Brake Repair Needed

mcin0003 · November 30, 2008

I've been replacing all of hte components on my 03 GMC sierra 4x4. The problem started with my front brakes jamming. I've since replaced all of the rotors, calipers and the master cylinder. Everything seemed to be working fine for few weeks but the problem is resurfaceing. Is there some other part control valve or module that needs to be repaired?

Thnks

pennzoil29 · November 30, 2008

You really should introduce yourself before bombarding us with ?'s. You may want to look at the check valve. Welcome to the forum

superjim · November 30, 2008

Please explain in more detail, what JAMMING means.

Does it have ABS?

If it does have ABS... check all the wiring and connectors going to the sensors on the hubs.

Does it have any warning lights on the dash illuminated?

Have you checked the little rubber hoses that go from the metal line to the caliper?

I have had them go bad internally, and a little piece of rubber drops down inside the rubber line and acts like a CHECK VALVE. You can apply the brakes... but they won't release properly.

Oh... BTW... Welcome to the forum.

mcin0003 · November 30, 2008

Please explain in more detail, what JAMMING means.
Does it have ABS?

If it does have ABS... check all the wiring and connectors going to the sensors on the hubs.

Does it have any warning lights on the dash illuminated?

Have you checked the little rubber hoses that go from the metal line to the caliper?

I have had them go bad internally, and a little piece of rubber drops down inside the rubber line and acts like a CHECK VALVE. You can apply the brakes... but they won't release properly.

Oh... BTW... Welcome to the forum.

Thank you for the welcome.

It has ABS but there aren't any warning lights or codes that pop up. The jamming I'm refering to is the caliber is not releasing properly and both the rotor and the pads are heating up and burning. It doesn't happen on al wheels, it just seems to be the front brakes and lately it seems to be the left (drivers) side.

When I look into the engin compartment, just below the master sylinder is a little aluminum block where the brake line and a brake sensor attache. Is this some sort of control block or check valve?

mcin0003

superjim · November 30, 2008

I am a brake mechanic... just relating what fixed some of the problems I have had down thru the years.

If it is just the left drivers side that is binding up... I would first replace the little rubber hose that runs from the metal brake line to the top of the caliper.

If that don't help... then I would check out the silver valve that all of the brake lines connect to... by the master cylinder.

That valve is called (I think) the PROPORTIONING VALVE.

mcin0003 · November 30, 2008

I am a brake mechanic... just relating what fixed some of the problems I have had down thru the years.

If it is just the left drivers side that is binding up... I would first replace the little rubber hose that runs from the metal brake line to the top of the caliper.

If that don't help... then I would check out the silver valve that all of the brake lines connect to... by the master cylinder.

That valve is called (I think) the PROPORTIONING VALVE.

I'll try that.

Thanks.

superjim · November 30, 2008

You may be able to check it out and narrow down your problem....

Jack up the front wheels.. support the truck on stands so it will be safe and stable...

Mash and release the brakes.. then see which wheel turns easy and which one don't.

If one wheel don't want to turn... open the bleeder screw on that caliper.

If it then turns... then SOMETHING is keeping the pressure from releasing and the fluid from going back to the master cylinder.

Mash and release the brakes again... this time loosen the fitting on the rubber line connecting to the caliper. If the wheel now turns.. it is NOT the caliper.

Mash and release the brakes again. This time loosen the fitting where the rubber line connects to the metal line. If it now turns easy... it IS NOT the rubber line. If it still don't want to turn... it IS the rubber line.

To check it a different way....Mash and release the brakes again... this time loosen the fitting where it connects to the valve by the master cylinder. If it still don't want to turn... it is the rubber line.

If all of these checks allow the wheel to turn easy... it is probably the valve.

This way you can narrow down WHERE the malfunction is.