Hi all, this problem is driving me crazy!!! The problem is that the brakes take about 2-3 pumps to work properly...Now, I replaced the master cylinder thinking it was bad with a aftermarket parts store reman unit...Still got the same problem..I then bought another one and tried it thinking I got a bad unit with no luck or change better/worse with the problem in hand,..Oh and the mast. cyl was bench bled properly as well as the rest of the truck TWICE with a air powered vaccum bleeder....All the hoses and brake parts function seem to be working fine, no leaks, rubber hoses appear to be in good shape,etc,etc....Any suggestions would be greatly appriciated!!!!Thanks

 

Did you bleed the LSPV, that has to be bled last to get all the air out. The first time I bled the brakes on my Runner I didn't and I had those symptons.

 

LSPV????Does this mean left side prop. valve????Sorry I am not sure what that meant...If so, than no I only did/thought there was one on the right rear side....

 

it's the porportioning valve before it goes down to the rear brakes.
did you check the slave cylinder to see if it works well?

 

Yeah, I bled the prop. valve first...,But from what I have been reading, it looks like it should have been done last..Can anyone verify this for sure????Man, this problems really getting old and annoying!!!!!

 

You want to do the load sensing valve last.

Start with the passenger rear brake, then do the driver's rear. Do the passenger front third, then the driver's front. Then do the prop. valve last.

 

you sure your wheel cylinders are good and whatnot? cause to much play in the rear brakes can equal just what your talking about to, if it was just air in the brake lines you would have a squishy pedal and not a pedal to the ground.

wade

 

Well, I re-bled last night with the air vacc bleader again with no luck...I did it in the correct order of what you guys are speaking of, and its not any better....I took it for a ride, and it takes at least 2-3 pumps to get stopped...This sucks, I am half tempted to buy a NEW master cyl., instead of the $37 remans to see if there is any difference....Any other suggestions??

Oh I pulled the drums as well and everything seems ok, in the rear....

 

when you bleed the brakes are you still seeing air bubbles if you are seeing bubbles keep bleeding also are the rear brakes properly adjusted if the drum came off really easy when you inspected the rear brake shoes then they need to be adjusted also if you have recently lifted your vehicle the arm of the proportioning valve were it attaches to the axle needs to be raised the same amount that you lifted the vehicle you can buy the bracket or make it yourself

 

Actually I lifted it 3 inches about 2-3 months ago, but the problem just started recently..And no, I did not do anything with the prop valve brkt...Is it MANDATORY you have to do what you are saying?????

 

i'm not sure that it is mandatory but alot of the lift kits come with the bracket to relocate the prop arm were it attaches to the axle the only reason i'm suggesting this is that i had similar problems and i replaced everything in the brake system (mastercylinder, calipers, wheel cylinders, shoes, pads, prop valve, lines nothing seemed to help. i had pretty good brakes in reverse but none going forward untill i pumped them a couple of times. in reading on the net i came across a article about relocating the prop valve arm so i tried it and it solved my problem not sure if it will work for you or not

 

Well, thanks for the tip, I might as well give it a try at this point...I will let you know if it helps...Thanks man..

 

Hey guys, I looked into the problem even further this weekend and underneath all the dirt in the rear drums, I found a slightly leaky wheel cylinder on the pass. side...So I replaced both of them with high hopes of solving the problem, and it did not....However, the brakes do feel somewhat different now, you dont have to pump them to stop, but the first half of the brake pedal feels like no pad contact is being made, then it starts to grab a little...It does not feel 100% safe, but will stop the truck....Any other suggestions???Thanks for everyones help..

 

rebleed your brakes now makeing sure you use the proper procedure,

did you clean your drums good? was there any fluid on teh pads or the drums themselves?

another thing may be you need to get a new proportioning valve, and make sure that your residual check vavle is properly working.

best of luck
wade

 

I would try bleeding them the old fashioned way. Have someone pump the pedal 10x's hold it to the floor and crack the bleed screw slightly (just enough to let fluid out), close screw and repeat, over and over until you don't get any air bubbles out. Put a piece of clear tubing on the bleed screw so you can look at the fluid as it comes out. When bleeding the old fashioned way you can get a feel for the pedal as to if you are maintaining system pressure or if you are loosing it over and over.

 

Where is the check valve you are speaking of???And also when the truck is off and were pumping brakes, the pedal gets hard after a couple pumps,and when the truck is turned on, it sinks down abount 1/2 - 3/4 of the way down before the brakes want to grab....

 

Oh, the rear shoes looked fine..They have good life left, and they werent soaked in fluid....The whel cylinder was just barely starting to leak...

 

loose wheel bearing will kill pedal height

and only takes 10 minutes to check. Check the drviers side first. (tends to unscrew when driving forward.)

 

I was told that if you pump the brakes when the truck is off, that if the pedal stays hard your master cyl. is fine, if it goes soft with the truck off the master cyl. is bad.

 

Yeah, I have tried both a new and re-man mast. cyl with no luck....I am still trying though!!!Problem is driving me crazy allready!!