Soft brake pedal...

[toy4xfun]

hey if you here hissing or air leaking you need to see if it happens all the time, when the pedal is depressed or does it do it just as the pedal is depressed (stops when pedal stops moving). a master cylinder can leak internally and cause the problem you are talking about. it will stay full what happens is fluid leaks through the internal seal that is supposed to direct fluid out to separate lines.

 

[1BADAWD]

The hiss of air is AFTER the truck has been ran and pedal pushed. Shut off truck, without trouching pedal you can hear the air.

 

[toy4xfun]

i would say you have a leak in your booster. but i would still change the master cylinder. the last master cylinder that went out on my truck did not leak it went internally. started out the pedal was soft and it did not take long it started sinking to the floor with very little breaking.

 

[1BADAWD]

Yea pedal goes close to floor before braking. Still brakes pretty good.... when it finally starts, haha.

 

[raydouble]

I think you need both master and booster......
Got to pinpoint the leak (hissing) you are hearing though.

Maybe the master is leaking into the booster?

 

[toy4xfun]

ray double could be right . but when i had one leaking from the back you could see the fluid running down the booster.

 

[1BADAWD]

I cant see any fluid leaking or running out anywhere i dont believe.

 

[1BADAWD]

Ok so we popped the rear wheels off today, bled both rear brakes and went to adjust them. Right side adjusts fine and it set pretty good now. The left side however... turns like it adjusting but when apply the brakes there is no change.

 

[zombie]

You said it has a 2" body lift. You need to adjust the rear brake height adjuster (sorry I don't know the technical name for the part) to compensate for the lift. It has a bar that connects to the body and pivots according to ride height. Theory is that as your back end sits lower with more weight you need more rear brakes or if it sits higher the back end is lighter needing less brakes. It directly affects the pedal feel and right now your brakes are not working in the rear because of this. I adjusted mine by adding a 2" bracket to it where it attaches to the axel after doing a 2" body lift and it made the soft pedal firm again.

 

[alteredraptor]

its actually just the driver side rear brake thats not braking... the passenger side does stop and quite nicely now since i had to adjust it, but good to know, me and him will have to try that

 

[Tools R Us]

Ok so we popped the rear wheels off today, bled both rear brakes and went to adjust them. Right side adjusts fine and it set pretty good now. The left side however... turns like it adjusting but when apply the brakes there is no change.

Did you pull the drums, are the adjusters turning freely, is the hardware correctly installed? In theory they are self adjusting, but often don't keep up with wear, so sometimes need manual adjustment. I turn the drum/wheel, adjust until drag is felt.

You said it has a 2" body lift. You need to adjust the rear brake height adjuster (sorry I don't know the technical name for the part) to compensate for the lift. It has a bar that connects to the body and pivots according to ride height. Theory is that as your back end sits lower with more weight you need more rear brakes or if it sits higher the back end is lighter needing less brakes. It directly affects the pedal feel and right now your brakes are not working in the rear because of this. I adjusted mine by adding a 2" bracket to it where it attaches to the axel after doing a 2" body lift and it made the soft pedal firm again.

All of the LSPV (load sensing proportioning valve) that I have seen on trucks are mounted to the frame, with the other end going to the axle. So a body lift will not effect it's operation or require adjustment.

 

[alteredraptor]

Did you pull the drums, are the adjusters turning freely, is the hardware correctly installed? In theory they are self adjusting, but often don't keep up with wear, so sometimes need manual adjustment. I turn the drum/wheel, adjust until drag is felt.

tried to pull the drums... passenger side didnt want to, driver side almost came off, but started to bind up on the shoe itself... so we couldnt see exactly how the hardware was... but the adjusters worked, the drivers side worked, but the little stopper tap wasnt working... kinda had to stop work for the day on account that it was just getting too cold and dark, and the wheels were spinning when they got adjusted

 

[1BADAWD]

Yeah from what we could tell, the shoes had some life left as well. Next time we probably can get the drivers side drum off if we adjust the shoes back and see if anything is binding up.

Still gotta figure out the air hissing by the mc/brake booster as well.

 

[1BADAWD]

Any tips at getting the drums off when they are stuck? I cant tell if they are stuck on the shoes or on the inside where it touches the hub.

 

[raydouble]

Any tips at getting the drums off when they are stuck? I cant tell if they are stuck on the shoes or on the inside where it touches the hub.

2x
M8 x 1.25 40 or 50mm long bolts

They thread into the drums and help push a stuck drum off......make sure the e brake is off.

 

[1BADAWD]

Ill get some of those. Thanks for the tip.

Do you think the one rear brake not workin well would cause that soft of a pedal?

 

[zombie]

All of the LSPV (load sensing proportioning valve) that I have seen on trucks are mounted to the frame, with the other end going to the axle. So a body lift will not effect it's operation or require adjustment.

You are right, I checked my truck and it is mounted to the frame. I forgot that at the time I did the body lift I also increased the spring lift by 2" and that is why I had to make the bracket to mount it higher.

 

[raydouble]

Ill get some of those. Thanks for the tip.

Do you think the one rear brake not workin well would cause that soft of a pedal?

I don't think so........
If you can "pump" it up, I would say it's the seals in the master or air in the system.

 

[1BADAWD]

Yea i was thinkin the issue was more in the mc/brake booster area, but i gotta attend to the rear hardware and whatnot as well. Would be nice to have all 4 wheels actually braking.

 

[Tools R Us]

Ill get some of those. Thanks for the tip.

Do you think the one rear brake not workin well would cause that soft of a pedal?

It can, drum brakes are spring return, the adjuster determines how far the shoes return/retract. If not adjusted correctly, the shoes will pull back too far causing the peddle to need to be pumped to move them enough to contact the drum. The same effect as when calipers are compressed for new pads, but happens each time the brakes are used.