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

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Had the same thing but different. On mine the armature actually was burnt. Solution was to chuck in a lathe and take a little off the top. On yours I would at least have cleaned up the armature with a little emery paper to get another 200K out of it!

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awesome my friend! yes I didn't have emery cloth on hand so I did what I could with steel wool before I installed it again. Its amazing the things we can achieve with a little help from other T4R enthusiasts! aloha from Hawaii....HH

Very good write-up and I'm glad that everything worked out for you. Seems like the motors end up popping off on these systems more than anything, so for those who aren't feint of heart it's a worthwhile solution.

If you ever find a rebuild kit for these please update the thread with part numbers, I haven't seen anything last I checked; but I'm just one guy. Supposedly some member said he rebuilt these things but he/she never provided any further information, so I suspect they were a "click-bait" spammer.

Well played. I'm sure this post will be invaluable to many as time goes on. Thanks.

I sure will Black! I'm super stoked that it worked out. Ive heard more about the rebuild kits available but nothing solid as far as the retailers. I know some alternator shops may be able to help as well. Found one place in California that can rebuild the pumps for around 250 bucks. they offer the parts to I think. I found it in this forum but lost the thread. alohas for now! HH

Right on! I hope that this post will help anyone willing to dive in on a refurbish job. Saw a few threads and I looked at it as "well its already broken so lets dig in!" was glad to see that the brush was stuck. mahalos. HH

I was so glad to see that it was an easy fix gang! Now the wifes 'new to us" 03 T4R V8 will be on the road today after I get the front axles and calipers changed out. Will post pics of that as well. Shes diving to the right when I hit the brakes now so I'm assuming front calipers are frozen or about to be....hate these things on our runners. Ive read a few threads in here about the 5th gen or fj caliper upgrades but was wondering what the part numbers are on those. Especially with the differing rotor diameters on our 4th gens. Someone please inform....mahalos all! HH

what are you going to loose by opening it up? nothing at all, just gaining pure new knowledge. I guess in your case, that's your only option. that's how we should do things if you want to avoid spending too much.

pm me your email, i'm actually sending my 5thgen upgrade PN spreadsheet to another member tonight, i'll just include you. do your research though!

This post just took so much worry off my mind! Good job on the successful rebuild!

THANK YOU FOR THINKING OF this Hawaiian Hillbilly! I truly appreciate it!

I am very glad that it was an easy fix and can help other T4R peeps out if this ever happens to them. sharing is caring and ive learned a lot about my runner because of this forum. So much so that I got the wife a 4th gen too. awesome rigs to have fun in and a daily driver too. aloha. HH

Mahalo nui loa, bro. You posted some very valuable information here! It will help many.

exactly my friend! we were ready to take it to the Toyota dealership for service after I do the front axles but....thankfully it was good news. much aloha, HH