brake caliper

[Vincent F.]

the seal or rubber boot around the piston of the caliper is leaking. Is this replacable or is this caliper scrape. they are fairly new.

[Michael G.]

Re: brake caliper

The outer boot is more of a dust shield. You have a problem with the inner piston seals and need to either rebuild or replace that caliper. Check for burrs ar damage to the piston. Mike

[Jim S.]

Re: brake caliper

the seal or rubber boot around the piston of the caliper is leaking. Is this replacable or is this caliper scrape. they are fairly new.

Vincent, they are hardly ever scrap .
It does souund like you need a rebuild though . Were they ever sleeved ?

Jim

[Joe L.]

Re: brake caliper

Vincent, they are hardly ever scrap .
It does souund like you need a rebuild though . Were they ever sleeved ?

Jim

Jim-----


Yes, one way or another most caliper halves are rebuildable. The exception is previously sleeved calipers that have a damaged sleeve. While it is possible to replace a damaged sleeve, the product liability insurance policies of most caliper rebuilders do not permit it.

[Jim S.]

Re: brake caliper

Hi Joe ,

I didn't think you could resleeve one. I never knew it was because of a liability issue though .

The reason I asked him if it had been sleeved was because if that was the case, I was going to suggest he contact the Vendor and see if he could exchange it. He said it was not very old and they usually put a decent warranty on sleeved calipers . Or, sleeve it as part of his rebuild.

Jim

[Vincent F.]

Re: brake caliper

I dont think it was sleeved, have to get it rebuilt, guess from sitting the seal is NG

[Jim S.]

Re: brake caliper

Vincent,

Yes , if it sits a lot the moisture attacks the calliper and corrodes the cylinder and the seal starts to leak. That is why they sleeve them with stainless steel.

You may get away with taking it apart honing out the cylinder and resealing it.

good luck ,

Jim

[Joe L.]

Re: brake caliper

Vincent,

Yes , if it sits a lot the moisture attacks the calliper and corrodes the cylinder and the seal starts to leak. That is why they sleeve them with stainless steel.

You may get away with taking it apart honing out the cylinder and resealing it.

good luck ,

Jim

Jim-----


Honing won't work on these calipers. A honed caliper bore will almost always leak.

[Vincent F.]

Re: brake caliper

cant seem to get the piston out, is there a special tool or trick to this?

[Joe L.]

Re: brake caliper

cant seem to get the piston out, is there a special tool or trick to this?

Vincent-----


There's no special tool I am aware of for removing caliper pistons. I would suspect that your problem is caused by corrosion in the bores. If they won't even move in and out, then I would tap them with a hammer to see if you can free them up. You will need to separate the caliper halves if you have not already done so.

[Michael M.]

Re: brake caliper

Two ways that I have removed caliper pistons from their bores:

1) Remove the outer dust boot and use two small flat head screwdrivers inserted in the outer dust boot channel on the piston to pry them out. Use the screwdrivers on opposite sides of the piston at the same time;

2) Using an air compressor, blow compressed air through the threaded hole where the brake line enters the caliper (or on the caliper half without that hole, any other brake fluid channel hole). You will have to separate the caliper halves and use your fingers to block off any other channels from which the air could escape. This will force the air behind the piston and push it out. You may want to make sure that you put a towel or rag over the pistons as you do not want them flying out and either injuring someone and/or damaging the pistons. Also, I would recommend emptying as much of the brake fluid out of the caliper as possible before trying this.

Good luck