Paul Riccioli Jr

iTrader: (1)

I finally got to install my C5 brakes last night and this morning. I have some issues though.

The driver side rotor is rubbing the inside top corner of the abutment really bad. Almost to the point where I can't turn the wheel by hand. The passenger side is pretty much ok...there's a little drag at one spot on the rotor...must be a little untrue?

The only idea I have for the driver side is that maybe I didn't grind enough off of the spindle and it's making the custom bracket crooked? Other than that I don't have any ideas.

Has anyone else had this problem? Any other ideas?

Also I'm having trouble bleeding all the air out of the system. I went through almost a quart and a half of brake fluid and my pedal goes about 3/4 the way down with no resistance then gets firm. Any tricks for this one?

Any help is greatly appreciated.

ebmiller88

iTrader: (7)

Yes, I've had the same problem on a C5 kit I just did, adn before that on a LS1 kit for a Monte Carlo SS. The issue is that not all spindles are cast exactly the same and sometimes they just don't "bolt up" without a hitch. ONe boss may be taller than the other one. I really advise all you guys doing kits to test fit them if you can before you install them on the car.

You can do a number of things to fix the problem. First one, and the only one I recommend, is to remove the bracket and remove the amount of metal you need off the upper bolt boss, reassemble the bracket on the spindle and try it again. I DO NOT recommend grinding ANYTHING off the GM brake parts...once you do this, they are useless to anyone else should you try to sell them or change your mind and upgrade to something else, IE-Wilwood. Should you decide to do the grinding on the brake parts, you can take a flat file to the inside of the abutment and take off the metal you need to until you get rid of the rub. You can also take a bit of height off the abutment bosses and accomplish the same thing.

As for the bleeding, just changing out the front brakes shouldn't take that much fluid unless you totally drained your master and prop, but that still seems like a lot. If you have the time, try gravity bleeding the system. Attach some small tygon tubing to each bleeder valve, open the bleeder, and just let the system fill and drain until you get clear fluid out of the hose, just don't empty the master your you'll have to start all over again.

I've only had two rubbing issues like you described and both happened when I sent a kit out in pieces, and didn't fit it up beforehand due to time conflicts of the kit's user. I won't do that again.

Good luck!

Ed

Paul Riccioli Jr

iTrader: (1)

Thanks for the reply. I will definitely try grinding down the boss in the spindle a little bit...I should be able to put the tap back into it after....or I'll get another bolt and just put it in the hole and grind around it....then take it out after...doesn't matter if the threads on it get chewed up after.

If I do decide to grind the abutment bosses I should try to do them evenly I assume? This way the pads apply even pressure still?

How much clearance should I look for between the rotor and abutment? I'm assuming not much since those parts probably don't really expand.

ebmiller88

iTrader: (7)

Only remove metal from the boss that is giving you trouble, not both, and make sure your rotor is seated fully on the hub. As for clearance, it will usually be around 1/8"-3/16" and that's about it. The rotor needs to be in the center of the slot in the abutment, not much room but even.

Ed

Paul Riccioli Jr

iTrader: (1)

Thanks. I think I'm going to try taking metal off the abutment boss...that seems like the easier fix and if I screw it up it's a lot cheaper for a new abutment than a new spindle. Hopefully tomorrow I'll be able to work on it.

If I just use the bolt to clean up the threads after that should be fine right? That's such an odd tap to find that I don't know if I'll have another choice.

The rotor is drfinitely on the hub square....I used a rubber mallet to seat it and then took it off and did it again and then put the wheel on and tightened all the lugs down and it's still doing it.

I guess I'll check to see what's up with the passenger side as well. If it's rubbing in one spot ever so lightly I'm guessing the rotor has some slight runout? Do you think it's worth it to have it turned a hair?

Paul Riccioli Jr

iTrader: (1)

Ok I think I have enough clearance now. I used a flat file like you suggested EB and took off material from the bosses on the abutments. I'm going to try to bleed the system out again now. I'm going to give your idea of gravity bleeding a try...I've never done it before but we'll see if it helps.

I'll keep everyone posted.