Front caliper rebuild?

[Reeve]

When I got my speed it always pulled hard to one side when I hit the front brakes. I gave bleeding a try and it seemed to help some but still did not fix the problem. ( I did read up on bleeding the brakes before I did it) I finally just pulled the caliper and took it apart. It was not stuck but the piston shows some minor pitting and has one scratch that almost looks like a factory mark on it but nowhere where near where the seals ride. I don't really know what to do. I never saw any fluid leaking from the caliper. Is a bit of pitting normal on these? Should I just clean it up and try it or can I get new seals and a new piston for it? Thanks.

[wistech]

If its pulling to the right while braking then the left caliper would be the culprit. You could maybe rebuild them the rebuild kits might be more than a good caliper. One thing to make sure is good is the pin slides.

[Reeve]

I checked to make sure the pins were free before I pulled it. The way I checked it was locking the brakes on and trying to turn each tire. One was locked solid and the other I could get to turn.

[wistech]

If you can turn a tire with the parking brake on then either the line is plugged or you have way too much air in the system. Does it build up pressure?

[MX Quad Dad]

you should do a test spin of each tire with the brake off. if you have a brake dragging then thats where you problem is

another thing you can do is ride for a few miniuts, then check the temp. of each rotor

[speedracer]

QUOTE (MX Quad Dad @ Nov 8 2010, 06:06 PM) <{POST_SNAPBACK}>

you should do a test spin of each tire with the brake off. if you have a brake dragging then thats where you problem is

another thing you can do is ride for a few miniuts, then check the temp. of each rotor

Good tip, thats how I found out my carrier was bad. I got a stick stuck under the swingarm skid, braced myself on the axle to pull it out and it was BLAZING hot, I am surprised it wasn't glowing, melted part of my riding glove!

[Reeve]

Well I polished up the piston and put it back together. I never had any brake drag just one that didn't brake well. I bled both sides and now they have even pressure but both will turn with the parking brake on. It looks like I will need to do some more bleeding to get all the air out.

[cannondale27]

Set the parking brake and check it in the morning.That gets alot of little air out.If it still doesnt brake well check wheelbearings and for bent spindle.

[SlOoT]

Air in the brake system can not be the cause of one side braking better then the other, that is impossible coz the pressure is the same in the whole system. There is only one main master brake pump and both callipers are connected to the same hose/system.

Bad braking on one side could have these causes:

-Dirt, oil or grease on disc and/or brake pads.
-Burnt/glazed brake pads.
-Bent disc.
-Stuck piston in caliper.
-Floating system(pins) in caliper is stuck.

I worked on one today that had that problem. Caliper was leaking resulting in oil on the the disc and pads... Somehow a rock got in there and did some damage. Disc was also bend. I rebuild the caliper, replaced disc and new brake pads, problem solved.

A fast way to get air out is to remove caliper from spindle, pump a few times so piston moves out and then push it back al the way. That way all the air went out in one try when I worked on one today.
And then just bleed the normal way once to get the last bit out. I had the braked back to normal in 30 seconds with that method.

[cannondale27]

Sloot you are right if air anywhere it would effect all brakes in system equally.I have seen bad bearings mess up braking on one though.Does same as a bent disc.