My brakes are giving me a headache...All of my brakes seems to lock up when driving 15-20 min on the road.

I replaced brake booster, mc, booster valve, porportioning valve... and bled the brakes like 6 times...still brakes locks up.

When the brakes do lock up on the road i have to jack up my rex and release some of the pressure and it works fine again.

seems like the booster is at fault and mc... but its my second time replacing the unit...could it be b/c its from autozone? lol.

Any ideas would help... Thanks.

 

Have the same problem changed the same stuff,but with mine if I undo the one way valve they work fine I just don't have power brakes so when I stop I have to push harder.Let me know if you get this fixed and how please.Been ridein like this for over a year.

 

Ah yes, Forgot to adjust my Brake booster pushrod! I read that if not properly adjusted can slowly lock my brakes. Thanks 91zchatch I'll keep this updated.

also the special tool is hard to find, do you know where to find nearby stores or I have to order online?

 

Wow, I'm surprise you drove like that for a year. what did you use to substitute for the check valve? did you reverse the check valve?

 

i heard that the caliper's piston can cause this problem as well.

 

you dont need that stupid tool bro contact me on my phone number and i will tell you whats up easier on the phone then here but it will be easier to do this off the car then on but either way just buzz me

 

This happened to my friend. His calipier pin was bent a little ant it would lock up. check the pins. quick and easy fix

 

I just un did the check valve. It's like a have manual brakes with no booster.not the safe thing but its worked so far but if you get your fixed please let me know.

 

Bump....any progess?

 

Solution! sorry for the late progress> school and parts was back-ordered...

 

I diagnosed the Problems that can lead to Calipers locking front and rear disk brake and drum and it was the Brake booster pushrod.
My pushrod on my brake booster was sticking out too much and it was pushing against the mc while i was driving only.

Thanks to 91zchatch for helping me conclude my diagnose! Props.

although the 130$ tool is needed I didn't need that at all to unlock my brakes and make it roll and drive efficiently.

Here are some tools i need.



- Some pliers to turn the rod adjustment
-and some tools to lock the star nut and hold the 17mm nut thing while turning the rod adjustment.

Here is what i was working inside my rex.

 

The star nut was the only problem, i have to grind my cheap 14 mm with the star shaped boxed side to fit into the push rod so i can break loose the star-locking nut and continue work.

and the rest of the tool- 12mm for the lock nut to the pedal, 17mm to hold the booster side when adjusting the pushrod and a long plier to turn the rod adjustment.

 

Here is what i did.

Torque every thing down and apply pressure. I cant afford the vacuum thing so i used my car assuming its 20 hg of vac. I can feel my brakes locking on my car in few min.



Then after vacuum was applied, and left my car running still, I went under and this is what i barely see.



-I break loose the nut to my pedal, and broke loose the star nut with my home-made 14mm wrench, and then i used my pliers to turn the push rod adj while using the 17mm wrench to hold that nut to the booster.
-I also used some white out to mark the location of the nut and other areas for reference before hand.
-I think clockwise it pushes the rod forward and counter-clock wise it retracts the rod. so i went ccw.

and bam! My wheels unlocked! the clearance from the push rod to the mc is 0.016 in but i did it by feel and turned ccw for 3/4 more.

There it is. Headache gone. I can go 130 mph on my hf with ease, instead of 25 mph, now. <<Sarcastic