[tuatara]

recently put new calipers and pads in a 87 silverado.has been sitting for a while so it took a while to get them to work ok.ive done about 3000miles with no trouble now all of a sudden the front right piston caliper wont retreat so the brakes constantly on.ive pulled it apart and cleaned it out bit no luck.any ideas anyone?

[poncho62]

Caliper is seizing....replace it.
I would replace both front calipers.....chances are the other one is pretty rusty too

While you are at it, I would replace the flex hoses....They are old and may be deteriorating.

[tuatara]

thanks but both front calipers are brand new out of the box.thats whats got me stumped.and only one side is locking up.

[poncho62]

Chances are that one of the flex hoses has debris in it, causing it to act like one way valve, not letting the fluid flow back

[cobalt327]

Originally Posted by tuatara

thanks but both front calipers are brand new out of the box.thats whats got me stumped.and only one side is locking up.

One thing you can check (I've had this happen on a Blazer) is if you live in an area where the roads are salted (and sometimes in other areas) the bracket that retains the flexible brake hose on the bottom A-arm (or where ever it may be at) can rust on the ID of the bracket enough to actually pinch off the hose. This allows the brake to apply but keeps the fluid from returning to the master cylinder so the brake will drag.

I've also heard of the flex hose delaminating on the inside and blocking the flow.

[69 widetrack]

Did you lubricate the caliper sliders? Where the new caliper's off shore rebuilds or a quality rebuild. A rebuilt caliper is exactly that...they needed to be rebuilt because they where faulty for whatever reason. If the caliper cylinder was damaged before rebuilding it may work for a while but will eventually fail. Many jobbers now sell more white box (cheap) rebuilds and in some cases that's exactly what they are.

Ray

[tuatara]

thanks mate.think it's the master cylinder now.it's back feeding into the reservoir.cheers.

[tuatara]

thanks mate.ive pulled all the hoses off and blown them out with air.it now looks like the master cylinder has shat itself.getting blow back into the reservoir instead of feeding down the hose.gonna leave it till the new year now.shops have pretty much shut for the year down under.

[S10xGN]

You may be seeing your compensating ports in action. Look

here on Youtube

here on Youtube

. My guess is dirty fluid, I had this exact same problem with my '98 Dakota while on a road trip. Had to have a mechanic look at it, he disassembled the caliper and couldn't find anything wrong, but did say the fluid was awfully dirty. I flushed 2 QTs through my system when I got home and it's been fine since.

Russ

[tuatara]

thanks for that mate.fluid was completely replaced when we replaced all front and back brakes.pretty confident now that its the master.have a good xmas.andy.

[poncho62]

Good luck...but I cant see how a bad MC could make one caliper lock up and not the other