Rear cliper ( caliper even ! ) leak

stina

stina

New Member
Hi all .
I have noticed the occasional spot on the garage floor under the diff . It is brake fluid , crawled under yesterday afternon for a look , and it's coming from the right caliper . Not a great deal just a drip once or twice a week . The calipers were rebuilt in 03 when the car was restored ( Annabells in Derby got receipts for thousands ! ) She has only done 6k miles since , 1600 with me this year . I'm guessing lack of use has contributed to their failure . The pads are still like new and the brakes are good and strong . I do realize i need to sort the problem out soon though ( especially as mot in Feb )
I know the reputation of the rear calipers and am wondering if this is a job i can tackle myself ? I've sorted brake caliper , drum , disc issues on lesser cars , but the p6 is a bit daunting ( or is it ? )
I don't want to get into a long , drawn out , expensive rebuild if i can avoid it as the brakes , hand brake included are very strong . I would like to sort the leak ( piston seals i guess ? ) and renew the fluid .
I have read through loads of old brake threads on the forum to try to get acquainted with the system , and possible problems .
Any advice on the best way to remove the caliper , reseal the piston , special tools , where to source parts required etc much appreciated .
I took a pic while i was under there .
Cheers stina
 

Attachments

  • caliper 005.jpg
    caliper 005.jpg
    43.7 KB · Views: 1,613
Re: Rear cliper leak

The key thing is not to attempt to repair the caliper on the car. The combination of difficult access and intricacy makes it pretty impossible! To get the caliper off, I would have no hesitation in removing driveshaft complete, then disc. Then you have a chnce of getting to everything else. There's a full write up at the start of the section.

Chris
 
Re: Rear cliper leak

Hi Stina,

That is rather disappointing to have a leak in such a short space of time even with lack of use. If the bores have been resleeved in stainless then that is at least one expence that you won't have to cover again.

Seeing how handy you are doing the job won't be a problem for you, but the only sticking point might be undoing and ultimately refitting the halfshafts along with applying the correct torque of 85lbs/ft. That is pretty tight so you might need someone to lean on the torque wrench for you, but in any case, where there is a will there is a way!

Oh, you'll probably find that the metal can with the rubber seal around the base is filling up with fluid with a corresponding drop in the reservoir level.

Ron.
 
Re: Rear cliper leak

It's not as daunting as it sounds. Removing the rear brakes was one of the first jobs I did on my P6. If you have a workshop manual, it really helps. It makes much more sense when you see how it's all supposed to come apart. I don't think I followed the optimum process. I found I was raising and lowering the diff a few times to gain access to bolts. You need to find out why the calliper is leaking. I found the cylinders were pitted. This was beyond me to fix, so I had to send them off to be resleeved. Out of interest though, I'd stripped and reassembled the caliper just to see how it went together. Again, not as daunting as it sounds. Get stuck in, it's really not that difficult, just a bit harder to get to than normal brakes.

Tom
 
Re: Rear cliper leak

O.k guys , so the way to go is remove the drive shaft and disk then . Can i do/remove just the one caliper ? Where best to get hold of a repair kit and what do they contain , what else am i likely to need ?
I have a work shop manual so that'll help . Thinking of having a go in the next couple of weeks , so stand by for loads of questions ! :roll:
 
Re: Rear cliper leak

Yes, you can remove the one caliper but I would be tempted to do both of them as Sod will enforce his law & set the other one leaking when you have reconned & refitted this one.
Your choice but removing two will be only marginally more work than removing one. If they haven't been resleeved in stainless (very likely), then it will pay dividends to have them done, even if the bores are good.
 
Re: Rear cliper leak

I have just done mine last weekend, after about 4 years. In the first place the cylinder bores were not perfect, so i knew that they would not last for long. This time i had the calipers sleeved in stainless (120 euros for the pair, not too bad), so they will be better. The usual repair kits that you will find in the usual suppliers are just rubber seals and O rings, but if the parts inside the caliper are not worn out, this kit is enough.
I wouldn't say that it is a difficult job, but it is involving and you have to take your time. If you read through the relative posts in here you will understand. The job is much more easier if you can use a pit. Otherwise, raise the back of the car as far as it will go safely. It will make working under the car more comfortable. Also if you remove driveshafts and discs as suggested by others, you will find that there is quite a lot of space to work around the calipers in order to remove them. Don't attempt to remove the interconnecting hose with the calipers in the car, it is much more easier to pass one of them over the diff and take them out of the car as a connected pair.
 
Re: Rear cliper leak

They are not so bad.

I remove both calipers, it makes it easier as the hoses are not easy parted.

Once you have overhauled them fit hoses and then sling them over the dif and bolt on.

Couple of things to watch. The pin which oprates the hand brake can go missing (the mini missile thing), the hydraulic piston can wear at the tip so check it.

Also even if the hoses were changed replace them when you are there rather than a few years time.

Check the ratchet works before rebuild.

Colin
 
Re: Rear cliper leak

Hi Stina.
I have just carried out this job...and had never done any of this type of work before.
Initially, my idea was to just have a bit of a check and clean up...the bare minimum.
But to be honest, its a cheats way out.
To really get to these things means driveshaft disconnection at the discs and then disc removal.
Theres no real point at this stage in doing just one.
Do both and do what is needed to discs, hoses etc.
I can see (after doing it) that this is REALLY one of those jobs that PAYS to do it right.
You know how it is...some jobs you can get away with a half baked effort...this isn't one of them.
The key for me was 3 things.
1) Taking my time.
You just wont get all of it done in one afternoon.
It took me about 4 reassemblies of various things before I understood what things went where and how they worked.
2) Ask heaps of questions here.
Sometimes I just couldn't figure things out...so I got straight onto here and had helps of help to put things right.
3) Had a professional brake shop do the actual calliper rebuild.
Because I did everything but the actual rebuild, it only cost me $200 for outsourced work.
You probably don't need a full rebuild, but at least check over the lot. And this can only be done by a full step by step dismantle.
If I ever need to do the job again, I'm sure it would be a lot quicker no that I am more familiar with the process
 
Re: Rear cliper leak

I'm with Colin. The extra effort to remove both calipers together is more than offset by avoiding the battle you will have to refit the connecting hose in situ.

Chris
 
Re: Rear cliper leak

The bit that caused the most swearing on mine was a close call between undoing the link pipe from the caliper and trying to get the lever back in with the thing on the bench.

I did one of mine and left the disc and all that guff in there. Putting it back in is a million times easier than taking it off, cos you know where everything goes. Taking the disc off would make it about 8 million times easier to undo the big pivot cover plug thing, but it can be done with the disk still there.

have small hands - mine were too big so dad had to do a few of the bits cos i couldn't get my hand in.
 
Re: Rear cliper leak

Stina, the rebuild kits I've had are aftermarket and contain a selection of 'O' rings, a hydraulic-piston seal, a dust cap for the bleed nipple and a dust cover seal. Good luck, the overhaul sticky at the top of this section is thorough.

Tor
 
Re: Rear cliper leak

Hi guys thanks for the advice and encouragement . Will order rebuild kits over the next week and have a go in the next week or two .
 
Re: Rear cliper leak

The cover is missing of the big pivot nut, and why on earth (or how, even) did they manage to put the clevis pin in that way around? Another fine job. Not surprising that you're doing it again really if it's all up (down...) to that standard. The brake pipe/hose bracket on the body is all bent as well..... :?
 
Re: Rear cliper leak

Hi Harvey ,
Thought You'd chime in with a bit of blunt , blind positive ,encouragement sooner or later , thanks for that ! I'm sure i'll struggle , and f**ck up along the way , and things wont be easy , but i'll give it all i've got and keep the old girl on the road some how .
Have a good weekend .
Stina :LOL:
harveyp6 said:
The cover is missing" of" the big pivot nut, and why on earth (or how, even) did they manage to put the clevis pin in that way around? Another fine job. Not surprising that you're doing it again really if it's all up (down...) to that standard. The brake pipe/hose bracket on the body is all bent as well..... :?
Click to expand...
Ps
Two f's in off
 
Re: Rear cliper leak

harveyp6 said:
Not surprising that you're doing it again really if it's all up (down...) to that standard. The brake pipe/hose bracket on the body is all bent as well..... :?
Click to expand...

Blimey Harvey , I thought i was buying a brand new car , someone really tucked me up eh ! , looks like it's nearly 40 years old , good job you pointed that out !
Oh , by the way , that's my pride and joy that i had a great day out in today you're rubbishing ! :LOL:

PM me if you have any more helpful advice , or a free afternoon !I'll make the tea !
Cheers stina
 
Re: Rear cliper leak

stina said:
Two f's in off
Click to expand...

Quite right, my typing's not all it should be. Still, makes a change from the double letters that seem to creep in most of the time for some reason. More haste, less speed I suppose, but that would be boring.
 
Re: Rear cliper leak

All I would say is that there's no reason why you can't do it yourself (no special tools required and plenty of advice here) and when doing so you should be able to do a better job than the one that was done previously, and if that was done by someone who was charging for the job, they should have known better.
 
Re: Rear cliper leak

I'll assume we're still cyber !!! ( can't spell it ) friends then , and go to bed now ! Wanted my rant , but might still need the snippet of info tucked away in your head some day :roll:
 
You must log in or register to reply here.
Back
Top