Umrswimr

I replaced the stock pads with PFC-Z pads and replaced the front rotors at the same time since they had hot spots and some pad buildup ("warping")... After I installed the pads and used my handy-dandy vaccuum bleeder, the pedal pressure sucked. I've since bled a whole bottle of fluid through the system using the standard pedal bleeding system (see below) and the pedal is still spongy.

Check my prcedure o make sure I didn't do anything stupid:

1) Remove master cyl cap.
2) remove caliper/pads/rotors (front)
3) Using a C clamp, compress the caliper pistons back into the caliper.
4) Install metal backing plate on pads, install pads, re-assemble, bleed using vacuum bleeder. Add brake fluid as necessary to keep reservior full. IT NEVER WENT DRY.
5) Repeat for rear pads, sans the replacement rotors. Bleed using vacuum bleeder. For the rear bleeding, I kept getting air bubbles. I believe it was leaking from around the bleeder bolt and the vacuum was pulling the air in...

Took the car for a brief test drive and it was obvious that the pedal was not very firm. Probably the crappy seal mentioned in #5. So I went back to the standard pedal bleeding. Attach the bleeder hose/cup to the valve, crack the valve open, and depress the pedal a few times to force fluid out. I followed the bleeding procedure (RR, LR, RF, LF) and the pedal was firm with the car off. Once I started the car, I could tell the pedal was not firm. A quick drive confirms this.

I've run out of brake fluid (again) so I figured I'd ask the experts... Did I do something wrong here? I've done brakes on several cars without incident, but this one won't firm up.... Any ideas?

BLKTA

Make sure you pump the brake pedal until it's completely firm with the engine off to drain any vacuum left. When I switched brake lines I had to bleede the system several times to get it right. Also, did you seat the pads correctly? It will take a little time to set the pads.

IM QUIKR

I've heard the vacuum bleeding can cause cavitation (air bubble formation) in the brake lines. Pressure bleeding is preferred. You may have induced air bubbles in the ABS which can't be bled out by pedal pumping. I hope I'm wrong.

LoneStarFRC

Since you're going for more fluid anyway, get some speed bleeders while you're there. You only need 1/4 turn (open) when bleeding. BTW, try not to get too frisky when pushing the pedal. I've seen some folks pump very rapidly and this is not a good idea.
drcoffee I hope your wrong about the need for him getting any air out of the abs system since that's going to take a Tech II scan tool to cycle the abs solenoids, and that usually translates to a dealer visit.
BTW, if you replaced your flexible lines with stainless, double check your torque at the caliper and the frame side too.
Keep us posted.

AU N EGL

That is correct dr coffee. Pressure bleeding is the best method for non Tech-II dealers/ ppl

personnly I do not use speed bleeders and have many friends who have removed them as they were too messy. All it takes is a 10 mm open end and tagon hose that fits over the bleed valve and drains into an old soda bottle. Remeber dont let the any air back in.

Good Luck

Umrswimr

Ahh, crap... I really hope that's not the case. So basically pressure bleed the heck out of them and hope it fixes the problem... If not, it's off to the dealer?

Any idea how much that stupid visit will cost?

IM QUIKR

Personally, I'd never go back to the chevy stealership(typo). Find a good local shop that works on vettes or even a quality brake shop. I don't understand what makes a chevette mechanic qualified to work on Vettes. But that shoulder patch(which should say "Mr. average Wrench") doesn't make them any smarter.

Umrswimr

Well, I went out today and bled all four wheels again with no success- the pedal is still not very firm. I was only barely able to engage the ABS while driving and when it did engage, it was a very strange sloshing/pulsating sound, not the usual "thud-thud-thud" that it usually makes. So it looks like I need to take this puppy in and have it looked at.

Stupid vacuum bleeder! It claimed it was safe for ABS systems!

Mike Mercury

was it the hand-pump variety? If so, they supposedly don't create the vaccum level required to foam the fluid.

Umrswimr

I had about 35 inHG on it...

IM QUIKR

Yea that equates to ~17 PSI. That would cause bubbles.

Dave68

Actually, each of the many of the Chev. dealerships around here have at least one designated Corvette mechanic on duty. When I needed to have my diff gasket replaced, I had to wait an extra day before bringing my car in because the "Corvette mechanic" was out sick and the dealership would not let the "Mr. average wrench" work on a Corvette. The same guy did a great job replacing the power door lock module and column lock actuator, so I have no doubt that he knows what he's doing.

Richin Chicago

We are going to have to agree to disagree on this one. I am at the other extreme. I have quite a few clubmembers that installed speedbleeders and have had nothing but great results.

6spd89

I thought i read on the forum that bleeding goes like this...
ignition off-----RR,LR,RF,LF
IGNITION ON----RR,LR,RF,LF
igntion off------RR,LR,RF,LF
From what i recall,you have to have the ABS"on" at some pt. during the bleeding process.My .02
Matt

Mike Mercury

good gawd! I hope you were wearing protective goggles and steel toed shoes...

AU N EGL

Vaccum bleeders can and do cause cavitaion on the brake lines i.e. seperate brake fluid and cause air bubbles and a soft peddle.

The Motive power bleeder with 10 to 12 psi is more then enough pressure to PUSH brake fluid though the lines.

Richin Chicago

I've read that before but never seen it in a GM service manual. I never have done the ignition and always have a very high pedal with just one bleed. I don't think having the ABS on wil do anything if you can't pulse it. You need a Tech II to do that.

BTW any car from 01 on requires a RR LF LR RF bleed due to electronic proportioning.

Jim 47

Lots of good advice, but, have you bedded in the pads/rotors yet???

The soft pedal feel could be coming from poorly bedded pads.

Jim

IM QUIKR

I'm glad your experience thus far has been positive.

Well here's my experience with the "designated Corvette Mechanic", I dropped off the car for a trany leak. 1-2 days they tell me. 5 days later I go to pick it up and they let me drive off the lot with a rubbing/grinding sound and thought nothing of it. In fact the mechanic acknowledged the sound but said he could not find it. dumb azz! So I pull back around and tell them to fix it. 2 days later, I get it back. When I get home I do an admirering once around the car look see and find that the "designated Corvette Mechanic" Lifted my car from the rocker panel.

Because it's Friday I have to wait until Monday to take it back so the "designated Corvette mechanic" can defend himself. Guess what? He denies that he did it. I go nuts. The manager realized he was at fault especially when I showed him photos (date stamped) just days before the fiasco began and there was no damage present. But let's not stop there. There were clips missing that run along the tunnel plate. Wires leading to the transmission were stripped bare probably because they were not unclipped before lowering the unit. My right Z06 brake duct now was rubbing on the tire. The freshly brush painted brake calipers were chipped badly. And when all was done. A two day trany seal became a 4 week disaster. And to add insult to injury, the repair to the rocker panel has left a weird image on the paint like a plastic bag stuck to it. Now, we are not talking about some podunk dealership. This is the Horizon Chevrolet in Naperville. No, no you can go back to your dealership all you want. I've had all I can stomach.

Umrswimr

Took it to the dealer... Explained what I did and they agreed to check it out.

An hour later, the mechanic came back in:

F 'em. I'm calling my nearest Midas shop. Once again, should have listened to Dr Coffee.