Master cylinder / brakes common problem.

[dms31986]

Just want to share and hopefully save some people some money. I have a 2004 4Runner Sport V8 4x4. 278,000 miles.

I got into my Toyota after work and turned it on, and heard a loud solid tone buzzer with VSC, Trak, ABS, and Brake lights on. I had no idea what this was and it didn't go off in the 20min I had it running. When I pulled out of my drive way I learned quick it was the brake system. After several hours, its the master cylinder. FYI, Toyota dealership will only change this as a complete unit. 2700 dollar part, 400 labor.

What I want to share, and what I found out with the help of research. You can take a metal rod, like a jack rod and hit on the pump/motor on the bottom of the master cylinder unit. Its black and has to wires on it. Car was on and I was tapping away. After about 20 or 30 taps, the motor kicked on and pressured up the system. Alarm noise went off. I pressed the brakes probably several hundred times to continue to see if the motor would fail again and it has not.

So I'm convinced the motor brushes are wore a little internally. You can also buy a pump/motor only for 400 dollars new. Probably find no help installing it, but this can save you thousands if this is the same problem you have.

Just wanted to share this.
Thank you.

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[anotherrunner83]

thanks for the share.

i think i'd be ordering that part! brake systems aren't exactly something you want to chance. i guess you'd still have manual brakes that you'd really have to stand on, but you'd lose the benefit of the booster....i guess.

 

[07V8]

Someone from Hawaii rebuilt the motor. It was all gummed up inside.

 

[AuSeeker]

Someone from Hawaii rebuilt the motor. It was all gummed up inside.

The motor on Hawaiian Hillbilly's master cylinder also had one of the brushes stuck, which is what the OP in this topic had wrong with his motor, his hitting the motor numerous times freed the brush, I would recommend he take the motor apart and clean it and the brushes up to prolong the life of the motor and not just settle for it working again after hitting it numerous times.

http://www.toyota-4runner.org/4th-gen-t4rs/225205-2003-v8-brake-booster-pump-diy-fix.html

 

[dms31986]

thanks for the share.

i think i'd be ordering that part! brake systems aren't exactly something you want to chance. i guess you'd still have manual brakes that you'd really have to stand on, but you'd lose the benefit of the booster....i guess.

Really not even manual brakes...I'm not driving it until motor replaced.

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[BlackWorksInc]

The motor on Hawaiian Hillbilly's master cylinder also had one of the brushes stuck, which is what the OP in this topic had wrong with his motor, his hitting the motor numerous times freed the brush, I would recommend he take the motor apart and clean it and the brushes up to prolong the life of the motor and not just settle for it working again after hitting it numerous times.

http://www.toyota-4runner.org/4th-gen-t4rs/225205-2003-v8-brake-booster-pump-diy-fix.html

Actually it could also be a burnt commutator bar, by hitting it you're "jiggling" it some and may get it to spark and thus rotate to a non-failed one. Same thing with starters.