My brakes keep locking up until I disconnect the booster

Tiny
AJTHECARDOC
  • 2002 HYUNDAI SONATA
  • 125,000 MILES

I have a 2002 Hyundai sonata 2.4 no abs. I drive about 5 miles and brakes lock up. I disconnect hose from booster and it release brakes. I replaced booster with a used one and it did the same thing. I inspect master cylinder and no fluid leak at master be I replaced power brake booster

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Monday, October 10th, 2011 AT 3:40 PM

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Tiny
JACOBANDNICKOLAS
  • EXPERT
  • 68,395 POSTS

When this happens, do all brakes lock up or just start to drag? Have you reciently replaced the master cylinder? Have you examined the booster check valve?

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Monday, October 10th, 2011 AT 4:39 PM
Tiny
LBERRY01
  • MEMBER

I have a Sonata 2005 2.7(V6)GLS NO ABS NO Traction Control drive about 4-8 miles depending on the temp. Cooler it takes a little longer, the front brakes lock up till you cannot move. Have redone the whole braking system new everthing ! This car only has 61,521 miles has been maintained well never experience anything else, no noises or anything. Replaced front pads last year. This started out of the blue while driving home, no indication of anything till all of a sudden. Frustrated, and confused cause noone seems to know what the problem is, I have replaced several parts from auto store to another. My car seems to use '04 parts and '05 parts. Have not taken to dealer as of yet, have a personal mechanic by trade that does everything for this car and he cannot figure this one out. HELP! HELP!

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Tuesday, November 1st, 2011 AT 3:34 PM
Tiny
2CARPROS KEN
  • ADMIN
  • 11,719 POSTS

What happens is the internal valve inside the booster gets stuck so it wont release. The booster needs to the replaced or the booster rod is adjusted too far out. Try to undo the mounting bolts for the master to see if that releases it as well if so then turn the rod adjustment screw inward. If not here are some diagrams to help you replace the booster with a rebuilt or new unit.

Please let us know what happens.

Cheers, Ken

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Thursday, September 28th, 2017 AT 3:32 PM

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