hey Guys,

I've been fighting weak stopping brakes for a few months now, the car is an 86 base with T2 5 lug conversion. The pedal feels great, very solid, the car just doesn't stop fast at all when you hammer the brakes. I replaced the pads front and back with hawk HP's i put stainless steal brake lines front and back. and made sure each caliper was working properly and wasn't siezed.

I figured maybe the booster wasn't supplying any extra force, and found that it couldn't hold a vacumme. So i just bought a used T2 booster and master cylinder, to replace the N/A units on the car. I installed it, the master cylinder was dry, i filled it, and blead the brakes using a speed bleeding pressure bleader system that presurizes the master cylinder to force fluid through the lines.

Now the brakes feel just as bad, if not worse than before. is it possiable that i should have bench bled the master cylinder, and that there is still air trapped in the master, but not in the lines?

anything else i could be over looking here?

thanks so much in advance

 

I'm assuming that you replaced the old 1 piston caliper with the 4 piston caliper when you did the T2 swap? I know it's not much advice, but when it comes to breaks, I usually don't do the bleeding myself and just take it to a reputable mechanic to bleed the brakes for me.

I might take it to one and see what he says. Maybe someone else will have more advice for you. =\ Sorry I cant help more then that.

 

Did you get brake fluid on the pads and or rotors? That would definitely cause poor braking.

The best way to bleed the brakes is to just have someone help you out by pumping the brake pedal, I don't think it is necessary in any way to pay someone to bleed your brakes unless you are in a bind or something. Also there shouldn't be any need to bench bleed the master cylinder.

Also some performance pads seem to not work at all, and its not because they suck its because they have not gotten hot yet.

 

I've never bench bled a MC and never had any problem (and in the past few weeks I've installed five different MC's in my car).
If you think there might be air in the cylinder you can try this...
Have an assistant in the car and as he/she (it?) slowly presses the pedal down, crack one of the line fittings on the cylinder and retighten before the pedal is released.
A rag around the fitting will help contain any fluid that will escape.
Repeat for all three fittings.

Well, it's possible that either the new (to you) booster or MC is also bad.
Not likely, but possible.

As noted, new pads- especially "performance" pads- require a bedding in procedure.
Go to Hawk's website and see what they recommend.

Finally, when you installed the new pads, did you turn the rotors?
If not, you should have.

 

yea i had brand new rotors installed and i followed the bedding procedures exactly. i'm gonna try the old fashioned way to bleed them tonight and report the results back

 

I'm at a loss. I have no clue what to do next with these brakes. After re bleding them the pedal feels very stiff, but still I really have to push considerably for them to grab. even when measuring the rotor temps after hard braking the fronts and rears left and right side match, which makes me think the calipers are fine or i'd have uneven rotor heating.

what can i look into next. I've never felt a 4 pot FC braking ability before. I've read its good, but to me my FB's brakes were way better. This cant be right

 

Doesn't sound like it.

With your symptoms the first thing I'd suspect would be the booster.
You do have the check valve in the vacuum line, right?

If you pull the vac line from the booster nipple, you should hear the vacuum escape.
Now, blowing from the newly released end, you should be able to blow through the valve but not suck through it.

See what happens.

 

Make sure the rubber line that goes to the booster isn't kinked either. I replaced something on my old N/A and pushed a metal line a little out of my way and it kinked the line. When I drove the car the pedal was stiff, but there was very little braking. I found it and unkinked the line and it was fine.

 

The check valve seems to be working as it should, its air tight, but its a check valve from a honda. I did not however hear any vaccume escape when i took off the hose.

I'm gonna put a vacumme pump on it, and see what happens

 

Origin doesn't matter...a check valve is a check valve.