stiff brake pedal

[steve40]

figure i'd copy my post from ls1tech over, see if anyone can provide any insight.....

Just installed a SJM abs delete kit. Replaced most of the brake lines in doing this, can't find any pinches or kinks in the lines. Also overhauled all calipers and the sliders are free allowing the calipers to move. The brakes bled good, can't find any more air left lines. I'm finding the pedal very stiff, its hard to get the pedal down, just to push the button in on the shift. When driving the car, its extremely hard to get it to stop. I'm out of ideas on where to look. The motor is fresh, so not really sure what vacuum its pulling. Either way, its a very noticeable difference to my dd even with the engines off.

car is a 97 trans am

[Kwazrollinz28]

bleed them brake lines it was my problem it was a pain.

[steve40]

well bled them again tonight...didn't get a chance to take it out to a parking lot yet....seems better. but not quite sure its 100%, my thinking is something is blocking the line to rear, the fronts push much more fluid.

[Kwazrollinz28]

No theres just a LOTTTT of air in the rear it took me a whole week to get it perfect, you have to bleed it, test drive it, Get it hot, bleed it, Redo. get the point?

[Jay_rich]

No theres just a LOTTTT of air in the rear it took me a whole week to get it perfect, you have to bleed it, test drive it, Get it hot, bleed it, Redo. get the point?

His problem with this is he just got it running and he is working out the tune and doesnt have insurance so kinda hard to do!

Jay

[steve40]

well it went for a lil drive yesterday....brakes still suck, bleed almost a 1L bottle thru, and remade the last 2 lines in the rear. only parts around from last time it ran, the 4 calipers, brake booster and all flex lines.

my friend did say when bleeding the brakes and working on the rears, when opening the bleeder, the pedal would go down, but not all the way, but in the front it would drop to the floor with ease.

i'm lost. i know the line lock and proportioning valve work, and have no leaks anywhere.

[meissen]

Steve - what your friend is experiencing is (I believe) normal... atleast I know that when I was bleeding the brakes after putting in the brand new brake lines that my dad commented the brake pedal wouldn't go down all the way.

Doesn't explain why it's so stiff, though.

[steve40]

Steve - what your friend is experiencing is (I believe) normal... atleast I know that when I was bleeding the brakes after putting in the brand new brake lines that my dad commented the brake pedal wouldn't go down all the way.

Doesn't explain why it's so stiff, though.

ok, well that is good to know....my car has sat for over a year and a half now. things i was familiar with are long gone!

i'm pretty sure the problem has to be somewhere in the rear brakes, the fronts seem to hold the car with the line lock after a few pumps. might just throw some cash out and buy new rear calipers, maybe the pistons are sticking, they are the original ones that came with the car.

[steve40]

well even more fun so far....remade the rest of the remaining brake lines, bled them, no luck, borrowed a vac bleeder, still no luck, i now have 2 new rear calipers hanging up drying from paint, should get them on tomorrow, and then its fingers crossed.

[meissen]

Good luck, Steve. Please keep us updated - I'm really intrigued to hear what the cause could be. Any way to take the calipers you have on there off without disconnecting the brake line to see if the caliper is sticking?

[steve40]

Good luck, Steve. Please keep us updated - I'm really intrigued to hear what the cause could be. Any way to take the calipers you have on there off without disconnecting the brake line to see if the caliper is sticking?

i read the haynes manual and pulled one apart. pretty easy to pull apart, but i doubt you could pull the piston out with the line hooked up. not sure if what i saw was good or bad. after talking to my buddy who is a mechanic. said it was either 2 things, sticking caliper or collapsed flex line, all look to be fine, so hopefully i guess right!

[98blackbeauty]

Normally when you have any air you have the opposite problem, soft mushy petal not hard and hard to stop. I would check your vacuumn line to engine, then go buy some plugs disconnect rear line at front insert plug see if just the front react properly. then do the back at the rear end you can plug one the the other at the t block. Each time you'll need to bleed air out. 1 other thought is if I remember correctly the main rear feed line is bigger tubing than the 2 sides from the t block. Did you measure and use the correct size tubing since you mention you made the lines.

[steve40]

our thinking is that a caliper is sticking and preventing the pedal to travel further. all the lines are same size as the factory ones. so the main feed to the rear is bigger than the line to each wheel. the fronts work fine, they are making enough pressure to hold the car with the line lock on.

[98blackbeauty]

Have you went over the lines to check for kinks/ I don't believe a collapsed line would stay collapsed with the pressure. has to be blockage or stuck piston. is the an adjustment for the proportioning valve in the delete kit.

[meissen]

If you put your foot on the brake, can someone still turn the rear rotors/tires?