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Would someone be so kind as to help me out with my latest task?

Simply, I need to swap out a faulty caliper for a replacement one.

i have the faulty caliper ready come off but don't want to end up having to completely refill the brake fluid. i assume i can somehow clamp the brake line, fit the caliper and then bleed out any air - is this right?

Many thanks,

Dan

Hi Dan

You need a brake hose clamp like this https://www.machinemart.co.uk/shop/prod ... -clamp-set Halfords sell them singly

You clamp the brakeline with that, remove from the caliper, fit to the new caliper, open the bleed valve then release the clamp and rebleed just that caliper and all will be fine

If its a rear caliper it is VITAL you do NOT move the handbrake mechanism until the caliper is in place, with pads fitted against the disk and the brake pedal is firm or the mechanism will be damaged.

alexperkins wrote:Hi Dan

You need a brake hose clamp like this https://www.machinemart.co.uk/shop/prod ... -clamp-set Halfords sell them singly

You clamp the brakeline with that, remove from the caliper, fit to the new caliper, open the bleed valve then release the clamp and rebleed just that caliper and all will be fine

If its a rear caliper it is VITAL you do NOT move the handbrake mechanism until the caliper is in place, with pads fitted against the disk and the brake pedal is firm or the mechanism will be damaged.

Thanks Alex, really appreciate your help.

Novice question - what's the process for rebleeding the caliper after fitting, is it simply just opening the bleed valve and pressing the brake pedal till clean, airless fluid emerges?

P.S. it's a front caliper

Correct - ideally a two person job, or use a pressure bleeder otherwise its very easy to get an air lock

alexperkins wrote:Correct - ideally a two person job, or use a pressure bleeder otherwise its very easy to get an air lock

Thanks Alex - I'll report back with my disaster / success story

PS what size spanner is the bleed nipple??

Just a quick one - someone mentioned they be a washer, on the connection between the brake line and the caliper, that would need replacing. is this right?

also what type of connection is this? push on with a retaining nut / botl??

Thats a copper washer - its non removable - its pressed onto the hose.

Its a threaded line that screws into the caliper. Just dont overtighten it - sometimes, some PTFE around the thread can help.

I've received a recovered caliper but having an issue trying to figure out the best way to fit it -



it's detached from the donor car at the union between the metal brake line and the rubberized hose, with the union between the caliper body and the rubberized hose being highly corroded.

Clearly for me it is best to fit the caliper at the union between rubber and metal lines - but this means i will not be able to clamp the hose shut when fitting - can i just swap them over quickly without air being sucked into the entire system, ideally i only want to be bleeding the newly fitted caliper.

Thanks,

Dan

That caliper is a state!!

I would be tempted to fully refurb it before fitting - ie piston out, check the seal, replace the hose, paint the caliper, free up the bleed nipple.

You also dont know how long its been detached from a car for - its possible the inside of the piston is corroded depending on how much brake fluid is left in it - definately needs checking over.

You can put a piece of clingfilm under the brake master cylinder cap to prevent fluid coming out which works quite well, but you may have to rebleed both front brakes

alexperkins wrote:That caliper is a state!!

I would be tempted to fully refurb it before fitting - ie piston out, check the seal, replace the hose, paint the caliper, free up the bleed nipple.

You also dont know how long its been detached from a car for - its possible the inside of the piston is corroded depending on how much brake fluid is left in it - definately needs checking over.

You can put a piece of clingfilm under the brake master cylinder cap to prevent fluid coming out which works quite well, but you may have to rebleed both front brakes

i know tell me about it, my plan was to run the salvaged one whilst i refurb mine.

i'm gong to whack this one on a see how it goes, get mine refurb'd and put them back on.

how hard is the union between rubber hose and metal line to undo?

Soak it all in penetrating fluid before even attempting to undo it

You'll need to use a brake hose spanner too so you don't round the nuts

alexperkins wrote:Soak it all in penetrating fluid before even attempting to undo it

You'll need to use a brake hose spanner too so you don't round the nuts

is it a 10mm nut?

thanks for the help, Alex

11mm

Halfords sell the special spanner

alexperkins wrote:11mm

Halfords sell the special spanner

Top man, thanks

Got it on fine (after sprucing it up, a lot!) - tested it by pumping it out and winding it back and it was surprisingly smooth.

Brakes are still hotter than i would like but i'm going to monitor them before looking at other causes - would VCDS show anything? not that i can use it anymore anyway