease and used some proper stuff to lube them up and also lubed up the sliding pin holes.

I used high temp grease (the proper stuff) copper grease is no good for the pins, just the pads and face of the pistons!.

If I was you - I would strip each caliper down and wire brush them, remove the shims and also give these a good clean until they have no dirt on what so ever - i used elbow grease spray and some thin emery tape then polished the shims so they where smooth again - this will help the pads sit nicely and move freely.

Also - emery tape the thin little grooves in the caliper carrier when you have removed the shims - so they fit nice and snug again... it takes a while but you will have piece of mind that they almost new again

Thanks for all that advice, will do that when time permits, I only replaced the one caliper and pads as the rest were working fine. I wanted to replace the pads on the other rear brake but some idiot before me has rounded off the caliper retaining bolt so couldn't get that one off. Will get a mechanics to do that one for me another time as those pads still have plenty of life on them anyway.

What's confusing is that all the discs are now getting hot and I've only messed about with one of the calipers? I have bled the system but am not aware how this could cause all of the pads to bind unless i'm missing something?

I had the same problem about the rubbing on the read left side.
My mechanic found that the gasket (if i can call it that way) that is around the piston was broken. So when i pressed and release the pedal the breakpad wouldn't go back to the original position and it kept, what you call rubbing, the break disk.

Note: my brakepad was down to the metal also. Break disc resurface/rectification was also made.

If all four brakes are binding then the problem is something else (i.e. not the rear caliper, particularly since that was new).

How did you bleed the brakes? Did you use a pressure bleeding doodah (like Eazi-bleed) or did you do it "analogue".. by pumping the pedal while the bleed screw was open, one caliper at a time?

Jack up the car and feel whether the wheels rotate freely. If one is binding, undo the nipple a bit and see if that cures the "bind". If so, there's pressure still in that circuit. It could be a degrading hose. The bleeding may have caused an internal failure (I'm guessing the hoses are the original 10+ years old kit).

If all the wheels are binding, it's unlikely to be a degraded hose, so check the brake pedal:

a) Did you adjust/remove/disturb the brake light switch at all? It could be preventing the brake pedal from going back to where it should.

b) Also check the movement of the brake pedal on the rod it's attached to. I can't remember the setup but the pedal rotates on a shaft and pushes a rod or lever to activate the brakes. Is that all nice and lubed and free moving? The bleeding (if you pumped the pedal) may have jammed or seized something. This would cause binding on all four wheels.

If none of this gives you any joy, then the problem is at the servo or master cylinder.

Servo can be eliminated by loosening the nuts that hold the master cylinder to the servo. Then press and release the brake pedal. If the brakes free up, that's a servo problem (holding the brakes on even without brake "pedal").

If they stay stuck on... you can try releasing one of the brake circuit nuts at the master cylinder. If the brakes release, then the m/c has an internal bind/blockage and is not letting go of the brakes, even without brake pedal.

But.. check the pedal the physical movement/release of the pedal first. It'd be a shame to do all this further tinkering only to find a rag wedged in the brake pedal or something..


Ralf S.

I bled the brakes old fashioned style, one at a time using a bottle and hoses etc. I'll try opening the nipple on the each one as suggested and see what happens.

Didn't mess about with the brake pedal light switch so presumably not a problem there.

appreciate the advice with the servo and m/c, i'll venture into that if no joy with the initial investigation.

Many thanks for the help!

Could be the master cylinder then. If you give the brake pedal repeated long pushes all the way to the floor, the internal O-rings/seals can get dislodged. Best technique is a series of short prods of the brake pedal .. just enough to squirt the next bit of brake fluid through.

If you get a hammer and give the m/cylinder a series of sharp taps as someone is working the brake pedal a bit (no bleeding going on.. just closed system) they can sometimes sort themselves out.

If the pedal slowly drops to the bulkhead when pressure is applied to it, that's usually not a good sign, since it means the seals aren't sealing... which is normally cylinder or seal wear... which needs a rebuild or (most often cheapest and less hassle) replacement.


Ralf S.

tried jacking the car up and spun the rear wheels, the one i replaced the caliper on does make a rubbing sound as the wheel goes round. Should the wheel spin totally silently or is a slight rubbing normal? There's also a fainter rubbing sound on the other wheel too?

It'll make some kind of "smooth" whooshing sound since the pads are always in floating contact with the disc face.

The new one being louder might only be because the sliding pins are more free (I presume you cleaned/lubed them) so the sliding part of the caliper (via the pads) is better able to float.

But when you spin the wheel, it should turn freely ... probably around a complete turn depending on how hard you spin it.

If it's hard to turn the wheel, or it stops after just 90 degrees or so, then the pads are binding. Lever the pads away from the disc a little (use the backing plate "ears" as the pivot, not the pads surface) and spin the wheel again, you'll see a big difference.

It doesn't sound like they're particularly binding though. If they were, you wouldn't be able to "spin" the wheel at all .. it would just move a few inches at a time, unless you're Popeye.

Any steep hills near you? Get to the top and (traffic safety considered) try coasting down in neutral with the windows open. You should be able to feel (and hear) if the beast is dragging it's brakes.

Any smoke and/or intense heat and/or blue discs is usually a bad sign... just normal heat (don't be tempted to touch the disc.. ) is normal for brakes.


Ralf S.

That's reassuring thanks, think I was probably being a bit over cautious, the wheel spins a bit over one revolution so I reckon that's fine,
Thanks again!

Ralf S. said:

It'll make some kind of "smooth" whooshing sound since the pads are always in floating contact with the disc face.

The new one being louder might only be because the sliding pins are more free (I presume you cleaned/lubed them) so the sliding part of the caliper (via the pads) is better able to float.

But when you spin the wheel, it should turn freely ... probably around a complete turn depending on how hard you spin it.

If it's hard to turn the wheel, or it stops after just 90 degrees or so, then the pads are binding. Lever the pads away from the disc a little (use the backing plate "ears" as the pivot, not the pads surface) and spin the wheel again, you'll see a big difference.

It doesn't sound like they're particularly binding though. If they were, you wouldn't be able to "spin" the wheel at all .. it would just move a few inches at a time, unless you're Popeye.

Any steep hills near you? Get to the top and (traffic safety considered) try coasting down in neutral with the windows open. You should be able to feel (and hear) if the beast is dragging it's brakes.

Any smoke and/or intense heat and/or blue discs is usually a bad sign... just normal heat (don't be tempted to touch the disc.. ) is normal for brakes.


Ralf S.

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Yea - i did this (put hand near the rear brakes and they felt warm) so decided to touch the disc - two finger prints burnt off!! - my brakes are not rubbing - i just did some super hard emergency stops to make sure they where working and boyo the fronts smoked for about 30 seconds after... then like an idiot - i thought the rears wouldn't be that hot... i was wrong!

Couldn't use the finger print reader for about a week