Originally Posted by Hawaiian Hillbilly

Ok first off......THANK YOU TO THIS FORUM! Once again after searching through this forum I found a few threads and subsequent links to help me decide what was my next step in diagnosing my wifes 03 v8 4x4 4runner booster pump failure.

Symptoms: FLAT ASS BRAKE PEDAL! has brakes but very evident the booster was not functioning. I needed to stand on the pedal to get the car stopped. No sound coming from booster pump when ignition is turned on.

While searching for parts I quickly found out how EXPENSIVE this piece was! GEEEEESH! Dealer wants near 3500 bucks for a replacement......you can get used pumps and masters off of ebay from $800-$1500 and up! So needless to say I was not a happy Hawaiian hillbilly! However, I did find some good points in this forum which allowed me to tear down my master assembly and narrow it down to the accumulator and booster pump.

So, I took it all apart and focused on the booster pump itself since the problem was either the booster wasn't getting power or the booster was fried. I first tested the circuit to be sure the pump was getting power. At that point I was fairly certain that the problem was the pump itself. So I separated the pump from the accumulator. Then ripped into the pump itself and found that one of the 2 brushes which transfer power to the pump armature was stuck in the off position. Thankfully this hillbilly also owns r.c. cars and was somewhat familiar with how these things operate. I first removed the stuck brush and filed the rubbish off of the brush that was accumulating over the vehicles 271,000 miles. It was pretty gunky in the motor. Then cleaned out the motor replaced the newly "refurbished" brush and spring....and VIOLA! Tested the pump and I had rotation!

Reinstalled everything in its original places on the master and then mounted everything back into the car....followed the procedures (found in this forum) for bleeding the pump and accumulator (key off depress brake pedal 20-30 times then 10 solid pumps and turn ignition on listen for pump to operate) then continue to bleed each caliper normally. I sincerely hope this post will help someone out there save some hard earned cash!!

Here are some pics that I took throughout the journey. This Hawaiian Hillbilly needs my fireball and dissarono on all repair jobs....WOOOOO! 70% FIREBALL and 30% DISSARONO for those who may want refreshment specifics...aloha, HH

Originally Posted by earthrealm

The ebay unit i installed about 5 yrs ago has failed yet again. I isolated the problem to be a bad pump and possibly leaking piston. The pump doesnt come on.
I have removed the pump and confirmed that one of the carbon brushes have worn down, and stopped making contact.

I am unable to remove the motor bearing as circled in the pictures below.
2ndly my motor appears to be slightly different from yours. Could you confirm how you were able to remove and reinstall the pump coil?

Originally Posted by space city

I used a Dremel tool with a diamond cut off wheel to remove the bearing

Originally Posted by Hawaiian Hillbilly

Ok first off......THANK YOU TO THIS FORUM! Once again after searching through this forum I found a few threads and subsequent links to help me decide what was my next step in diagnosing my wifes 03 v8 4x4 4runner booster pump failure.

Symptoms: FLAT ASS BRAKE PEDAL! has brakes but very evident the booster was not functioning. I needed to stand on the pedal to get the car stopped. No sound coming from booster pump when ignition is turned on.

While searching for parts I quickly found out how EXPENSIVE this piece was! GEEEEESH! Dealer wants near 3500 bucks for a replacement......you can get used pumps and masters off of ebay from $800-$1500 and up! So needless to say I was not a happy Hawaiian hillbilly! However, I did find some good points in this forum which allowed me to tear down my master assembly and narrow it down to the accumulator and booster pump.

So, I took it all apart and focused on the booster pump itself since the problem was either the booster wasn't getting power or the booster was fried. I first tested the circuit to be sure the pump was getting power. At that point I was fairly certain that the problem was the pump itself. So I separated the pump from the accumulator. Then ripped into the pump itself and found that one of the 2 brushes which transfer power to the pump armature was stuck in the off position. Thankfully this hillbilly also owns r.c. cars and was somewhat familiar with how these things operate. I first removed the stuck brush and filed the rubbish off of the brush that was accumulating over the vehicles 271,000 miles. It was pretty gunky in the motor. Then cleaned out the motor replaced the newly "refurbished" brush and spring....and VIOLA! Tested the pump and I had rotation!

Reinstalled everything in its original places on the master and then mounted everything back into the car....followed the procedures (found in this forum) for bleeding the pump and accumulator (key off depress brake pedal 20-30 times then 10 solid pumps and turn ignition on listen for pump to operate) then continue to bleed each caliper normally. I sincerely hope this post will help someone out there save some hard earned cash!!

Here are some pics that I took throughout the journey. This Hawaiian Hillbilly needs my fireball and dissarono on all repair jobs....WOOOOO! 70% FIREBALL and 30% DISSARONO for those who may want refreshment specifics...aloha, HH