Front brakes locked
Asked by mr318 Jun 19, 2019 at 01:57 PM about the 1994 GMC Sierra 1500 C1500 SL Standard Cab LB
Question type: Maintenance & Repair
I have a 1994 GMC Sierra 1500 pu with locked front brakes. Vehicle wont move
at all while in gear or neutral. Break pads and rotors are only one year old.
Could it be a problem with the Master cylinder?
2 Answers
Hornet_2497 answered 5 years ago
If it were the master cylinder, all four wheels would be locked up. It is probably the two front calipers seized up. When you replace pads and rotors, you are compressing the caliper piston way back where rust has now formed, jamming it in the bore. While replacing the calipers, it would be a good idea to replace those old brake hoses while it's apart. They can shrink shut, preventing the caliper to release.
I had a problem with my calipers on a 1994 Sierra C1500 releasing and found the problem to be the flexible brake hose connected to the caliper. Seems they have "fingers" inside that can stiffen over time and prevent fluid from returning to the master cylinder.