longbow

I am having a hell of a problem getting my brakes working on this truck. Its an 89 4x4 pickup 22re.

The pedal stays spongy and never pumps up. I have some brakes but not much. I have bled every way I can try. Two person pumping method. The tube in a jar method, Gravity bleed. I found instructions here to make a power bleeder that pressurizes the master cylinder with an air compressor. No luck with that either. I have probably put over 2 gallons of fluid through this truck.


I have replaced the master cylinder 3 times so I am pretty sure its not the problem.
I put on new front calipers and brakes. (They are on the correct sides)
New rear wheel cylinders and brakes.
New brake hoses.
Replaced a rusty looking line on the driver front wheel.
Replaced the Power booster.
Adjusted the rear brakes multiple times.

I get fluid out of all the bleeders and never see any air.
Fluid levels never drop so no leaks.
The fluid coming out of the rear brake bleeders does not seem to come out as fast as the front. I am not sure if thats normal or not?
I get good pressure when I bleed the LSPV. I have bled it many times with the level adjusted up and down. Seems to not make a difference.
I have cracked open lines all over the place when bleeding trying to find an air pocket. No luck with that.

I just dont know what the hell is causing this.

The only thing I can think of for me to try next is change out the LSPV or take it off and clean it. I have my doubts that its the LSPV too.

Any ideas?

CJM

Tried adjusting the booster pushrod?

Romans117

Air is getting in somehow.

longbow

I compared where the new one was set to the old one when I changed it. It was pretty much the same. I have bled the master cylinder while it was bolted on the truck with the clear hoses attached and routed back in to the reservoir. When I did that I seen fluid pushing through the complete pedal stroke so it should be pretty close. I guess I could try bringing it out some more but I dont think thats it.

longbow

It never comes out though.

wyoming9

iTrader: (1)

Some place in all the connections you made you have at least one bad one perhaps more.

I have never bleed a Master Cylinder in my life My one attempt at bleeding a LSPV was very expensive and not my vehicle.

Yet I always get good Brakes when done.

Does the 89 Have those goofy rear antilock brakes that works off the power steering pump I know a few years had that enough to drive you crazy.

longbow

Consider your self lucky then LOL. This thing has absolutely drove me nuts. I have checked and re-checked connections and see no sign of leakage anywhere. I would think if I was getting air in the lines that I would get some out later on when I was bleeding it. Also it never pumps up to a hard pedal. Stays spongy and feels like nothing when the vehicle starts and the power kicks in.

No antilock brakes on it.

wyoming9

iTrader: (1)

You don`t mention Drums or Rotors ??

Did you measure either of these ??

Just how tight are you adjusting the rear brakes.

So the emergency brake keeps the tire from turning??

Did you get the wrong pads or shoes??

The new pads are pushed up against the rotors??

longbow

The pads are tight on front rotors though I have not measured anything. I have adjusted the rear shoes till I can barely turn the wheel then drove it down the road and adjusted it again.

wyoming9

iTrader: (1)

Bad brake hoses that are swelling taking up all the hydraulic fluid .

If when you were doing the two person bleeding and the pedal never got hard after pumping something is wrong someplace.

Have you tried with the master cylinder installed running a closed loop of brake line to see if pressure builds

curious just which brand master cylinder??

In this day of poor quality control it is possible you have 3 bad ones or even boxed wrong.

With most all parts coming from China lots of failures.

Romans117

"Bad brake hoses that are swelling taking up all the hydraulic fluid." Absolutely.

longbow

I have replaced all the soft lines except the front drivers side because the parts stores did not have it at the time. I will go ahead and replace it soon but I plugged that line off and did not get a pedal either so I do not think its the problem.

I tried putting two screws in the master cylinder ports and plugging them off. The Pedal got hard then. The first master cylinder was a rebuilt aftermarket one from Oreilys. Second was a new aftermarket one from Advance auto. This is the one I blocked off the ports so I was pretty sure it was good. Then I thought possibly they may of gave me one with the wrong bore so I went and got another and made sure it was 1" bore. This one is a rebuilt ASIN by cardone that came from Advance auto.

wyoming9

iTrader: (1)

I meant your new hoses might be bad right out of the box!!

If you have all new brake parts .

The rear shoes are adjusted up.

All your connections are good They can suck air and not leak fluid.

You know how to bleed brakes Not being smart ??

With the whole Brake System apart your saying you never got any air out??

Just how do you think the air should look depending on which method of bleeding you use it all appears to look different

Cracking a line open will just draw more air into the system .

I really like my vacuum bleeder but even so you gotta make sure to close the bleeder before releasing the trigger.

You have all the air out ?? Your not getting any out!!

No massive leaks of fluid !!

The only thing left is the new Brake hoses!!!

OR

*** Your not really sure how to bleed your brakes.

Or a poor connection is sucking air or several connections

Has this Truck ever had good brakes ??

jarheadtex

Mine is the same way. I just plan way ahead and try to always have an escape path hahaha!!!

longbow

Yes I know how to bleed brakes. First time I bleed with a person pumping them a few times and holding pressure while I crack the bleeders. Did this in correct order and did it 3-4 times. Then I tried the gravity bleed by opening bleeders on each brake in correct order and letting about half a reservoir of fluid out each time. I also tapped on stuff with wrench to dislodge bubbles.

I then built the power bleeder setup. This is not a vacuum bleeder. This pressurizes the master cylinder at 15 psi and keeps constant pressure on the line while you crack open the bleeders fluid just squirts out in a stream.

I found instructions on this site for it. Looks like this




Yes I did get air when I would change a part but then nothing but steady stream of fluid.

After doing all this bleeding and never getting a pedal I resorted to cracking open line fittings in different areas (While under pressure from power bleeder) hoping to find an air pocket somewhere that just will not bleed out.

I do not think its air in the lines.

This weekend I plan on to trying to complety block off the rear brakes and see if I get a pedal. If I do then I will re-examine the rear brake pads and if that's ok I will change out the LSPV and lines. If I dont get a pedal I will start looking at the front lines I guess.

Yes the truck had good brakes before. The pedal became soft and I started with the master cylinder thinking this was the problem but it seems it was not the problem.

wyoming9

iTrader: (1)

I wish you the best of luck!!

Please let us know what you find.

Jeenyus04

you find anything?

AdmiralYoda

You bled the LSPV right? I've never had to because I have a manual proportioning valve but I've heard its a pain.

Since you are already in deep...I like your idea of blocking off lines to try and troubleshoot the faulty part. Block off the rear port at the master cylinder and see if you get a hard pedal. If you do, block off the front port. At least that way you can figure out which half is malfunctioning.

Do you get a good pedal when pumping up the brakes with the engine off? Maybe the booster is acting up?

How are your wheel cylinders? I had one go bad once. It didn't leak fluid but it was mostly frozen. Air was getting in somehow at the wheel cylinder.

longbow

I gave up on this. I just drive it with spongy peddle now. It stops good enough. I never changed the LSPV out yet. That and all the hard lines are the only thing left. I suspect the problem is either in the LSPV or it has some kind of blockage in the lines.

AdmiralYoda

You mention that you didn't change the LSPV....but did you bleed it? Many people have complained about that POS and many times the brakes had air because it had never been bled. Its as important to bleed that thing as it is a caliper or wheel cylinder.

Oh and look at that.....didn't realize someone brought this thread back from the dead.

You've gone this far. I say bypass the LSPV if its the issue and find the darn problem. Brakes are pretty important. Especially when a tweenage girl thats texting on her phone swerves in front of you because she is trying to put on her lipstick with one hand and smoke a butt with the other. Brakes that are good enough might not be then...