Need Brake Help ASAP!

Hello all, this is Nick (93formulalt1), I'm helping Ben get the 'bird back on the road. . . And we are having some problems. The car is Ben's '97 Firebird 3.8 V6 Auto. It has a posi rear end, 4 wheel anti-lock disc brakes, and we replaced the brake hoses with stainless braided lines at all four wheels. We bled the rear brakes, but ran into some problems with the fronts, so Ben replaced both front calipers with remanufactured units from Advance. We got those installed, and re-bled the front brakes.

The brake pedal feels GREAT with the car off, but as soon as the car is started, the pressure drops. The pedal doesn't quite go all the way to the floor, but the pedal is spongy, and it doesn't feel nearly as stiff as it should. We tried re-bleeding the brakes (all four corners), and got the same result. We are both at a loss as to what could be causing the problems with the pedal feel, so we are looking for any suggestions we can get. Any ideas? Thanks in advance!

[1BADAIR]

any gravel roads around?
make sure the wheels are actually stopping
then go drive it. cycle the abs if you can

[93formulalt1]

any gravel roads around?
make sure the wheels are actually stopping
then go drive it. cycle the abs if you can

We haven't even driven the car yet, Ben's afraid something will happen to it, and with the poor pedal feel, I can't say I blame him.

[kyleozzie]

any gravel roads around?
make sure the wheels are actually stopping
then go drive it. cycle the abs if you can

yeah i have had a few cars that were close to the same situation, and i just drove them and they firmed up alot.. hope yours is the same!!

[prorac1]

Yeah, do as Larry said and cycle the ABS a couple of times on a dirt road and that should do the trick. I believe it gets the air bubbles out of the ABS unit. Eric L

[93formulalt1]

Yeah, do as Larry said and cycle the ABS a couple of times on a dirt road and that should do the trick. I believe it gets the air bubbles out of the ABS unit. Eric L

Just talked to Ben, he got everything put back together, and took the car for a drive. He said the car stops just fine, it's just that the pedal still doesn't feel right. I told him to take it down a gravel road and lock up the brakes to cycle the ABS (as per Larry's instructions), he said he'll give it a shot. If that doesn't fix it, he's going to have the mechanics at work take a look at it and see if they can't figure it out.

He also mentioned the "ABS INOP" light popped on for a little bit while he was driving it, which leads me to believe that there is an air bubble or two in the ABS unit.

[1BADAIR]

after the abs cycles rebleed the system

[98blackbeauty]

there are 2 bleed valves on the front of the abs unit did you bleed them before you did the front and rear brakes?

[93formulalt1]

there are 2 bleed valves on the front of the abs unit did you bleed them before you did the front and rear brakes?

Yes we did. He drove the car in to work today to have the mechanic take a look at it, if they don't find anything wrong with it, we'll re-bleed them tomorrow.

[93formulalt1]

Welp, the rear caliper bolts were loose. Ben drove the car to work, one of the bolts came all the way out while he was on his way in, and when the tech pulled the wheel off, the caliper fell off. That's why it's important to DOUBLE CHECK EVERYTHING. He said the brakes are MUCH better now, just waiting for the final word on what exactly was wrong and how it feels going down the road.

[phoenix_rising]

Hey everybody. I just got home. Car is driving good. Looks like that loose caliper bolt caused all the trouble. We replaced all 4 caliper bracket bolts. While we were at it I got a lifetime alignment and GOT MY FREAKIN WINDSHIELD WIPERS WORKING!!!! After 5 years for those of you keeping track. There are still a few things that are not "perfect" like the ABS Inop light coming on once in a while. It was a long day but I am glad it is over. I have tomorrow off and I plan on driving!!!:wooot: Thanks for all the ideas guys.