[RUN.10W]

reconditioned mate, i still dont think that is the problem, im trying to organize a trailer to trailer it to a shop

[JrZook]

RUN.10W wrote:

Rear brakes have been capped off, same problem,
Steak knife rear brakes have been adjusted.

Have you capped both front and rears together and tried it?

[RUN.10W]

havent capped the front of but have taken calipers to the brake shop they went over them and said they were fine

[royce]

did you bleed the master cylinder?

[JrZook]

royce wrote:

did you bleed the master cylinder?

Also a good Q

[RUN.10W]

Yes master cylinder was bleed also

[royce]

how did you bleed it?

[RUN.10W]

Hope i done it the right way, I bleed it like I did with the brake nipples, got my mate to hold down the pedal while I cracked one hose and checked for bubbles/air then tightened it then pumped it up and done all three lines like that till I could see just fluid, then went and bleed all the lines again?

[royce]

do you have one of the sierras with the bleed screw on the thingo up above the rear diff?

[bagnkat]

royce wrote:

do you have one of the sierras with the bleed screw on the thingo up above the rear diff?

Coilies do have a bleed point on the proportioning valve.

[RUN.10W]

Yes mate I do have one of them valves have bleed it as well,

[RUN.10W]

Ok from the top this may take a while. The brakes where fine then I brought 100mm raised coils, raised the car and then started fitting power steering so it sat for a while. Then realized the brake lines were to short so I got extended one. Done all that got my 33's then started to bleed the brakes. Well I couldn't get pedal so a mate had a look and said maybe the brake lines, so I removed them and put it back to standard just to try that, pedal still a no go. Adjusted the rear brakes bleed lines again, still no good. Removed rear proportioning valve and blocked rear brakes all together still pedal no good. Took front calipers off and took to the brake shop told calipers are fine. Changed brake master cylinder and bleed master cylinder then bleed brakes line all again put back in the proportioning valve re bleed again 100% no air, check cap on fluid holder still fine, checked vacuum line seems fine, and that's where I sit tonight looking at the car trying to think what else....

[RUN.10W]

And have checked every little bit of line or calipers or anything for any leaks or problems though all seems fine.

[steak_knife]

is the bleeder nipple still the highest point of the caliper after lift??
as in the diff has rotated & the nipple's moved..

Is it possible you have an air pocket in the caliper?

[RUN.10W]

Nah well I don't think so from sitting here looking at it the nipple is still the highest point, the diff really hasn't moved at all from standard

[christover1]

Have you done any driving with it yet, sometimes real use is needed to bed stuff in, get air out, free up seized parts that not been used for a while. Most rear brake shoes require use to operate the auto adjusters.

Drive very carefully, tho, expect a failure.
If nothing else, real driving could make fault easier to find.

I doubt the lift has affected anything, but recheck lines haven't been trapped, flattened, damaged or other.

You need to try a booster swap, to rule that in or out too.

After a drive, check everything for leaks, re bleed etc.

[steak_knife]

RUN.10W wrote:

I brought 100mm raised coils

RUN.10W wrote:

And have checked every little bit of line or calipers or anything for any leaks or problems though all seems fine.

would of had to of changed....

worth a try , 4 bolt's to get the caliper's off.

[christover1]

100mm is quite a big lift, didnt really see that .. so stekky could be right.

On my Sierra rear discs, I had to remove caliper bolts, and rotate the caliper till nipple was vertical.....have seen it be a problem a few times on modded cars.

[bagnkat]

I wouldn't be surprised if it was your 100mm lift. As I understand it, the proportioning valve detetects the height of the back of the car relative to the axle. I believe it does this so that when you're under brakes and the weight shifts to the front axle, pressure is prevented from reaching the rear brakes, thereby reducing the chance of a lock up. I noticed this in my coily after doing a 2" lift. I made a bracket to raise the sense arem for the proportioning valve to it's original position relative to the body of the chassis. After I did that, the brakes returned to a normal feel. Perhaps what you are describing is the same thing ?

[christover1]

bagnkat wrote:

I wouldn't be surprised if it was your 100mm lift. As I understand it, the proportioning valve detetects the height of the back of the car relative to the axle. I believe it does this so that when you're under brakes and the weight shifts to the front axle, pressure is prevented from reaching the rear brakes, thereby reducing the chance of a lock up. I noticed this in my coily after doing a 2" lift. I made a bracket to raise the sense arem for the proportioning valve to it's original position relative to the body of the chassis. After I did that, the brakes returned to a normal feel. Perhaps what you are describing is the same thing ?

I just spaced the A arm on my Vit, and that improved brakes remarkably.
Dunno why that thought didnt come to me.
I would think the coilys would have a load sensing proportioning valve

[christover1]

I'll put my money on Bagnkat being right

[RUN.10W]

Bagnkat I thought that as well though I have disconnected the valve and moved it up and down bleed the brakes with it up, set it up straight set it up facing down done all of it and still had no luck, I thought I would pick it up doing that though I may have to try something else with it

[royce]

bagnkat wrote:

I wouldn't be surprised if it was your 100mm lift. As I understand it, the proportioning valve detetects the height of the back of the car relative to the axle. I believe it does this so that when you're under brakes and the weight shifts to the front axle, pressure is prevented from reaching the rear brakes, thereby reducing the chance of a lock up. I noticed this in my coily after doing a 2" lift. I made a bracket to raise the sense arem for the proportioning valve to it's original position relative to the body of the chassis. After I did that, the brakes returned to a normal feel. Perhaps what you are describing is the same thing ?

are they connected to teh diff through some kind of linkage?

FWIW the stoopid pink patrol had random brake peal height problems that pulling its version of one of them out fixed

[bagnkat]

royce wrote:

bagnkat wrote:

I wouldn't be surprised if it was your 100mm lift. As I understand it, the proportioning valve detetects the height of the back of the car relative to the axle. I believe it does this so that when you're under brakes and the weight shifts to the front axle, pressure is prevented from reaching the rear brakes, thereby reducing the chance of a lock up. I noticed this in my coily after doing a 2" lift. I made a bracket to raise the sense arem for the proportioning valve to it's original position relative to the body of the chassis. After I did that, the brakes returned to a normal feel. Perhaps what you are describing is the same thing ?

are they connected to teh diff through some kind of linkage?
FWIW the stoopid pink patrol had random brake peal height problems that pulling its version of one of them out fixed

Yep, see ammended post above for pic.

[RUN.10W]

Maybe even a faulty proportioning valve? I will try and sort something out to get the mount sitting up 100mm higher and see if it fixes, again guys thanks for all the tips and etc it's greatly appreciated.

[christover1]

None of us will sleep till we know the answer

These hard to find issues are common, and though very annoying, the do have the benefit of causing us to fit a lot of new parts, check a lot of things, and learn useful stuff.

Keep at it, you will get there.

[RUN.10W]

Tomorrow i will be stuck into it again, won't give up this time built a zook years ago and gave up and sold it. Biggest mistake I ever made. Will make up a mount tomorrow to move it up 100mm and see how that goes

[RUN.10W]

Raised that arm up still the same no pedal.

[christover1]

RUN.10W wrote:

Raised that arm up still the same no pedal.

after repositioning mine, I needed a fair bit of driving before I noticed improvement.
Good hunting.

[RUN.10W]

Thanks mate