What to do with my siezed front caliper ????

[Graham]

Hello all,

Carry on from my earlier admittance that I have a passenger side, siezed front caliper.
Time now to sort it out.

Mr. T. wants £269 for a new caliper.
What are my options ?

Graham

 

[Nuclear Chicken]

In reality get a new one from Ian R. Refurbing will be a short term fix. There is a fundamental flaw with the originals and no amount of refurbing will resolve it. Been there, done that and bought the calipers.

 

[Crispin]

What seizes? One of pistons? Why can it not be freed and new seals and bits and bobs be replaced? Do they differ mechanically?

 

[Nuclear Chicken]

Yes the pistons seize 'cause the original rubber boot is crap and doesn't protect it properly. The new one has a new seal arrangement that is mechanically clamped on with stainless steel rings. The old boot had nothing other than the tension in the rubber holding it in place. If you free the piston it will eventually seize again as they move so little as the pads wear. Other than accommodating the new clamping ring, the new caliper looks pretty much like the old one.

 

[Graham]

What seizes? One of pistons? Why can it not be freed and new seals and bits and bobs be replaced? Do they differ mechanically?

Hi Crispin,

Yes, in the front calipers, there are 4 pistons.
One of the pistons has stuck solid on the passenger side, lower inboard piston.

I don't know if to advise my mechanic, to push the piston in, and gently clean the bore of the offending piston, then try to take the piston out.
I have all the seals etc, for a fix.

or should I ask him to use the power of the brake system to force out the offending piston, by taking the caliper away from the disc, and blocking the 3 good pistons from moving out of their bores, and only allow the bad one to attempt to exit ?

If that makes sense.

I have the full repair kit for all 4 pistons on each front wheel.

Graham

 

[24Seven]

I had a siezed piston 2.5 years ago, a large bar and force in situ un-freed it and I'm still using it now, last change of pads and still fine...food for thought

 

[Chris]

....or should I ask him to use the power of the brake system to force out the offending piston, by taking the caliper away from the disc, and blocking the 3 good pistons from moving out of their bores, and only allow the bad one to attempt to exit ?

Yep. That's the one. Plenty red grease after a clean up and re build. Don't try to rotate them out. The seal wrinkles up and jams them solid.

C

 

[Blues]

I tried to pump out one of the pistons with the caliper still on the car using the pads to block the others. I put some serious pressure on the brake pedal with no movement on the piston. Took a 4' pry bar to get it moving.
When I eventually got it out there was some deep pitting on the surface which would have destroyed any new seals. I plan to rebuild them with 316 stainless pistons(if I ever get the time!)

 

[Crispin]

hmmm, I think I have the same issue then. I have a slight yaw (sometimes, not so slight ) to the right when I brake hard.... Odd thing about it though, it comes and goes.

 

[Jon Wildsmith]

hmmm, I think I have the same issue then. I have a slight yaw (sometimes, not so slight ) to the right when I brake hard.... Odd thing about it though, it comes and goes.

Now would be a good time to fix it then before it decides to be a real PITA to free up

The designs I have seen have a clip holding the rubber boot to the caliper and a slot on the piston the boot sits into but no clip that end, that's what's used on the 80 & 100 calipers. That works fine till the boot comes into contact with some sort of reactant e.g. WD40, degreaser, copper ease etc which the rubber doesn't like and it expands, goes like paper and lets moisture and dirt in.

 

[Graham]

OK guys, thanks for the replies.

Today I bought a factory exchange caliper.
A pair of front discs
A pair of rear discs
And new pads all round.

The 120 has brakes again.

Its back to a pleasure to use the brakes, and no weaving, or grinding.

Caliper is £106 exchange, and has the new seals, and new clips
The front discs were £33 each
The rears were £26.00 each
The set of 4 wheel pads were about £38 if I remember, I bought these a good few weeks ago.

I have available a full set of seals for both front calipers. Thats 8 sets of seals etc.
The 2 kits include the new style seals and clips.

Unopened, and of course, unused.
I will put them in 'For Sale Classified' with a price.

Graham

Graham

 

[Crispin]

Agreed Jon - I'll stop procrastinating tomorrow on these things

£106 eh Graham - not bad considering there is no PE involved. I like that idea....

edit:
Graham - that kit, is it OEM or not?

 

[Trevor]

Have you got the supplier details? At that price I think I'll do a replacement of my two fronts instead of the refurb.

 

[Crispin]

I called Mr-T today and asked about the seal kit. £78 excl. Our local Mr-Ian was far far less. Kit is for two calipers so...Depends on how you value your time...

 

[Graham]

If any one wants to buy the 2 seal kits I have,
£50 and they are yours.

Graham

 

[Crispin]

edit:
Graham - that kit, is it OEM or not?

 

[24Seven]

Have you got the supplier details? At that price I think I'll do a replacement of my two fronts instead of the refurb.

Looking at the prices I guess from here http://www.brakeparts.co.uk/