has anyone ever compared the caliper brackets of an H-body to those of a W-body? im just curious, they might be surprisingly similar ya never know..GM made a lot of things almost the same, yet different....i for one never wouldve thought that the caliper brackets and calipers from an F-body could be swapped onto a W-body with relative ease(it can be done, and might be a project if i ever get aftermarket rims)...so anything is possible...i have a set of W-body caliper brackets in case anyone wants pics or measurements or anything...I know the stock Bonneville wheels dont have much clearance, but it might be something the guys and gals with aftermarket wheels could do? just a thought...

Look up the part numbers on GMPD for starters.

Here'* a list of cars that came with 12" brakes;

Buick Le Sabre 2000 - 2004
Buick Park Avenue 1997 - 2004
Buick Riviera 1997 - 1999
Cadillac DeVille/Concours 1997 - 2004
Cadillac Eldorado 1992 - 2002
Cadillac Seville 1997 - 2002
Chevrolet Impala 2000 - 2004
Chevrolet Monte Carlo 2000 - 2004
Oldsmobile Aurora 1997 - 2003
Oldsmobile Intrigue 1998 - 1999
Pontiac Bonneville 2000 - 2002

From this we can see a mix of body styles with the same brakes. The spindle (knuckle) assembies are not all the same but many of the brake components are shared in typical GM fashion.

Also, as you mentioned, the F-Body calipers and brackets can be mounted on the W-Body spindles simply by drilling and tapping the brakets for the W-Body calpier bolts (M14).

Cheers,

UMMMM interesting the 97-99 PA came with the 12"ers...and they share the same breaking system as we do.....

according to GMPD, the Park Avenue uses a different caliper than the other H-body cars after 96.

The 97 and later PAs use a different caliper, the same one used by some other W-bodys and a mix of other cars, G-bodies and the like.

the part number for the front-left caliper of a 97 PA is 18046196


and Will, GMPD does not list a part # for the caliper bracket on any H-body Bonneville that i could find.

the part # for the caliper brackets used by 12 inch W cars and a couple Caddys oddly enough is 18029829...this tells me that although the PA has 12 inch rotors, it may still use the H-body type bracket, and then have a different caliper?

Dont we have some PA owners here that could check this out?

92 to 99 Bonnevilles have the caliper bracket integrated into the spindle (knuckle). It'* not possible to change the brake assembley with changing the spindle.

As an aside, I had my contact at GM lay out on the counter the front hub/bearing assemblies from a 97 Bonnevile, a 2000 Bonneville and a 1999 GTP...they were all exactly the same dimensions though I have no idea about differences in Traction Control/ABS systems.

Cheers,

Actually, I got curious about my brake size once and measured the rotors, and they came out to be 13" front and rear.
Maybe the Ultra has bigger brakes, or I may be recalling wrong.
But the steering knuckle and thus the mounting points for the caliper bracket, is the same on all these cars, so the caliper bracket will swap to any of them. In fact I beleive you can also use the front brakes from the last gen F-body or Vette on our cars as well.(This may be my next upgrade)

Gonneville as for your rotors, id say theyre probably 12 inchers....its hard to say though really...GMPD can be a little flaky on things at times, if you search for a rotor for a 98 PA you will get part # 18026591, which is shared on some 00+ w-bodies that i was under the impression came stock with 12 inchers...if you pull up a rotor for a 99 Camaro, which had 12 inchers stock, you get part # 18060640 which was used on some of the same cars that the previous part # returned....to complicate matters further, the part # listed on ClubGP as a 12 inch rotor is 18021015....its just craziness, we have 2, possibly 3, rotors all the same bolt pattern and size, but with 3 different part #*?! whats the difference?

and as for caliper brackets, we seem to be getting mixed information, Foghorn says the entire spindle must be changed in order to swap in larger brackets, whereas Gonneville says that brackets can be swapped freely....anyone care to comment on this?

im just trying to perhaps stir up some interest in this, as ive never seen anyone here interested all that highly in it before, but maybe i just missed it, and my Bonneville didnt stop all that well and liked to warp rotors, so upgrading the brakes would be a good thing to do.

the 00+ SLEs and SSEis have larger brakes than the SEs, which share the same brakes as a GTP

The caliper bracket is integrated in the spindle for 92-99 Bonnevilles. The 2000+ Bonnevilles have the aluminum spindle and seperate caliper bracket with either 11" or 12" disks depending on trim though they all share the same caliper.

If the 97+ PA came with 12" brakes then it did NOT have the same spindles the Bonneville had in the same year. It seems for 97 to 99 there were many different combinations of brakes for the H & W Bodies.

The 97 to 03 GTP only came with 11" front brakes while the 2000+ Impala had 12" brakes. Of course certain year Intrigues (W Body) had the Autobahn brake package that included 12" front disks.

The 2004 Comp G GTPs had 12" front disks while the Bonneville GXP has 13" front brakes.

By and large, those with aluminum spindles can interchange some brakes, those with the cast iron spindles are up the creak.

It would be an exelent upgrade for someone like me to change to aluminum spindles and calipers from the current cast iron. The weight savings would also make a nice handling improvement by reducing the unsprung weight.

Cheers,