1.9 Rear Calipers

[johnsimister 10]

I replaced the left rear caliper a couple of years ago, because the bleed nipple had broken off the old one, and the handbrake has never worked well on that side since. Last year it was MOT-critical and I don't think it will pass again.

 

The problem is that the actuating lever moves too far before it presses the pads against the disc, and once it's past the point at which it's at a right-angle to the disc the mechanical advantage lessens. So more pull on the cable produces progressively less movement and pad-squeezing effort.

 

Can the point at which the caliper lever contacts the internal mechanism be adjusted? I've tried winding the piston right in and then pumping the pedal, as you would when replacing the pads, but it's no better. Yet the right rear caliper's handbrake mechanism, which is the car's orginal, works perfectly with very little movement needed from 'rest' before the pads stop the disc from moving.

 

The replacement caliper was a recon job in a Bendix box, although the caliper itself was obviously Girling orginally.

 

All ideas gratefully received. I'd like to fix whatever is wrong inside this caliper rather than buy another recon one, which might end up with the same problem.

 

Thanks

 

John

[DrSarty 90 1 Cars]

Can I just ask if you're positive that {a} you have the correct handbrake cable pair (as I believe one is shorter) and {b} that the cables are in good condition and the handbrake lever, tensioning bolt AND mounts are good?

[Daviewonder 533 3 Cars]

You need to wind out the piston by hand until theres next to no clearence between the disc and pad, this is how you adjust up the rear calipers. Pumping the pedal with the pad in place wont allow the piston to wind out as the notch on the pad stops the piston from turning (adjusting up).

[welshpug 1,645]

that's arse backwards, you pump the pedal to adjust the pad then adjust the handbrake cables.

 

thats what Haynes says.

 

not much more to add to Rich's suggestions, other than to make sure they're decent pads, I found o.e peugeot pads to be brilliant and not expensive at all from Neat Autos.

 

it'll never be as good as a 1.6 though.

Edited September 16, 2010 by welshpug

[Daviewonder 533 3 Cars]

that's arse backwards, you pump the pedal to adjust the pad then adjust the handbrake cables.

 

I've always slackened the cables and adjusted the calipers/piston by hand whilst fitting the pads. I'm pretty crap at explaining stuff, hopefully someone will understand what I mean

[welshpug 1,645]

no need to do that, just pump the pedal

[Daviewonder 533 3 Cars]

Thats the way I've always done it, looks like I've been creating extra work for myself then, no wonder everything takes me twice as long as most people

[johnsimister 10]

Cables, handbrake lever and mounts definitely OK, and exactly as they were (bar cable adjustment) with the old caliper.

 

Maybe I should push the piston back into the caliper as far as it will go, then wind out the adjuster as far as I can while still being able to get the pads in. Would that work? Really I'd like to see inside the caliper lever mechanism to find out how it's meant to work, and figure it out from there. Is the rubber boot removable without destroying it?

 

Thanks for all the quick replies.

 

John

[Miles 331 1 Cars]

Have you got the small cutout in the right position, If there, this needs to go into the nipple on the pad.

[johnsimister 10]

Have you got the small cutout in the right position, If there, this needs to go into the nipple on the pad.

 

Yes, nipple engaged in cutout.

 

What is done inside the caliper when it is reconditioned, apart from obvious seals, piston etc? Is there anything that gets machined in the handbrake mechanism?

 

John

[welshpug 1,645]

typically just strip apart clean and re-assemble, leaving the ratchet assembly alone (situated inside the piston)

[pug_ham 243 3 Cars]

You need to wind out the piston by hand until theres next to no clearence between the disc and pad, this is how you adjust up the rear calipers. Pumping the pedal with the pad in place wont allow the piston to wind out as the notch on the pad stops the piston from turning (adjusting up).

Aren't the rear calipers self adjusting?

 

The clutch / ratchet mech inside the piston should allow it to wind out along the thread without the piston needing to turn, it slips one way but grips the other (to wind it back in).

 

If you have a sticky rear compensator / lazy caliper so it's not getting full pedal force then the handbrake will still be weak imo because the pads won't be in good enough contact with the disc to give high enough readings.

 

What are the rear footbrake readings like?

 

Graham.

[MerlinGTI 3]

Unlikely to be your problem, but the last one I took apart all the concave washers were in wrong (stacked on top of each other rather than opposing!)