View Full Version : HELP! anyone know the difference between REAR C5 and LS1 caliper brackets?
I just got my rear disc brakes they were supposed to be rear 98-02 F body/LS1 disc brakes with 12" rotors and integral ebrake drum. I have the correct backing plates with built in drums already. WHen i put them on the caliper is not spaced corrrectly over the rotor, in fact they are spaced so far inwards the the caliper abutement is touching the outside face of the rotor, and on the inside of the rotor there is like a 3/8" gap. I believe i might have the wrong caliper abutements. I am thinking they sent me C5 rear brakes, if this is so, can i just swap out the caliper abutments and still use the calipers and rotors i have? do the C5 and LS1 rear brakes use different caliper abutements. THanks a lot, this will really clear some stuff up!
Q ship
10-01-2004, 06:53 PM
Are the rotors fully seated against the axle? Is the dimension from housing flange to axle flange 2.75"? From what I know(which ain't much) the Vette abutments use larger bolts to attach to the backing plates. HTH, good luck.
i haven't measure the axle flange, from which points on the axle/backingplate flange? it used a 12MM bolt seemed to fit in the abutment hole just fine
dennis68
10-01-2004, 08:25 PM
Yes Yodi, the C5 and LS1 calipers and abutments are different. Not very much, just enough so that you can't use the C5 calipers with the LS1 backing plates. You can use the C5 calipers as cores to get the Ls1 calipers though.
we are talking about the back brakes here correct? if so Dennis's theory would make perfect sense
dennis68
10-01-2004, 09:10 PM
Yes, rears. Yodi, I'll get you part number for the rebuilds-I found some that for the LS1 that include abutments, calipers, pads, and hardware for like 75.00/ea +core.
I did the same thing, bought all C5 stuff and then found out the rears won't work with the LS1 backing plates.
do you think that you could use LS1 backing plates, LS1 abutments, C5 rotors and C5 calipers?that way all they will have to send me is new abutments, thanks for the info tons!!!!!
Chevyman73
10-02-2004, 03:45 AM
Yody if you are interested I think I still have a set of LS1 abutments. I was gathering the stuff for the swap and kinda scrapped my plans and decided to use Outlaw 4 piston calipers front and rear. Let me know.
Q ship
10-02-2004, 06:15 AM
do you think that you could use LS1 backing plates, LS1 abutments, C5 rotors and C5 calipers?that way all they will have to send me is new abutments, thanks for the info tons!!!!!
Can't use C5 rotors with LS1 abutments, wrong offset on rotors. That may be your issue. Use ALL LS1 parts.
blazer4corners
10-03-2004, 12:36 AM
dont the c5's have bigger back rotors than the ls1? if so if hes using ls1 rotors and c5 abutments the caliper would be to far out not hitting the rotor and being to far in towards the axle
Q ship
10-03-2004, 06:43 AM
2000 C5 rotors: OD 305 mm, ht 48.5 mm.
2000 Camaro rotors: OD 305 mm, ht 62 mm.
Same outside diameter (roughly 12 inch), differant "hat height". Additionally the C5 rotors have curved vanes (differant part left and right), the Camaro rotors are straight vane.
Yody, are you trying to use C5 rotors?
From what I know, the C5/Camaro calipers will swap between abutments, but the abutment/backing plate/rotor must be from the same car.
great info, the problem is i ordered LS1 everythign and it won't work, i believe they sent me C5 everything, so i am trying to find out what needs to be sent back. thanks!
Q ship
10-03-2004, 07:53 PM
Here's a link (http://members.fbody.com/86firebird/ls1/ls1brakes.htm) with pics of the Camaro stuff.
Can anyone do me a huge favor? i am still having probs. i Do have the correct calipers and rotors and backing plates. But the calipers will stilll not mount correctly!!!! They need to come towards the outside of the car by about 1/2"! The rotors i have do have the straight vanes. Can anyone get the casting number off of their LS1 abutment?? it is a # like this (X)###-###(X) it is on the outside of the abutemnt on top fo the bar that goes under the caliper, i need to see if i have the correct abutments or not. Thanks!!!!!!!!!!
dennis68
10-05-2004, 03:57 PM
I'll get you Corvette numbers tomorrow Yodi, at least then you can confirm that DON'T have the C5 stuff.
thanks! also I measured my axles and they are the same exact length as my stock axles and the distance from the mounting surface of the axle to the mounting surface of the backing plate flange is 2.75 just like qship said, so i took my stuff to my friends house and tried them on his 70 RS 12 bolt and go the same exact thing!!
Chevyman73
10-06-2004, 09:14 AM
Hey Yody! Here's the LS1 bracket numbers I have. Looking at the top it has..............
23H9 K332-130C S
On the bottom it has .........
BTR S4
Hope it helps you! :fingersx:
man, that is the same thing i got!!! What could be going on here?????? i will post pictures later so far i have verified this;
correct caliper and abutment
correct rotors
correct backing plate
axles are same length as stock
8.5 10 bolt
tried it on stock 12 bolt with same results
what could be going on here?? No one else seemed to of had these problems? i will post pictures later. thanks again!
dennis68
10-06-2004, 11:15 AM
Yodi, my C5 abutments are stamped K332-123C
Chevyman73
10-07-2004, 04:04 AM
Hey Yody! Don't know if it will help you any, but here it is anyway. I measured a stock LS1 rear axle this morning when I got to the yard. The spacing from the mounting face of the caliper bracket to the axle face is 2 7/16" Might want to double check yours just to be safe. :icon996:
thanks i will check that!
I measured my axles and they came out right also. I have no idea whats going on here, maybe its the backing plate?? I measured from teh axle to the front mounting flange on the backing plate, not where the caliper attaches but the side closest to the outside of the car and got 2 3/4" additioanlly if I space the bracket about 1/4" out from the axle flange it mounts correctly??? I dont' want to have to use washers!! can anyone provide me with casting #'s off of the correct backing plates? thanks
I measured with a dial indicator and the abutment needs to come out .230 for the abutment to be positioned correctly. Also if anyone could check when looking at the back of the rotor it does not appear that the tin dust shield on the backing plate protrudes into the rear of the rotor at all it seems that it should be protruding into the back of the rotor some, also if i look carefully you can see just a tiny bit of the ebrake pad sticking out fo the rotor. I am thinking maybe something is weird with my rearend? also can someone measure the distance from the front of the rotor surface where the brake pad contacts to the wheel mounting surface on the rotor? thanks
Q ship
10-07-2004, 07:15 PM
Are you sure the rotor is sitting correctly against the axle face? I ask because sometimes the axle flange needs to be turned down to fit inside the rotor. It's just a WAG at this point, I will be interested to see what the final answer is.
i am pretty sure the axle is fitting right, i will double check that though, anoither good point. At this point i am thinking maybe i have a mismachined rotor of some sort? I am thinking of machining an adapter to mount and space out the backing plate. can anyone give me some rotor hat measurements and so forth?
HILROD
10-08-2004, 07:58 AM
Are the rotors sitting flush on the flanges? I think you have to turn down the O.D. of the axle flamge to I believe 5.90?
Chevyman73
10-08-2004, 02:26 PM
Hey Yody! It's me you friendly neighborhood junk merchant! :naughty: Here's the backing plate numbers on an LS1 axle....
K360-0760
And a couple pics that may help too.....
http://66.70.234.198/forum/attachment.php?attachmentid=902&stc=1
LS1 w rotor.
http://66.70.234.198/forum/attachment.php?attachmentid=903&stc=1
LS1 wo rotor.
http://66.70.234.198/forum/attachment.php?attachmentid=&stc=1
LS1 backing.JPG
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