So I picked up a used GX470 Sport with 95,000, and knew is had some brake issues when I got it. As I assumed, it had the typical locked up front caliper. So after replacing both front calipers, cutting rotors and putting in factory pads and shims I went to bleed the brakes.

I used the key on, pump up the brakes, hold pedal down and let the pump push out the fluid. As it turns out that only works on the drivers front, and passenger side rear. It'll sit there and pump out ounces and ounces of fresh brake fluid. However on the passenger front, and drivers rear, the pedal just goes to the floor when I open the bleeder, and it just gives a squirt of brake fluid, like traditional old school bleeding. Is this normal, or should all 4 wheels work the same with the pump pushing the fluid out?

Test drive it gently and the car stops fine. Try a panic stop and the thing wants to turn right, and tries to kill me

I've even put the Techstream on it, and tried that bleeding procedure and same thing.

My heart and my brain are telling me it needs a new Master/Brake Booster but my wallet is telling me to try something else. Anyone have any ideas, or do I just go get a second job to afford this brake "the bank" job. I was counting on a KDSS failure being my biggest risk with this, but this is making me miss my 4Runner.

 

Most likely there is still some air in the system somewhere. You might want to do a brake fluid flush. The front calipers are fairly straightforward. See the link below for the rears. https://www.clublexus.com/forums/gx-...ar-brakes.html

 

When I did mine, I just started the truck when doing the rears and had wife work the pedal.

 

BP4R Thanks for the reply. That's one of the the bleed procedure I've tried. However it's not working as it should on my truck. On the passenger front, and drivers rear, the pedal just goes to the floor when I open the bleeder, and the pump doesn't push anything out. (Key on battery charger connected) So on those wheels, I have done a traditional bleed, 4 times now. I have put 2.5 Liters of brake fluid through this thing so far. I expected all 4 wheels to have the pump push out the fluid, and that doesn't happen. I even used the Techstream which does a closed loop front wheel bleed, and a standard real wheel bleed. Same problem.

 

http://www.popularmechanics.com/cars...-bleed-brakes/

First you bleed the Master Cylinder. Then the wheels. You need to use a hose. You need to use two people. You need to push till fluid comes out of every piston. Far to near. You need to push to the floor. HOLD THE PEDAL DOWN, close the valve. Repeat.

 

Do we know what the 1st gen GX brake fluid capacity is? I just did fluid flush/bleed and ran one quart through. It looks clean. I used Synthetic DOT 3, which is completely clear. OEM fluid was yellow when I started flushing. It came out of 08 with 95K miles. I dont know if I should go get another quart and keep going....

 

So is possible to simply hook up a Motive Bleeder bottle to the fluid reservoir, and then open the bleeder nipples at the wheels? All this talk of pumping the pedal, ignition on, etc... is so confusing.

 

I used this to bleed the brakes....not sure if it will help you though. It sounds like ur being pretty thorough .
Let us know what it turns out to be....hopefully not the booster....
http://www.harborfreight.com/automot...der-92924.html

 

To do it right you really need two people. Just pump until clear fluid some out. Make sure the hose from the nipple is submerged. When clear comes out start closing the nipple on the downstroke at the bottom of the stroke and open it once the pedal is released. This will clear any remaining bubbles in the line. Key is to not get bubbles to begin with. That is why you submerge the tube in the bottle so no air can get sucked in. The final pumping with the pedal to the floor and tightening the nipple and releasing the pedal and then loosing the nipple for the next push just clears the last little bit out.