Upgraded to 12 inch Brakes installed on car

[dizzle1]

I found a 01 3.8 red monte carlo at the JY with the 12inch brakes intact and not messed with. The rotors were smooth and a fraction of a inch smaller than my near new 11inch originals. I looked at the dust boots they were good and took the bolts/screws, it came out at $46. Rotors were a little rusty but I used air tool to sand the lug section and braked them in and now they look clean.

The thing I noticed when removing the right passenger bracket was the additional thick washers that came off my caliper bracket bolts so I had to use them, the monte's went in too deep.

Looking at the 11inch brakes behind the rim didn't look cool at all but changing it to the 12's really gave it a sporty agressive look that I like.

Braking is more confident at all speeds more on highway, the front wheels lock easier at city speeds. Give's you a premium car feeling with stronger and shorter stopping distances.

The upgrade is really cool mod that I like, now only if my anit-lock was fixed I should see its full potential.

Things that I took note of during the installation
1. The brake lines strecthed out a little more
2. I looked at my spare tire size number on the trunk label and its a 15inch
3. Saw no matching RPO codes on my trunk sticker like JB9, JA9
4. Had to bleed front brakes

It will work on all stock intrigue rims but not the spare you need to get a 16inch to complete it from cars with 12inch rotors like impala or monte carlo.

Sticker with a bunch of 3 digit codes the RPO code label.
JA9- Heavy Duty Brakes (12 inch)
JB9- Light Duty Brakes (11 inch)

[LittleHoov]

Im curious as to why the brake lines stretched? Did you let the calipers hang from them?

Also, the brake lines shouldn't have needed to bled, because at no point do you ever open the system to air, again, that's definitely strange.


Glad you like it though, and you should really pursue getting the proper size spare, its something I havent done yet. The bigger spare I thought I got later turned out to be for the wrong car entirely (JY screwed up). Ive only had to do it once, but its a pain to have to change two tires for one flat.

Get that ABS fixed so you can take better advantage of that stopping powa!

[Hoppy2]

Do you not have to change at least the calipers to compliment the bigger diameter rotors? This would conclude the need to bleed the brakes.

[LittleHoov]

No the calipers do not need to be changed, the calipers are the same between 11 and 12 inch models, its only the caliper brackets that are different.

The brackets move the caliper out farther to compliment the bigger rotors. Nothing else really needs to be changed except brackets and rotors.

[Hoppy2]

Hmm, That seems like an easy brake changeover then. What models can you get the brakes and brackets from? Unfortunately I had to put new front brakes on my car a year ago and don't want to change them till they are worn out.

Are there bigger brakes for the rear too? Or only the front.

[aghopkins]

Originally Posted by Hoppy2

Hmm, That seems like an easy brake changeover then. What models can you get the brakes and brackets from? Unfortunately I had to put new front brakes on my car a year ago and don't want to change them till they are worn out.

Are there bigger brakes for the rear too? Or only the front.

The JA9 (Heavy Duty) brake package only included larger rotors for the front. The backs were the same. Even the OSV Intrigue with the 13 inch front rotors still had just 11's on the back if I'm not mistaken. You might could find a way to upgrade the back ones with the same mounting brackets that you would get for the front but I doubt it would make a significant difference. You would probably end up wasting money and time by going ahead with it.

As far as the cars that are equipped with these brakes I don't remember the years but Cadillac Sevilles, Chevy Impalas and Monte Carlos came with this package. I think the caddys were from the late 90's and the Chevy's were from the 2000-2003 range. Also any 98-99 Intrigue with the JA9 brake package would work. Just check the RPO code on the inside of the trunk lid to verify that it had JA9 brakes rather than JB9 (Light duty).

[Hoppy2]

What about price for new pads and rotors. Are they more expensive for the 12's vs the 11's?

I'm not sure if I am going to bother with the upgrade, the existing brakes work well and I rarely get to the wrecking yard any more. If I do find them I will probably pick them up. Aside from the rotors, are the pads the same? Do I only need the bracket and rotors for the upgrade?

[aghopkins]

Originally Posted by Hoppy2

What about price for new pads and rotors. Are they more expensive for the 12's vs the 11's?

I'm not sure if I am going to bother with the upgrade, the existing brakes work well and I rarely get to the wrecking yard any more. If I do find them I will probably pick them up. Aside from the rotors, are the pads the same? Do I only need the bracket and rotors for the upgrade?

The 12 inchers are slightly more expensive (5-10 bucks more depending on where you are getting them from). Pads are essentially the same. The only neccessary changes are the mounting brackets and the rotors themselves. I changed out my pads when I did this upgrade a couple of weeks ago but only because the old ones were badly worn. I would highly recommend getting the brackets from the boneyard if you make it out there rather than ordering them from GM. They are outrageously expensive (around 70 bucks each for new).

[phewop118]

I really want to do the 12 inch upgrade. Wbodystore has a kit that has dual-piston calipers (I think it's the F-body upgrade), but it costs nearly $300. I would do the JA9 upgrade, but I've heard that the 12" rotors with single piston calipers actually warp faster than the 11" rotors due to more heat being held in the rotor and the pressure of the caliper not being dispersed very evenly.

[dizzle1]

Originally Posted by LittleHoov

Im curious as to why the brake lines stretched? Did you let the calipers hang from them?

Also, the brake lines shouldn't have needed to bled, because at no point do you ever open the system to air, again, that's definitely strange.

The caliper brackets move the caliper outwards by 1/2 an inch the brake lines will move more outward also. So If you steer completely to the left look at the slack on the line its tighter than before same for the right when right car was jacked up too, I'll post pics.

They were hung on the strut and I used a long garbage tier incase it slipped

The reason for bleeding is when I removed the caliper from the 11 inch rotor, I used a jumbo flathead to free the pads so I can remove it as I'm pushing the piston(s) in, so it built air pressure within the system and then needs to be bled out.

Intrigue brake codes JA9 12inch, JB9 11inch
1. Cars with 12inch rotors 5x115
2. Caliper brackets?
3. Longer brake lines?
4. Calipers?
5. Stock spare tire fitment?
Autozone.com on Valucraft / Brake Rotor - Front
Rotor part #55034B Heavy duty brakes (JA9 option code)
Rotor part #55036B Light duty brakes (JB9 option code)
Searched Autozone part #'s
1. 12ich rotors were standard in these cars with the Same part #'s, bolt patterns
1997-2005 Buick Park Avenue
2000-2005 Chevy Impala
2000-2005 Chevy Monte Carlo
1997-2004 Cadillac Deville
1997-2002 Cadillac Eldorado
1998-2002 Cadillac Seville
1997-2003 Oldsmobile Aurora 2000 is N/A
1998-1999 Oldsmobile Inrigue Autobahn package Rare find JY
1998-1999 Oldsmobile LSS
Pontiac
2. Caliper brackets?
2000-2005 Chevy Impala
2000-2005 Chevy Monte Carlo
3. Longer brake lines?
But its working check the slack on the JY cars
4. Calipers?
2000-2005 Chevy Impala
2000-2005 Chevy Monte Carlo
1998-2002 Oldsmobie intrigue
5. Spare tire size?
T125/70D15
Need 16inch from impala or monte carlo
gmpartsdirect.com
Caliper mounting brackets part # 18029829
Rotor part # 18021015
Same as in the link http://www.clubgp.com/cgi-asp/mods.asp?modid=3
Tools needed JY and DIY
Bring a measuring tape
Ratchet set w 15mm Socket bit, extensions
Breaker Bar
Look at the grandprix forums and aftermarket sites for further info

[av8rcapt]

Hi Guys- I'm new to the forum, but not new to working on my own car. I did this upgrade on my '98 Intrigue about 3 years ago and it has been awesome. The rotors don't warp right away like they used to - and I am a 'spirited' driver! I went about doing it a little differently though. Back when I did it, I bought Raybestos rotors through Advanced Auto, they were only $5 more each. The brackets were a little different. I got those by ordering reman calipers for the heavy duty system from another parts place ( sorry, i can't recall- maybe from the partsamerica website? ), they came with the mounting brackets (as advertised) and, with the core refund, came to roughly $38 each. Otherwise, every other front end part is the same. Also, spend the time to paint the calipers because they are very visible and look great all painted up. One other tip, go to GM and buy the new copper washers for the brake lines. Aftermarket ones are hit or miss for leaks.

The only downside to this I learned the hard way, when it was 10 degrees outside. If you get a flat front, the spare will not fit over the caliper. You have to take and stick the spare on a rear, then take that rear tire and put it on the front.

-Happy Braking!

[dizzle1]

Here's the Pics

[dizzle1]

Just got the 16inch spare from another montecarlo for $12 so that plus 46 is now $58. The brake upgrade is complete and the Styrofoam thing that held the 15inch spare was actually made for the 16inch spare it held it tighter from the bottom.

[sparcx]

A couple questions about this mod...

I see mention that the brake lines stretch out a little more. Has that caused any additional problems since you guys did this mod?

Also... Do you think changing the rotors would affect how the stability control system (PCS) works on my car? Would you think there are any possible issues with that system? (I'm guessing not, but thought i'd ask)

I'm thinking of rolling this mod in with the next brake job as I'd like a little more stopping power.

[dizzle1]

No the brake lines are fine that’s only when the wheels are off the ground and the wheel is steered all the way but its not actually stretching the hose. The hose just bends more.

Heres something I made, didn't know where to throw all this so here it is

GM W-body 2nd Gen 97-05
Buick Century, Buick Regal, Chevrolet Impala, Chevrolet Monte Carlo, Oldsmobile Intrigue, Pontiac Grand Prix

A popular mod on W-body's are bigger front brakes over the stock 11's that did not provide sufficient stopping distances or feel. The Oldsmobile Intrigue was first to get the factory GM W platform brake upgrade setup with the Autobahn package. The intrigue's that had the package were seen with bigger 12inch front brakes that were sought after for replacement parts that can help upgrade other W-body's. With the release of the 00 Chevy Impala and Chevy Monte Carlo parts became more abundant as these cars came standard with 12inch brakes.

Stage 1 and 2 will work with factory 16inch alloy wheels if car was equipped with a 15inch spare that also would need to be changed to 16. Stage 3 requires use of 17inch wheel owners can go to 18 if they like. By using a 245/45/18 series wheel and tire package it will help accommodate bigger rotors and increase handling and braking performance. Wheels that are 19inch would be the ideal look on the cars but they are nearly impossible to find for the 5x115 bolt pattern.

Front brakes
Stage1 12inch rotors, caliper brackets
Stage2 12inch rotors, F-body caliper brackets w 12mm bolts, F-body dual piston calipers and pads, 4 crush washers
Stage3 13inch rotors, caliper brackets, dual piston calipers and pads, longer brake lines, From 05-08 GP GXP 5.3 V8

Stage1 is the simplest one to do because you'll still retain the original caliper and only have to get longer brackets to hold the calipers, rotors are available at any auto parts store it’s a direct bolt on. The 98-02 F-body GM F platform Chevy Camaro and Pontiac Firebird cars came standard with 16inch alloys V-6 or V-8 but its rotors will not fit since they use a 5x120 bolt pattern. Stage2 requires use of 4 copper crush washers to fill the gap in the spindle while retaining use of F-body 12mm caliper bracket bolts. The threads are only on the caliper bracket, the crush washers go in the spindle to secure the position of the bolts. Another way of doing this is by getting the caliper brackets tapped to fit 14mm bolts that come originally on a W-body car this requires precision machining and is only a one time deal. The use of copper crush washer allows for a more fast and simple swap without any custom fabrication and still performs as it should. Also one could assume that any caliper and bracket that can go on a 98-02 F-body will fit a 2nd Gen W-body. The problem is the biggest rotors available in the 5x115 bolt pattern only come on Grand Prix GXP’s 05-08.

Rear brakes
Stage1 12inch rotors, caliper brackets, From 05-08 GP GXP 5.3 V8

Rear brakes can be upgraded to 12inches although they still remain solid and are not vented discs. Prices are steep and isn't really in demand. More than 60 percent of the weight on these cars hangs over the front wheels.

Performance
With just the 12inch upgrade braking distances from 60mph were reduced from 132ft to 126ft. Shorter stopping distances are even more noticeable from higher speeds and pressure of pedal feedback needs less effort. Use of F-body dual piston calipers should reduce that distance to under 120ft. How come no one has mentioned the idea of brake cooling ducts, it really is something to be considered has anyone done it even custom?

Appearance
In order to have cleaner wheels use of longer life ceramic brake pads are popular since they dust less but may contribute to warping of rotors? Owners may paint their calipers and brackets with high heat paint and also use stainless steel braided brake lines for a clean finish. The stock brakes look as if something was just there to help stop the car and look kind of small behind a 16inch rim. That alone didn't inspire great braking performance when it was compared to cars that competed with it and especially to the eyes of people overlooking the car. When the 12inch upgrade is done the gap between the rim is filled up leaving a sportier appearance, and dual piston calipers will leave a stellar look when done nicely.