Mushy brakes..

[91CoupeMike]

Been fighting a mushy brake pedal for a while now.

If I press the pedal when coming to a stop, it doesnt build pressure, it starts to slow down and eventually the pedal will go to the floor. If I'm already stopped and I press the pedal it has pressure then it bleeds off and the pedal goes down.

I don't have any (or major) vaccum leaks, the booster still holds about 2 full pedals of vaccum after the car is off. I don't see it pissing brake fluid anywhere, and I'm not loosing fluid.

I've narrowed it down, air in the lines or a bad master cylinder.

What else should I look for?

[jnobles06]

or the old rubber lines are flexing under hydraulic pressure and are worn out.

[80coupe]

bleed them prob air in the line!

[Baron Von Crowder]

bleed them prob air in the line!

do this, and then replace the master cyl that is letting fluid bypass, then do that again.

[91CoupeMike]

I'll change the master cyl and bleed the system, flush the fluid and replace the lines.

It needs it anyhow. 20 year old brake hoses can only go so far...

[BlueCoupeRedVert]

Get stainless steel braided lines.

[racrguy]

Everything said above. Master cylinder is junk, and replace all the rubber parts in the brake system.

[majorownage]

Mike might drop .001 with the brake system removed. I say just cut it all out. Every bit helps.

[AMJ]

Mike might drop .001 with the brake system removed. I say just cut it all out. Every bit helps.

fuck it who needs brakes???

[Trick Pony]

I had the same symptoms on my '85 GT. If it's got no leaks AND you haven't recently opened up the system to where air could have gotten in, it's going to be your master cylinder. I replaced mine and it fixed it.

[Grape]

if the brakes pump up while the car is sitting still, yet go away while driving, check front wheel bearings...............pad knock back

[garycrist]

Master or a leak...

[91CoupeMike]

if the brakes pump up while the car is sitting still, yet go away while driving, check front wheel bearings...............pad knock back

Pad knock back?

[dville_gt]

Pad knock back?

bad wheel bearing allows the rotor to wobble and push the pad/piston back into it's bore so as soon as you go to press the brakes you are simply taking up the slack vs squeezing the rotor... (or at least that is my understanding)

[91CoupeMike]

bad wheel bearing allows the rotor to wobble and push the pad/piston back into it's bore so as soon as you go to press the brakes you are simply taking up the slack vs squeezing the rotor... (or at least that is my understanding)

My cars brakes rattle, and this is what's happening.

I replaced the wheel bearings not long ago.

I replaced the rotors, bearings and seals.

It started to rattle again, I assumed it was the outer pads holding clamp, because to get my front runners on I had to beat them flat.

So I replaced the pads, repacked the bearings and it was good for about a week, and it all started again.

What am I doing wrong? The only thing I can think of is maybe the spindle nut isn't on tight enough? I get it hand tight then make about a half turn or so till it feels snug and the rotor doesn't wobble by hand.

Do I need to crank it down more?