Still having brake issues

[88pioneer]

Fixed the PS drum and bled the system, still no dice. The rear prop valve is still in place, and i have read up on how to bypass it, but its not making sense to me. If someone could elaborate for me i would appreciate it. I need it done today so i can get to school tomorrow, I appreciate the help

[Automan2164]

How are you bleeding the brakes? Are the cylinders right side up? Did it get low enough to suck air into the master?

 

Rob L.

[88pioneer]

the cylinders are in the right way, and the master still has fluid. Does this have something to do with the load sensing valve being hooked up still?

[Automan2164]

I have never really had a problem with the load sensing valve when bleeding.

 

Have you bled brakes before? What is your procedure?

 

Rob L.

[kastein]

My suggestion - get speed bleeders. Never used to think they would make much of a difference till I got a set.

 

Also, bleed all 4 wheels, then open a front bleeder, jam on the brakes to shuttle the prop valve bypass, bleed the rears again, shut the front bleeder and bleed all 4 in normal order again. That's the method with the height sensing valve in place, though I have good braking without doing the extra steps, might just be because I'm used to the way it was with air in the rear lines and only the fronts working for a few months.

[88pioneer]

bleeding the brakes, i cracked each bleeder one at a time, and pumped them until they were dry. Put fresh fluid in the master and cracked the bleeders one at a time again, and pumped until i got a steady stream coming out of each one.

[Automan2164]

Pumped 'til the were dry!? If you did that, you might have introduced air into the master, and you might have to bleed the master. Essentially, you do not want the master to go empty, unless you are replacing it.

 

How I usually do it:

 

Replace any lines/components.

 

Soak all bleeders in penetrant

 

Break all bleeders loose, then retighten

 

Grab an assistant, have them pump 3-4 times, hold, and crack the bleeder on the right rear (or furthest bleeder from master, working to closest).

 

Close bleeder, have the assistant pump and hold again until you have no more air in line. I usually also do it until I have clean fluid also.

 

Repeat on all the bleeders, and once your done, make a few hard two foot pedal smashes, to make sure there are no leaks/weak lines/bad parts.

 

Its important to close the bleeder when the pedal is released, as they can suck air back in. Crack when held, closed when pumped.

 

Rob L.

[88pioneer]

well i tried the standard way an still nothing. I didn't shut the valve when the pedal was released so maybe it brought air back in. I guess i'll try 1 more time once it gets a little cooler out. Hope it works cause this is getting :wall: :headpop:

[Automan2164]

Additionally, if you did pump until dry, you might have to bleed the master. You just make 2 short lines or put some rubber hoses on a couple of short lines back into the master. Then all you do is loop them back in, and pump repeatedly until there is no air.

 

Rob L.

[88pioneer]

so is there a hook up to bleed the master, i'm a little confused on the explanation :dunce:

[Automan2164]

To bleed a master, you pull the lines off, and put on lines or hoses that just loop back into the reservoir. All your doing is pumping them out to dump back in, until there are no bubbles left.

 

Here's a vid showing the loops.

 

Rob L.

[88pioneer]

ah, makes sense now. I'm going to try bleeding them again an than i guess i'll try and find hoses to fit the master

[Automan2164]

Most the time, you shouldn't have to bleed the master, just follow the bleeding procedure I posted, and you should be fine.

 

Just pump, pump, pump, hold, crack the bleeder until the fluid stops, close the bleeder, and repeat until all bubbles are gone.

 

Rob L.

[maddzz1]

Here are some pics that may help explain the rear prop valve bypass:

 

 

 

[88pioneer]

Tried again and i'm really at a loss. Pumped the brakes, cracked them, fluid came out in a solid stream, closed the bleeder. Did it on all 4, and had good pedal pressure. Started it up and its gone, pedal to the floor, brake light on, and hardly any pressure :huh???:

[maddzz1]

Are you bleeding in the correct oreder:

pass rear

driver rear

pass front

driver front

 

and are you keeping the pedal pressed until you tighten the bleeder. I usually do each 3X before I move to the next (pump brakes and hold, open bleeder, tighten bleeder, release pedal)

[88pioneer]

yep, did them all in order and closed the bleeder before letting go of the pedal. It just seems strange to me that it had good pressure, than just disappeared

[maddzz1]

Not positive but I think that may be a sign of a bad booster. Is the vacuum hose for the booster connected? Is it cracked? When you press the brakes and release are their any bubbles coming up in the MC?

[88pioneer]

somethin else to check i guess, i'll see what i find

[88pioneer]

Vac line is good, and bubbles coming up.

[Automan2164]

Might have to go ahead and bleed the master.

 

Rob L.

[88pioneer]

yea i guess. I figured if the master had air in it that it would keep pushing bubbles out of bleeders, but its been coming out steady

[Automan2164]

yea i guess. I figured if the master had air in it that it would keep pushing bubbles out of bleeders, but its been coming out steady

 

In theory, yes. But, Masters usually take awhile to bleed out, and they will keep sending all that air down the system. Best to loop the lines, get it going good, and then do a final rebleed of the system.

 

Rob L. :thumbsup:

[maddzz1]

Or you may still have a leak somewhere in one of the lines or maybe the other wheel cylinder is leaking. But i would start with the master

[88pioneer]

The other cylinder was also replaced, and i guess i'll give the master a shot Wednesday. No time in between now and then :fs2: