1990 4Runner master cylinder problems.

[socalsvt]

Me and the wifey were driving home the other night when I suddenly lost my brakes. Luckily we were right down the street from my house so I was able to get it home using the e-brake and downshifting. After speaking with a few gear head friends of mine, I established that it was a master cylinder problem.

So I went to Kragen on Sunday and picked up a new one. When I got it home I bench bled it in the kitchen sink using the supplied plastic tubes. I did the thing where you hook the tubes up where the brake lines would go, and place the other ends of the tubes into the full reservoir, and pump the cylinder slowly until there is no longer any air in the lines.

After installing the new master cylinder on my vehicle, I bled all four wheels in the proper sequence (RR, LR, RF, LF). To be specific, I did this by placing a plastic tube (which led into a glass jar) over each bleeder valve, I had my dad depress the brake pedal, then I loosened the bleeder valve until the fluid seemed to stop moving through the tube, then i tightened the bleeder. I repeated this process until it was solid fluid (no air bubbles) coming out of the bleeder, then I would move to the next wheel.

After completing this, I pumped the brakes a few times and the pedal felt like it was building up pressure (it would only go half way down). I was tickled to death until I started the motor and the pedal went directly to the floor.
At about this time my apartment manager asked me to stop working on my vehicle because i was "hurting the image" of our community. I can understand where she was coming from, but it still pissed me off.

Anyways, me and my pops jumped in my vehicle and started it up (I was going to move it down the street to a vacant parking lot, where we can work happily with no distractions). As I started going down the street I hit the brakes for giggles and discovered that if I pushed the pedal almost all the way to the floor, the vehicle would stop. At speeds faster than 15-20 the vehicle would still stop, but it would take up a much longer distance in order to do so. At speeds slower than 15-20 mph, the wheels would practically lock up.

Once I got it over to the parking lot. I had my dad push the brake pedal as I loosened the brake lines connecting to the master cylinder. When the brake pedal was on the floor, I tightened the lines. When I did this, there was a solid stream of brake fluid coming out of the lines, so I was reassured that there was no air in the master cylinder.

The brakes are still not working and I have to get to work somehow....any ideas?

[fourwd1]

You may still have air in the lines. Try bleeding some more.
The correct order is
LR
RR
RF
LF
LSPV

[socalsvt]

Originally Posted by fourwd1

You may still have air in the lines. Try bleeding some more.
The correct order is
LR
RR
RF
LF
LSPV

I am sorry, what does LSPV mean?

[Brian R.]

Load sensing proportioning valve

[fourwd1]

It's mounted on the frame, pass side, above the rear axle. A thin rod from it connects to the axle on the drivers side.