Rear Disc Brake Upgrade issue?

OK...today I tried to assemble my parts for the New Upgrade to rear Disc brakes. The passenger side assembled with no problems, but was a bit tight. I then tried to assemble the driver's side, and there was NO way it would fit, as it was way too tight! I measure the rotor thickness at @ 1" and a shade under 1/16th inch? Maybe I should check for different thicknesses of pads??? I ordered the calipers from CPP out of Cali and they are for a 85 Caddy! Rotors from NAPA are listed for a 85 Caddy as well???
Any ideas anyone??


As you can see...there is absolutely no clearance when I try to load the rotor??
B.W.

Okay, the firebird rotors are almost exactly an inch thick.
Is the small nub on the caliper side pad riding out of the notches on the piston? That looks alot tighter than what I have going, Wish I had a part number for the pads the kit is using, Its got to be a difference in pads all the other dimensions are fixed in iron.

Digz wrote:
Is the small nub on the caliper side pad riding out of the notches on the piston?

Can you explain?
B.W.

Im wishing I had a picture of it now. towards the outside of the rotor on the metal part of the pad there is a small nub that seats into notches on the caliper piston, I'm just going by what was on mine and in noway am I speaking as an expert. it will tip the padout at the top about a 16th or more of an inch. I have assumed and I may be wrong, that this keeps the caliper piston from turning as the E-brake functions. BTW it is recommended to use the E brake regularly to keep the caliper in adjustment.
and it must be used to get the caliper in position before you bleed the brakes.
if there are notches in the caliper piston it should have the nub on the inner pad. My pads were loose enough that Im hoping the piston clocks itself into place when I adjust becaus I couldnt get it to line up easily. If we need some pics I can disassemble it and take some.
Okay I went back to one of Dons posts and swiped this pic, notice the notches in the piston.

OK...I know what you mean now! Thanks!
B.W.

Try backing off the ebrake manually, that could be the problem.

B.W., sorry I was out of pocket all day and of little help.

Later,
Rip

Thanks Don...I was thinking about doing just that!!
B.W.

Yeah, did a dry fit on mine with the caddy plates and the 15" centerline's. and it's going to be reel close, maybe too close!!

Dan I know what you mean about "Close"! I even placed a 3/16th spacer on the rotor and it still just touches the caliper! I will switch to a 1/4" one I just ordered from CPP, that should take care of that??

B.W.

Thinking the spacer idea will work but if not I would have to turn down the rotors as well to adjust the calipers. Not enough space in there.

Whats hitting on the centerlines Dan? what part of the wheel I mean, I had to put 1/2 inch on the Keystones to clear ,but they had that wide tire relief in the outer steel rim, I would have thought the centerlines would be a smooth rim into the lug flange area?
I have 2 pairs of 5/16" spacers if anybody needs them, multi lug pattern. Also wondering what B.W found as the cure for tight rotors?

They are smooth. The calipers just hit the wheel when I tighten the lugs. I took BvrWally's advice and ordered some 1/4" spacers. Pretty sure that will do it. But if not I will turn down the rotors 1/4" and re-adjust the caliper's like Don suggested.