Handbrake Lever Not Operating On New Rear Calliper

[kester]

Old rear calliper seemed to be retracting piston after releasing brake pedal, and then seemed to leak fluid.

 

Bought new £48 calliper from eBay and whilst footbreak eventually improved after numerous bleeding, handbrake lever on back of calliper doesn't operate the pads at all, even with cable disconnected.

 

Does this sound like a faulty calliper, or is there a way of making the handbrake lever work again?

 

Cheers

[sparky Paul]

Sounds like caliper has not self adjusted. With the handbrake cable removed or slackened, pump the footbrake several times to make sure that the adjuster takes up. Then reattach the handbrake cable and adjust the cable equaliser to take up any slack.

 

If that doesn't work, a faulty caliper is a possibility, or maybe the internal adjuster screw is jammed at the end of travel. You could try manually winding the caliper piston out a little, then repeating the self adjustment procedure.

 

Do you have excessive footbrake travel?

[kester]

thanks for your advice, sorry for delayed reply.

 

1. it seems unlikely that the new caliper is faulty, and when I first installed it the handbrake was working. It was only after multiple bleedings, drivings & screwing the piston back in, and that it stopped operating.

2. there is not excessive travel, BUT there is a little travel, and on very light braking that side is squealing slightly (which I think in this case is a sign of the pads not properly gripping the disc, as squealing stops when you press brake a little harder).

3. I thought the self adjusting mechanism worked if you stomped on brake even with the handbrake connected? But i shall try disconnecting the cable and adjusting once again.

4. i think the most likely is that the internal adjusting is jammed, I'm just not sure how to solve that. When you say winding the piston out, you mean i have to do it manually, I cant just push it out by operating the footbrake?

 

I may resort to taking the old caliper apart to get my head around how it operates/self adjusts, as that might give me more of an idea, and see if i could replace the seal that was leaking the fluid originally.

 

thanks again for your helpful advice!

[BrianH]

They generally on the rear calipers will wind in one way and out the other. Unlike the fronts that will just push back in. Hence you need a tool to twist as well as push them back - Like this > https://www.amazon.co.uk/AllRight-Brake-Caliper-Rewind-Piston-x/dp/B0177MQ4B2/

 

You may find taking the caliper off and using something to twist the piston around to be enough to sort it. I've found its more reliable to use a tool such as the one above that will locate into the cutouts on the piston to rewind the calipers as you know they are going in square then as well.

 

If your having that much grief on the one side i'd consider looking at the flexi hose at the same time, as the footbrake is used to operate the adjustment automatically if this is partially blocked (where it goes though the brackets that retain it this can be the case due to corrosion) then replacing it may help. Operating the caliper should tell you if its working or not with some assistance from someone else to operate the pedal.

Edited May 8, 2017 by BrianH

[kester]

Thank you for your reply. Yes I have the retracting tool and have been working on these for many years, and have successfully replaced rear calipers before.

 

However good point about the rear flexi hose potentially being duff.

 

But the main concern is that even when I operate the lever on back of calliper by hand, the piston does not move. Therefore I'm sure it must have either broken or the internal adjuster got stuck.

 

I'll try winding in and out sgain and see if that helps. And see if the slight travel in pedal is due to requiring bleeding yet again.

 

Cheers

[BrianH]

Thank you for your reply. Yes I have the retracting tool and have been working on these for many years, and have successfully replaced rear calipers before.

 

However good point about the rear flexi hose potentially being duff.

 

But the main concern is that even when I operate the lever on back of calliper by hand, the piston does not move. Therefore I'm sure it must have either broken or the internal adjuster got stuck.

 

I'll try winding in and out sgain and see if that helps. And see if the slight travel in pedal is due to requiring bleeding yet again.

 

Cheers

 

It does sound that way - i'd be tempted to take the caliper off and see if you can get the piston to operate like that - if it doesn't move then it may be the hose. i'd suspect if its sat on the fully retracted position that the handbrake mechanism may not be able to operate, but you'd have taken it off fully retracted by operating the footbrake normally. It may just be a duff caliper, was it a recon one you've fitted or a new unit?

[kester]

The piston definitely moves when the brake pedal is pressed. If the hose was duff (or I have squashed it too much when using mole grips on the rubber when replacing the caliper!) then presume it wouldn't operate properly at all? Equally, the lever on back of caliper is independent of the hose/upstream fluid, I presume, so as the lever doesn't operate the piston, then it must either be faulty or stuck internal adjustment. 

 

It worked for the first few hours/days, so either it broke during bleeding (cant see why it should) or is just stuck. 

 

The caliper I purchased is new but unbranded: http://www.ebay.co.uk/itm/161092135293?_trksid=p2057872.m2749.l2648&ssPageName=STRK%3AMEBIDX%3AIT with only 30 days warranty, so I need to try and have a go this weekend (if I can find any time between ferrying multiple kids about when it is not raining here in Wales!)

 

cheers

[BrianH]

The piston definitely moves when the brake pedal is pressed. If the hose was duff (or I have squashed it too much when using mole grips on the rubber when replacing the caliper!) then presume it wouldn't operate properly at all? Equally, the lever on back of caliper is independent of the hose/upstream fluid, I presume, so as the lever doesn't operate the piston, then it must either be faulty or stuck internal adjustment. 

 

It worked for the first few hours/days, so either it broke during bleeding (cant see why it should) or is just stuck. 

 

The caliper I purchased is new but unbranded: http://www.ebay.co.uk/itm/161092135293?_trksid=p2057872.m2749.l2648&ssPageName=STRK%3AMEBIDX%3AIT with only 30 days warranty, so I need to try and have a go this weekend (if I can find any time between ferrying multiple kids about when it is not raining here in Wales!)

 

cheers

Most likely symptom with the hose is the caliper sticking in the out position and failing to retract, so doubtful its that. It sounds like its knackered to me. Are they in a green box by any chance? If so I'd suspect they are the same ones I brought to replace mine. They have been fine for about 70k miles without any messing about so should be ok.

 

TBH if its playing up given its the brakes involved I'd send it back if I were you.

[kester]

Apologies for delayed reply. Problem was a loose nut on back of handbrake lever on the calliper. The splines were not engaging, hence why it had originally worked, and then failed as the nut worked loose. I'd not thought to check this on fitting, assumed it'd be tight when supplied.

 

It seems to be holding for now, and if it works loose again I'll return it, or more likely try thread lock.

 

(Now all that's left is play in driveshaft and steering rack, clutch slave cylinder, cambelt, and minor oil leak spraying oil everywhere around the turbo area! Any ideals on the last one? Assume unlikely to be turbo seals themselves, but possibly loose/worn pipe from intercooler - I've had to bodge the pipe at the intercooler connection with a screw as the metal locking clip was weak)?

 

Cheers

[BrianH]

Apologies for delayed reply. Problem was a loose nut on back of handbrake lever on the calliper. The splines were not engaging, hence why it had originally worked, and then failed as the nut worked loose. I'd not thought to check this on fitting, assumed it'd be tight when supplied.

 

It seems to be holding for now, and if it works loose again I'll return it, or more likely try thread lock.

 

(Now all that's left is play in driveshaft and steering rack, clutch slave cylinder, cambelt, and minor oil leak spraying oil everywhere around the turbo area! Any ideals on the last one? Assume unlikely to be turbo seals themselves, but possibly loose/worn pipe from intercooler - I've had to bodge the pipe at the intercooler connection with a screw as the metal locking clip was weak)?

 

Cheers

Ah that would explain it good to know just in case it crops up again!

 

No idea on the turbo as i don't have one to look at, Can't you use a jubilee clip rather than a screw to "bodge" it together? To me there shouldn't be oil in the intercooler if all is working well, but on older engines its hardly unusual. Theres loads of diesel owners on here so hopefully one of them will be able to assist though. new topic for that might be your best bet though since its nothing to do with the brakes now.