dhall50

Hey, I just bought this truck and am chasing some issues down. The Master Cylinder had been leaking into the brake booster so I replaced both and bench bled the MC. Now when I try to bleed the brakes only the front and the lps or what ever bleed just fine. When I try to bleed the rear brakes almost nothing comes out and opening the valve does not make the pedal go to the floor. The bleeder valves are not plugged. The pedal is super spungy and wont build up much pressure. The truck has 3 inch body lift and I noticed the thing in the rear of the truck is only zip tied. Any input would be great.

yoterr

well the thing in the rear is ur Load Sensing Proportioning Valve or LSPV .. kinda need that for the rear brakes to work properly, also it might be clogged?? might be the reason why no fluid is coming out of the rear brakes, and the reason for the brakes being spungy is air, i know you said you blead the whole system but theres prolly still air in there, i blead my moms nissan at least 4 times with no avail.. and finally i just opened the bleader screw until fluid came out, and blead about a bottle of fluid and saw all the air bubbles come out, then i blead again and everything was good. same with my yota

limon32

I'm having the same problem. I've tried traditional method and vaccum bleeding. I thought I had all the air out today and then the brakes were worse than when I started! I am curious just how much bleeding is typical for toyota brake systems? Is there something particular about the bleeding process for these trucks? Does it really just take a lot of bleeding?

dhall50

Well i just did it for an hour and I think I finally got the air out. I am just Hoping I dont have a leak that is letting air in and I go out to the truck with no brakes in the morning. Its not my dd but hunting season just started!

limon32

Ok, I definately haven't bled for that long, let me know if your problem is solved, i'm going to go bleed some more today...

dhall50

I wont say solved but better. I also discovered lpv thing shouldnt have been zip tied all the way up like it was.

limon32

Hey dhall50, I solved my problem tonight by pushing fluid from the resevoir ports to the bleeder screws with a large syringe. This was the ONLY way I could get all the air out of the master cylinder. I tried every other way I could imagine, then I recalled the syringe that came with the new master and finally realized what it was for. Let me know if you need more detail.

dhall50

I solved the issue with my truck.

Number 1: The brake booster rod was not adjusted out far enough. I had no idea it was adjustable(my bad).

Number 2:The LSPV for my truck needs to be replaced. While bypassed my Brake Popping(feel hard and then pop and go down a few inches) went away. When hooked back up and bled correctly the pop returned. No biggie. My buddy has a parts truck, ill nab his one of these days.