Foxbody brake questions need some help

[my89notchback]

Having trouble getting all the air out if my brake lines. I bought a power bleeder which worked, but when you remove it and replace the master cylinder cover, the pedal softens up again. Granted it pumps up after one cycle of the pedal, but still not right.

There are no leaks in the system. When the system is pressurized with the power bleeder, there is no decrease in gauge pressure. I'm stumped? I've also changed masters twice, changed front calipers, rear wheel cylinders and lines a few times chasing this.

1) Should there be any pre-load on the pedal pushrod? I have it touching when the pedal is at rest, but no load on it?

2) should the master cylinder lid have a vent on each side (this is a metal clamp style) or should it seal tight?

If anyone wants to take a swing at this thing, I'll pay you. I don't want to piss the summer away chasing this.

Chris
810-429-6446

[90SuperchargedLx]

First off dont use the power bleeder have a friend help you do it the old school way. keep bleeding it it took me a long time to get my brakes right when I did my rear disk swap with the 93 cobra master cylinder on my fox. also is the pedal soft to the point where it goes to the floor when you push it?

[Beigg]

Do you have the piston caliper pad plates in place? If those think plates are missing, it can result in a soft pedal. It is basically allowing the piston to push through the pad if that barrier of metal is mia.

Try gravity bleeding the system?

[Beigg]

Where are you located?

[mustangmike6996]

Jack up the rear and bleed the rear then do the same to the front. Then do it again with the car on the ground.


Sounds like the pressure bleeder is compressing the air bubble and when you release the pressure it expands and causes a soft feel.

Try a vacuum bleeder as well as having someone pump and hold the brake pedal.

Do right rear, left rear, right front, left front in that order. Furthest to closest for bleeding.

I have seen some people run a bit of preload on the MC pushrod. I cant remember the spec for the fox. I do know that the last fox I did a brake bleed on took forever!

[my89notchback]

Goodrich. I'll pay for gas.

[PHAT83]

rear drum or rear disc brakes are the rears adjusted ?

[my89notchback]

rear drum or rear disc brakes are the rears adjusted ?

It has the rear drums. They are adjusted out.

[my89notchback]

TTT. Nobody??

@Mike;

I'll try raising the rear of the car later today.

[OldbutNew]

MustangMike nailed it. Do NOT rely on the pressure bleeder as the do-all, end-all.
Go to the tried-and-true manual bleed. RR, LR, RF, LF. In that order.