Brakes locked up AGAIN!

Screw it! Just cut a hole in the floor and stop Fred Flintstone style.

 

Just got down and checked all calipers and drums and no signs of any fluid leaking. Waiting on my friend to come by to help check the brake peddle push rod length and triple check the calipers again.

 

The brake peddle goes right to hard as a rock after the first pump of it with the vehicle off.

 

From your description in your fist post it still sounds like the booster is going bad. And when you say if you pull the vacuum line off of the booster it works OK for awhile that points to the booster again. I'm out of ideas. maybe give the dealer a try?
Good luck.

 

If it were me, I would "double down" and replace the booster. If you cut it open, there are two things that have to happen. The booster is a double chamber with a plate / diaphragm in the center. Normally vacuum is on both sides of the diaphragm so it exerts no force on the master cylinder. There is an internal bleed passage that equalizes the vacuum on both sides. When you press the pedal, you close this bleed orifice, AND break the seal on the pedal side of the vacuum chamber letting atmospheric pressure in which applies pressure on the diaphragm and pushes on the master cylinder. OK so far. Now, when you release the pedal, the back chamber should be re-sealed again, and the bleed circuit should equalize pressure on both sides and remove the boost.

He is saying that by removing the vacuum line the boost goes away, which says to me that either the bleed circuit is defective or the seal on the back (which is supposed to close to allow the bleed circuit to equalize pressure and remove boost. Either will have the same effect. It is an almost certain thing that the booster is bad.

 

No I really appreciate all the help and advice I'm going to check the push rod length first and take it for a drive and it does this again I'll order a booster. Thanks again!

 

Yes after the push rod check I will try and find a booster. Thanks again guys!

 

Would it be possible to diagnose this by pulling the ABS fuse?

 

There is no relationship between the brake booster and the ABS system.

 

I was referring to the comment about problems caused by an ABS wheel sensor.

 

Sorry, the thead is all over the place.

 

Sure, that would help to determine if the issue is ABS related or not - which in OP's case based on the info we are getting, I'm confident is not related to the ABS as I said previously.

 

Pulled off my booster today and heard something rattling around inside and this eventually fell out. Any idea what it is? I installed a rebuilt booster and took it for drive on the highway and side streets and the peddle felt great so hopefully this was it.

 

Is it tapered on the black face side? A vacuum valve of some sort perhaps?

Ever the persistence has paid off.

 

Yea looks like its tapered on one side and on the other side it looks like it sheared off something. I have my stock booster debating on sending it out to get rebuilt just to have a spare or sell it on ebay. I also want to rip it open and see exactly what that part came off and to really see how the thing works.

 

Just think. Now your truck is no longer a death trap.

 

Dig into it, and share. I am extremely curious.

 

omg you guys were a help and I know some got aggravated at me for just throwing money at it but I learned my lesson!

 

I'll pry it open and post a step by step picture log.

 

Is there a brake proportioning valve on an 07 Tacoma TRD Sport? So far I have replaced the lines, master cylinder, wheel bearing which was bad anyways, inspected the calipers which are the ones that lock its always the front at least thats where the smoke and smell is after it happens 3 times now all on highway drives, and most recently I replaced the booster which made the peddle feel better kind of hard to describe but it feels more firm like it did when I first bought the truck before this it was almost spongy at times not consistent. I'm trying to figure out what else I could look at.