Brakes get stuck

[Daniel Rivera]

Hi,

just recently bought a 2004 Yukon SLT, replaced rear rotors, calipers and brake pads as soon as I got it. Brake lines seem fine.

When I step on the brakes hard they get stuck to the floor and lock up my wheels, they will only release themselves when the car comes to a complete stop. I am thinking maybe faulty abs module?

also the dashboard instrument cluster is stuck in language selection setting.

Any ideas on this. I am new to the forum and tried to use the search option without much luck.

thanks!

 

[wjburken]

Hi,

just recently bought a 2004 Yukon SLT, replaced rear rotors, calipers and brake pads as soon as I got it. Brake lines seem fine.

When I step on the brakes hard they get stuck to the floor and lock up my wheels, they will only release themselves when the car comes to a complete stop. I am thinking maybe faulty abs module?

also the dashboard instrument cluster is stuck in language selection setting.

Any ideas on this. I am new to the forum and tried to use the search option without much luck.

thanks!

Welcome to the forum from Iowa!

A lot of helpful folks here. Unfortunately, I don’t have much experience with the brakes on your vintage vehicle, but there are a lot of folks here who do.

 

[Scottydoggs]

is it both back wheels or just one?

 

[Daniel Rivera]

is it both back wheels or just one?

I feel like it’s all 4 wheels, it gets stuck all the way down like if I were forcefully pressing it down.

 

[Scottydoggs]

I feel like it’s all 4 wheels, it gets stuck all the way down like if I were forcefully pressing it down.

was it doing this before the brake job?

 

[Daniel Rivera]

was it doing this before the brake job?

I don’t know.

I can drive it regularly and the brakes are just fine. This happens only when aggressively braking. I did not try that before the brake job, just saw some corrosion on the rotors and calipers and decided to change them.

After the pedal gets stuck and the car comes to a complete stop they release themselves and then work just fine....until you slam them again.

I live in Michigan and the temp here has been less than zero, that should not matter but just thought I should mention it.

 

[Mechanic421]

I don’t know.

I can drive it regularly and the brakes are just fine. This happens only when aggressively braking. I did not try that before the brake job, just saw some corrosion on the rotors and calipers and decided to change them.

After the pedal gets stuck and the car comes to a complete stop they release themselves and then work just fine....until you slam them again.

I live in Michigan and the temp here has been less than zero, that should not matter but just thought I should mention it.

So my truck did the same thing,I replaced the master cylinder and has not done it sense.

 

[afpj]

Also, "carefully" check your flex brake hoses at the 4 corners, and the center one on the rear depending on setup. I seem to recall something similar happening to another member and turned out the flexible hoses were very worn, breaking down, not holding pressure very well. Just because they look sort of okay on the outside does not mean they don't have cracks and a pseudoaneurism type process happening on the inside. Remember your rig is 16 years old and probably over 100,000 mi so rubber breaks down.

 

[Doubeleive]

I would suspect the master cylinder, there is really no other way for the pedal to "get stuck" the brakes do not apply vacuum to the lines and suck the pedal in, pressure goes the opposite direction

 

[Mechanic421]

My truck is hydroboost. By the way.

 

[Fless]

Before you replace parts, check to make sure the caliper slides are allowing the calipers to slide back and forth (that can help release the brake pad from the rotor). Make sure the calipers and bracket bolts are torqued to specs. It would be helpful to know if it's just one brake, or both on the rear and/or front axles.

 

[Doubeleive]

I can pretty much assure you if the brakes are working when the pedal is stuck down, then it's the master cylinder/booster, bad check valve or something of that nature.

 

[Daniel Rivera]

Thanks guys, I will check that out and let you know how it went.

 

[exp500]

Hydroboost is a whole nother ball game- alot of really bad "advice" usually. If you don't have the factory service manual- GET IT. Really, without any diagnostics, all you can do is flush the brake/power steering system or throw alot of expensive parts at it and still not have brakes that work right. You could go to "diesel place" forums and find your system there as most are hydroboost. Check your build codes in glove compartment. Personally, I have never had to replace a hydroboost master booster. Master cylinders yes, and many times adjust the actuator rod if master cyl replaced.

 

[exp500]

OOps, noticed OP didn't specify hydroboost. Could it be an ABS bleeding/ lock issue? As in abs doesn't release till stopped?

 

[Daniel Rivera]

I don’t know if it has hydroboost. I bought it off the dealer, it was a trade in, so I took it back to them told them to check the master cylinder for me and get it replaced if it was in fact bad.

how can I know if it is the ABS or the master cylinder?

 

[rockola1971]

I don’t know if it has hydroboost. I bought it off the dealer, it was a trade in, so I took it back to them told them to check the master cylinder for me and get it replaced if it was in fact bad.

how can I know if it is the ABS or the master cylinder?

A stand vacuum brake booster is large diameter (about 12") and is a circle behind the master cylinder. A hydraboost unit isnt a big circle and has hoses running to it that are threaded into the unit. (hydraboost uses hydraulic pressure from your power steering pump). If your ABS was the culprit I would suspect that you could hear the ABS pump engage and the brake pedal would pulsate some. If the piston in your master cylinder has a seal hanging up in its bore then you would get the symptom that you have.

 

[mijohnst]

Did you grease the rods that bolt the caliper to the brace? They have little rubber boots on them but they can dry out. Also, have you seen any codes pop up?

 

[Daniel Rivera]

Hi Guys,

so the guys at the dealer said they replaced the master cylinder and the problem persisted. They now say they have to replace the HCU (hydraulic control Unit) how does this sound?

 

[rockola1971]

Hi Guys,

so the guys at the dealer said they replaced the master cylinder and the problem persisted. They now say they have to replace the HCU (hydraulic control Unit) how does this sound?

Sounds like you better your wallet out if you are having a dealership fix it!