Airpak not releasing

[wcolt45]

Been having a time with my brakes locking up,fluids not going back to m/c i can crack a line and its good for a bit then same thing,rebuilt the airpak recently and wander if i made a mistake somewhere,when they are locked cracking the bleeder screw on airpak does nothing,but when i crack the feed line at airpak to wheels it frees them up, put air tool oil in the can and at the compressor but didnt help,pedal is rock hard,what do i need to look at now?

 

[doghead]

Did you rebuild your master cylinder? If not, I think you need to. there are 2 tiny holes that can plug up(bottom of the reservoir). Also, be sure your vent line is not plugged.

 

[wcolt45]

New m/c,with a remote reservoir

 

[poppop]

What DH says is correct. I have had trouble with more than one. I also had one that the push rod lock came loose and the rod extended itself with use until the piston could not return all the way home which blocked the return hole.

Just saw your reply above. Did you adjust the push rod for the correct free play in the petal??

 

[wcolt45]

I've replaced all rubber hoses ,m/c ,rebuilt airpak,installed remote reservoir,rebuilt wheel cylinders,earlier today checked m/c by removing cap and pushing pedal down and i can see fluid coming back through the tiny hole in m/c,running out of things to check

 

[hoop]

How is your brake pedal return spring?

 

[wcolt45]

Just adjusted the rod at m/c ,thought that may be it ,but not,spring returns pedal to floorboard

 

[hoop]

With all of that checked I would say your brakes are way out of adjustment then.

 

[wcolt45]

Major adj ,as per tm,but why are they locking up?fluid isnt returning past the airpak

 

[stancanpara]

I've been having the EXACT same problem with my since I bought it 6 years ago..... still trying to figure it out.... what's the fix?

 

[hoop]

Stan you are close....I have to do an engine swap next week. I would be willing to look and help the week after.

 

[doghead]

Is your new remote res vented? it needs to be.

I would say the problem must be in the airpack air valve.

You can remove the pipe plug in the back of the booster. Put you finger over the hole and see if air builds some. If you notice any build up(when you let your finger off), your air valve is leaking.

 

[wcolt45]

Wanna swing north and fix mine too? Im thinking its got to be the airpak,after pumping the brakes,or for a short drive they're dragging then locked

 

[stancanpara]

Stan you are close....I have to do an engine swap next week. I would be willing to look and help the week after.

Heck yeah!!!! PM me! Where are you located? Do you need help with the engine swap?

 

[doghead]

When you rebuilt the airpack, did you follow the rebuild proceedure outlined in the TM?

 

[wcolt45]

Yes i did,thought it went well.

 

[wcolt45]

What part of the airpak controls fluid pressure ?I mean if i were to disassemble it again what parts need to come off to see why it went release pressure back to m/c? hopefully i wont have to take it completely apart.

 

[Boatcarpenter]

When you rebuilt the airpack did you come across this warning? I'm not sure what difference it makes in the operation of the airpack personally, but it must make a difference.
BC

 

[wcolt45]

Yep,caught that one ,just wandering if the springs kinked or something during reassembly

 

[doghead]

Pull the plug and see if air is building in the can. If it is, your air control valve is leaking.