All 4 brakes locking up help?

[o1supra]

Hi new to this forum here the story I have a 91 teg GS all 4 of my brakes are locking up its being over pressurized. I replaced the brake power booster but still no change after about 15 -20 min the brakes become hard and the car will nolonger roll because the brakes are on i have to remove the air hose from the booster to relive the pressure to free up the brakes anyone have any ideas why this is happening????

 

[Samurai_Blue]

vacume ?

 

[scubajosh12]

did you replace the master cylinder with the vacuum booster.

 

[o1supra]

I replaced the master less than 6 months ago. replaced the booster 2wks ago

 

[scubajosh12]

have you tried unplugging your abs module. i know a light will come on but if your abs system has a fault it could cause that also. have you recently done the brakes

 

[SbS91TeG]

Most abs system faults will default to base brakes no abs function this sounds like a sticking caliper piston or slide points were not lubed correctly if brakes were changed

 

[o1supra]

No brakes were changed when this first happened but i did check all the calipers and found the rear drivers side was seized up replaced it and bled the lines for air but its still happening. ive even unplugged the abs. ? This has me stumped

 

[SbS91TeG]

Most base brake systems in fwd is a split diagnoal which is not farthest from master cyl first to closest to master cyl like rwd.

I believe its driver rear, pass front, pass rear, driver front in fwd vehicles and pass rear, driver rear, pass front driver front in rwd vehicles. And this is if its a non abs system, abs system have special bleeding procedures.