Brake upgrade Problem

**architect7** · 05-09-2009, 05:20 PM

Alright all. I've been working on a C6 Z06 brake upgrade for a while now and not that I'm "all done"... I'm having problems bleeding the brakes. We did the passenger side first (only swapped the fronts) and then the drivers side but still having problems. We just got done spending about two hours bleeding them and we’re still having problems. Now when we press down on the pedal we’re no longer getting bubbles in the line off the caliper but the petal still will go all the way to the floor with the bleeders closed on the calipers. And when I start the car, the petal falls to the floor with just the weight of my foot and will never pump up. The master cylinder is full and the bleeders are pointing up. I’m at a loss and have no idea what’s going on… we changed the lines and hooked the calipers up last weekend but are just now bleeding them. Could air have gotten to the back lines somehow or into the ABS box? Anyone with any clue of what might be going on would really help me out if you chimed in!

Thanks all!!!

**Mr. Luos** · 05-09-2009, 05:35 PM

Anytime any air gets into the system...you should bleed all 4 corners.

**architect7** · 05-09-2009, 05:46 PM

Originally Posted by Mr. Luos

Anytime any air gets into the system...you should bleed all 4 corners.

it seems like there is a TON of air in the system still or something just way wrong. even with a little air in the system, with the car running, the petal shouldn't just fall with the weight of my foot should it?

**pajeff02** · 05-09-2009, 05:50 PM

Originally Posted by Mr. Luos

Anytime any air gets into the system...you should bleed all 4 corners.

+1 Always start at the back right wheel and work your way closer to the master cylinder. It's good to get the old fluid out of the lines anyway. Are you pedal pumping or using a Mighty-Vac? Also, any chance you sucked your reservoir down too far while bleeding and pulled air into the master cylinder?

**architect7** · 05-09-2009, 06:23 PM

Originally Posted by pajeff02

+1 Always start at the back right wheel and work your way closer to the master cylinder. It's good to get the old fluid out of the lines anyway. Are you pedal pumping or using a Mighty-Vac? Also, any chance you sucked your reservoir down too far while bleeding and pulled air into the master cylinder?

we're pumping the pedal and no, we watched the cylinder very carefully... this is quite the puzzler and am beginning to regret doing the swap. we've had tons of little oddities that normally wouldn't have come up...

**pajeff02** · 05-10-2009, 04:09 AM

Run down to Autozone and drop $30 on the base model Mighty Vac. You can thank me later.

**Too Fast** · 05-10-2009, 04:21 AM

Originally Posted by pajeff02

Run down to Autozone and drop $30 on the base model Mighty Vac. You can thank me later.

Yup. Start bleeding the farthest from the master cylinder, RR then LR then RF then LF. You got air in there somehow, to do a good flush/bleed you will use about a qt. total of fluid.

Also, there is the possibilty that the mc got ruined while you were doing your intial bleed with foot power. The mc was working in a specific spot internally before you did any brake work, when you bled the system it travelled to a spot it normally did not, if there was any corrosion, inside the bore, that can ruin the seal. I've had it happen to customers cars. That would explain the pedal to the floor/no air/no leaks.

**bene** · 05-10-2009, 05:16 AM

post some pic when your done!

**architect7** · 05-10-2009, 09:45 AM

Originally Posted by Too Fast

Yup. Start bleeding the farthest from the master cylinder, RR then LR then RF then LF. You got air in there somehow, to do a good flush/bleed you will use about a qt. total of fluid.

Also, there is the possibilty that the mc got ruined while you were doing your intial bleed with foot power. The mc was working in a specific spot internally before you did any brake work, when you bled the system it travelled to a spot it normally did not, if there was any corrosion, inside the bore, that can ruin the seal. I've had it happen to customers cars. That would explain the pedal to the floor/no air/no leaks.

no chance that the air traveled into the ABS block and that could be causing the problem? it does seem like it could be the master cylinder but the car is an '02 with 13k miles on it... I'm not sure where to go from here...

Thanks for the pointers.

**Wesman** · 05-10-2009, 02:32 PM

Originally Posted by architect7

no chance that the air traveled into the ABS block and that could be causing the problem? it does seem like it could be the master cylinder but the car is an '02 with 13k miles on it... I'm not sure where to go from here...

Thanks for the pointers.

Does your car have traction control??

If it does, I remember reading that a GM Tech II is required to bleed the brakes properly - which could at least be part of your issue.

**JoshieDoom** · 05-10-2009, 02:39 PM

Originally Posted by Wesman

Does your car have traction control??

If it does, I remember reading that a GM Tech II is required to bleed the brakes properly - which could at least be part of your issue.

Even if it doesnt have TCS/ASR you have to have a tech II to get the air outta the ABS block.

TCS is more of accelerator pedal thing then it is ABS.

**pajeff02** · 05-10-2009, 06:15 PM

Originally Posted by Wesman

Does your car have traction control??

If it does, I remember reading that a GM Tech II is required to bleed the brakes properly - which could at least be part of your issue.

Originally Posted by JoshieDoom

Even if it doesnt have TCS/ASR you have to have a tech II to get the air outta the ABS block.

TCS is more of accelerator pedal thing then it is ABS.

Can you guys explain this a little better? And isn't the Tech II the godawful expensive scanner that only the Goodwrench boys have?

**Wesman** · 05-11-2009, 09:01 AM

Originally Posted by pajeff02

Can you guys explain this a little better? And isn't the Tech II the godawful expensive scanner that only the Goodwrench boys have?

Its the GM scantool that the dealers use. And yes, they are very expensive.

However, if you bring the car to the dealer, they could use the scan tool and bleed the brakes for you. How much they would charge, I don't know.

**architect7** · 05-11-2009, 09:47 AM

oh man.... well... i almost didn't even write this post because I had a severe L.D. moment this weekend with the brakes. As you've seen with the original post, I've done a C6 Z06 six piston front brake upgrade and have been having trouble getting pedal response after the bleeding. That was Saturday. Sunday, we re-bled everything, starting with the rear... then while using the mighty vac on the front right side, I noticed something that I wish I had seen 24 hours earlier... a second bleed valve!!! yes, and I don't know why I didn't think of it to begin with. having three pistons on the inside and 3 on the outside, I should have known there would be two bleed valves. so, 5 minutes later and two more bleeds on the inside valve of the front calipers, and the car was moving out of the garage for the first time in quite a while... now it's backed in and I've got one last rear wheel well to work on to get the last stock C6 Z06 19x12 inch wheel to fit. THEN I'LL BE DONE!!! but on the drivers side, I'm afraid I may have to remove the fuel line so I can heat the ribs on the inner fender well and beat them in to make room for the wheels. I think the fuel line is close to that area. I'll keep everyone posted on the progress... it's been much more trouble than I had expected!!!

**Wesman** · 05-11-2009, 10:03 AM

Originally Posted by architect7

oh man.... well... i almost didn't even write this post because I had a sever L.D. moment this weekend with the brakes. As you've seen with the original post, I've done a C6 Z06 six piston front brake upgrade and have been having trouble getting pedal response after the bleeding. That was Saturday. Sunday, we re-bled everything, starting with the rear... then while using the mighty vac on the front right side, I noticed something that I wish I had seen 24 hours earlier... a second bleed valve!!! yes, and I don't know why I didn't think of it to begin with. having three pistons on the inside and 3 on the outside, I should have known there would be two bleed valves. so, 5 minutes later and two more bleeds on the inside valve of the front calipers, and the car was moving out of the garage for the first time in quite a while... now it's backed in and I've got one last rear wheel well to work on to get the last stock C6 Z06 19x12 inch wheel to fit. THEN I'LL BE DONE!!! but on the drivers side, I'm afraid I may have to remove the fuel line so I can heat the ribs on the inner fender well and beat them in to make room for the wheels. I think the fuel line is close to that area. I'll keep everyone posted on the progress... it's been much more trouble than I had expected!!!

Glad to hear you found the problem!!

Please post pics when you are done, I'd love to see your setup.

What offset are you running on the wheels, and did you need wheel spacers for the spokes to clear the calipers??

**architect7** · 05-11-2009, 10:11 AM

Originally Posted by Wesman

Glad to hear you found the problem!!

Please post pics when you are done, I'd love to see your setup.

What offset are you running on the wheels, and did you need wheel spacers for the spokes to clear the calipers??

I actually ran all the calcs on our stock wheels vs the new Z06 wheels and what I found out was basically, the front wheels are almost the exact same for the front spacing and just .47" more on the backspacing and there's plenty of room up front for those wheels. so the fronts worked perfectly without any mods or spacers. (although I did completely remove my stock spindles and cut up some LT1's to go on there. that way i can put all my stock stuff back on someday if I feel the need). the rear 12 inch wheels added around 3/4" of an inch to the front spacing and about 2.25 inches to the backspacing for the 12" wide wheels. that's required A LOT OF WORK! I've completely removed my bumpstomps and am heating and hammering in the inner fenderwell to make everything fit. I had to buy custome LCA's to make some room (was going to do anyway so not too big of a deal) and when the other rear wheel is on, I'll slap on my adjustable PHB and center it all up and hopefully still won't need spacers on the rear. it'll be sweet to have 325's on 12" wide wheels with no spacers back there. one side is on and working... just one left!

**pajeff02** · 05-11-2009, 12:08 PM

Originally Posted by architect7

oh man.... well... i almost didn't even write this post because I had a sever L.D. moment this weekend with the brakes. As you've seen with the original post, I've done a C6 Z06 six piston front brake upgrade and have been having trouble getting pedal response after the bleeding. That was Saturday. Sunday, we re-bled everything, starting with the rear... then while using the mighty vac on the front right side, I noticed something that I wish I had seen 24 hours earlier... a second bleed valve!!! yes, and I don't know why I didn't think of it to begin with. having three pistons on the inside and 3 on the outside, I should have known there would be two bleed valves. so, 5 minutes later and two more bleeds on the inside valve of the front calipers, and the car was moving out of the garage for the first time in quite a while... now it's backed in and I've got one last rear wheel well to work on to get the last stock C6 Z06 19x12 inch wheel to fit. THEN I'LL BE DONE!!! but on the drivers side, I'm afraid I may have to remove the fuel line so I can heat the ribs on the inner fender well and beat them in to make room for the wheels. I think the fuel line is close to that area. I'll keep everyone posted on the progress... it's been much more trouble than I had expected!!!

I'm real happy to know that I am not the only one on here who does stuff like that. The Mighty Vac is a great tool if you never had one before. I will never "pump bleed" again. Glad it worked out for you -- now post up some pics for us!

**Too Fast** · 05-14-2009, 02:19 PM

Glad to see you found the other bleeder valve on that front caliper. If you don't have a lot of experience with this stuff, I can see how it would be easy to miss! If I don't have stuff in front of me, it's hard to diagnose. If I were there, I would've seen the other bleeder valve and could've gotten you going real quick!

**architect7** · 05-14-2009, 05:21 PM

Originally Posted by Too Fast

Glad to see you found the other bleeder valve on that front caliper. If you don't have a lot of experience with this stuff, I can see how it would be easy to miss! If I don't have stuff in front of me, it's hard to diagnose. If I were there, I would've seen the other bleeder valve and could've gotten you going real quick!

yeah, it's just one of those things that completely escaped me and slipped my mind. if i had been thinking, this thread would never have been started. i compare it to when you're looking for something on your work bench for 10 minutes and cannot find it... then your buddy comes over and walks right to it and it was in front of your face the entire time right in the center of the bench... it was there.... i just didn't see the freaking thing!!!

**architect7** · 05-19-2009, 05:44 PM

Originally Posted by bene

post some pic when your done!

ALRIGHT EVERYONE.... car is done. all that's left is to install my Adj. PHB and get it aligned. (I also will be fabing my own LCA's. the aftermarket ones I've installed are making far too much noise for my taste.) but I'll get it all cleaned up and get some pictures up this week. wheels are 18x9.5 fronts with 285's and 19x12 out back with 325's. NO SPACERS!!! a ton of work that i really wouldn't recommend unless you're nuts like me and don't mind TONS of work getting to that finish line... but I'm happy with the finished product.