Load Sensing Proportioning Valve

I purchased a 2001 2WD single cab Tacoma DLX with a 2.4l engine and manual transmission within the last two months. It has about 160k on the clock. I had a pulsing coming from the right front wheel, along with a little bit of a roaring. I replaced the rotors, the bearings, and whilst in there, replaced the calipers with remans from Autozone. While bleeding the brakes, I found that I could not get any fluid from the rear wheels. Further investigation revealed that I could get fluid from the LSPV. I tried to manually actuate the LSPV, but still could not push any fluid. The brake pedal would not go down. I am therefore left to believe that the LSPV has failed.

I am contemplating replacing the LSPV with a standard proportioning valve. I have seen several folks talk about doing so. My question is: is there a good procedure showing the parts and such to do so? Also, does anyone recommend any further troubleshooting?

Thanks in advance,
Rob

 

Did you have it jacked up at the time, with the axle hanging by the leafs?

 

No, it was on the ground. I jacked it up this morning prior to posting, put jack stands under the axle, spun each wheel, and pushing the brake pedal would not slow the wheels at all. The parking brake does work, which I know is expected, but, another data point.

 

Actually, I would expect the parking brake NOT to work, only because so many of the PB bell cranks are hopelessly rusted.
Your Master cyl could be bad, or the proportioning valve.
Can you loosen the hydraulic line going into the Prop valve and see if that leaks when you apply the brake? That would tell you if the pressure is getting back there. If not, you have a bad Master.

 

How many lines go into that valve from the front of the truck?
if you do replace the valve, here is how to adjust it initially:http://www.brakeandfrontend.com/Article/72111/tech_feature_brake_job_on_19952004_toyota_tacoma.aspx

 

There are two lines coming from the front of the vehicle going to the LSPV. One down, one back is my understanding. If I loosen the bleed valve at the LSPV, I can get fluid to come out. With these symptoms, I would not think it to be the master cylinder, but, the LSPV itself.

 

I agree.
But the lines are not one in, one return, but both feed lines.