Brake Caliper seal replacement

Brian4

Brian4

Zorg Guru (IV)
British Zeds
East Anglian Crew
Joined
Dec 23, 2011
Points
173
Location
Near Grantham
Model of Z
Z3 3.0i Auto
I decided that the front flexi hoses needed replacement and whilst I had it apart I would change the seals on the calipers.I had painted the calipers 2 years ago but some bits were scabby again around the dust seals and the only way to get at these was with the piston out.
Got them all apart easily enough, I used the bike pump and an old tyre valve as an adaptor to fit in the hole for the flexi pipe to force the pistons out.
All cleaned up and seals replaced now, pleased how they have turned out and easy enough to do.

Cleaned up caliper and piston.


All back together.


The pair ready for refitting.
 
Looks good Brian. Where did you source the calliper seals please? How much were they please, if you don't mind me asking?

Tony.:cool:
 
I got them from Brakes International £14 for the seals and £18 for the hoses.
 
That's a good price. I will keep that to memory. Thanks.
 
These lasted until now and knew I should have replaced the pistons at the time.The front had seized on so stripped down again and got the new pistons and now ready to go back together again.Decided against changing the calipers as I didn't feel like painting them again to match the rears as they are all black at the moment.

Comparison if old and new pistons and shows why the pistons rust into the bore of the caliper. Didn't help leaving the car off the road during all this wet but should be good to go again now.As they are fairly new pads and the piston is quite a long way back into the bore the area that rusts is close to the caliper body so if anybody changes their pads and discs they are liable to get sticking brakes as the exposed part of the piston is pushed back into the body of the caliper.

Old and new pistons.

20160210_190630.webp
 
Good Write up Brian, we used to wire brush the pistons down and put high temperature grease on the pistons. Can't say I ever had one seize up again.
Are they stainless steel pistons Brian?

Mike
 
@Brian4 can I ask how much the replacement Pistons cost ? Looks like a good overhaul.
 
Unless your pistons are perfectly clean and rust FREE, change them with the seals or otherwise you're wasting your time and money.

Tony.
 
EnthuZiaZT said:
Good Write up Brian, we used to wire brush the pistons down and put high temperature grease on the pistons. Can't say I ever had one seize up again.
Are they stainless steel pistons Brian?

Mike
Click to expand...
Other Brian here Mike, I believe they are just steel pistons.
 
Never seen stainless calliper pistons, only rusty steel ones. Usually it's the outer dust seal deterioration which starts corrosion on the pistons, if they stay "sealed" they will stay rust free.

Tony.
 
pgunter said:
@Brian4 can I ask how much the replacement Pistons cost ? Looks like a good overhaul.
Click to expand...

The pistons and seals and dust covers were £45.81 delivered from Brakes International ordered Wednesday evening and arrived Monday.

@EnthuZiaZT the pistons are chrome plated steel and look a very good finish


As @t-tony says if the pistons are slightly rusty change them and rubber seals as false economy not to. Will reassemble at the weekend.
 
If you are able to do this job yourself then maybe it's worth taking a chance on a very slightly pitted piston. However if you're paying garage labour rates, which can be very high, then you want the best possible outcome for your money and that means replacing the pistons while the calliper's are stripped.

Tony.
 
I have used stainless Pistons before, it's nice to think that you've mended something and improved on it

Mike
 
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