Budget 4 Piston Caliper Swap

[CorradoKev]

So after nearly six months of researching an inexpensive 4 piston caliper swap for the front of our Sonic chassis, I finally stumbled across the fact that the Cadillac CTS/ATS with the J55 Brembo brake caliper option are a direct fit to the Sonic spindle IF you've already performed the Encore brake upgrade. After sourcing the calipers for $150 for the pair, test fitment revealed the need for at least a 15mm spacer for the factory wheel to clear the caliper. I used a 20mm spacer which nearly aligns the wheel flush with the fender and adds a bit of extra space between the wheel and caliper. The only hurdle left after that discovery was finding a rotor of the correct diameter as the Encore rotors left nearly 10mm of pad material overhanging the edge of the rotor. The only rotor with BOTH the correct height AND diameter belongs to the Buick Cascada and at the time of my research, it was only available through GM directly. However, the bolt pattern for the Cascada is not the same as the Sonic, so the rotors needed to be re-drilled by a machinist. I replaced the original GM pads with EBC Yellowstuff pads to match my rear setup. The copper crush washers for the brake lines must be replaced during the swap with thicker ones as the Sonic brake lines attachment points where the banjo bolt connects are just a tad thinner than the Cadillac's. I bled all four calipers after the install as well as the clutch to ensure fresh brake fluid throughout the system.
Suffice it to say, the braking difference is substantial when needed. Everyday driving is no different than the Encore setup. There's absolutely no brake fade after performing this swap. And for the first time with my sticky Michelin Pilot Super Sports, I've been able to fully appreciate their grip during a panic stop. The only additional change I'm going to perform is swapping out to steel lines to further improve the feel.
As with any modification, especially with the brakes, proceed at your own risk. Do not attempt this or any other modification without the proper tools and knowledge of the braking system. I've added a few pictures of the setup. Please let me know if you have any questions.

 

[hammrdwn510]

You pick up the calipers used? eBay?

 

[CorradoKev]

Yes hammrdwn510. They wanted $100 each initially, but they accepted my offer of $75 each. The caliper is very common across different vehicle makes and even brand new aren't as expensive as I thought they'd be.

 

[carsNskis]

I'm so glad someone pioneered this, thank you. I've been scoping the same calipers, just not wanting to spend the money to find out they don't fit... Great work

What did you do for the rear? I'd like to run brembo in the back too (mostly for cosmetics), but single piston with a cable e brake fitting in gm works is hard to spec

 

[CorradoKev]

Hey carNskis! I upgraded the rears to EBC slotted rotors with EBC Yellowstuff pads. With nearly 77K miles, I'd only replaced the rear pads once prior to this upgrade. The front pads, however, I'd replaced three times and routinely needed to replace the rotors from warping about every 20K miles. That's what prompted me to research this upgrade in the first place. I was tired of warping the front rotors. Although a rear swap to larger calipers, pads, and rotors would look great, my research determined that there isn't anything in the GM parts bin that would be nearly as easy a swap as the fronts were. The larger front rotors should help dissipate heat more effectively and so far with about 7K on this new setup, very little wear is present on the pads or rotors.

 

[sonix13]

So after nearly six months of researching an inexpensive 4 piston caliper swap for the front of our Sonic chassis, I finally stumbled across the fact that the Cadillac CTS/ATS with the J55 Brembo brake caliper option are a direct fit to the Sonic spindle IF you've already performed the Encore brake upgrade. After sourcing the calipers for $150 for the pair, test fitment revealed the need for at least a 15mm spacer for the factory wheel to clear the caliper. I used a 20mm spacer which nearly aligns the wheel flush with the fender and adds a bit of extra space between the wheel and caliper. The only hurdle left after that discovery was finding a rotor of the correct diameter as the Encore rotors left nearly 10mm of pad material overhanging the edge of the rotor. The only rotor with BOTH the correct height AND diameter belongs to the Buick Cascada and at the time of my research, it was only available through GM directly. However, the bolt pattern for the Cascada is not the same as the Sonic, so the rotors needed to be re-drilled by a machinist. I replaced the original GM pads with EBC Yellowstuff pads to match my rear setup. The copper crush washers for the brake lines must be replaced during the swap with thicker ones as the Sonic brake lines attachment points where the banjo bolt connects are just a tad thinner than the Cadillac's. I bled all four calipers after the install as well as the clutch to ensure fresh brake fluid throughout the system.
Suffice it to say, the braking difference is substantial when needed. Everyday driving is no different than the Encore setup. There's absolutely no brake fade after performing this swap. And for the first time with my sticky Michelin Pilot Super Sports, I've been able to fully appreciate their grip during a panic stop. The only additional change I'm going to perform is swapping out to steel lines to further improve the feel.
As with any modification, especially with the brakes, proceed at your own risk. Do not attempt this or any other modification without the proper tools and knowledge of the braking system. I've added a few pictures of the setup. Please let me know if you have any questions.

So this only works if you've a;ready done the encore swap?

 

[CorradoKev]

So this only works if you've a;ready done the encore swap?

Yes, only because the holes for the caliper mounting bolts need to be the larger 14mm size. That's the only additional step prior to the swap.

 

[minitrucking02]

I was going to look into a quad piston fixed caliper for the sonic, but after doing the research and discovering the Camaro brake swap, I opted for the direct bolt on:]

Cheaper, no drilling necessary, still performs great.

 

[hammrdwn510]

I was going to look into a quad piston fixed caliper for the sonic, but after doing the research and discovering the Camaro brake swap, I opted for the direct bolt on:]

Cheaper, no drilling necessary, still performs great.

:troll: but do they look as cool :trollolololol:

 

[minitrucking02]

I would love to have a massive caliper but, way too much work.

 

[CorradoKev]

I would love to have a massive caliper but, way too much work.

I also looked at the Camaro swap before opting to go with the four piston Cadillac caliper instead. The reason I wanted to upgrade the front brakes in the first place wasn't for aesthetics, but rather because of the frequent warping of the front brake rotors. With the amount of miles I drive regularly for my job, the type of stop and go traffic that I'm typically in, and the intense heat found here in South Florida, I simply wanted to stop having to change the front rotors from warpage. I'd already upgraded to the Encore pads and rotors with no discernible improvement in the amount of time before the rotors needed replacement. With this new setup, specifically due to the dramatically increased size of the rotor, the amount of heat generated from stopping is dissipated more effectively reducing the likelihood of rotor warpage. As an added bonus, the Brembo caliper is lighter than the Sonic caliper.

 

[SonicBRO]

I like the write up thanks for sharing, when you added the wheel spacers how much poke out has affected the wheel fender line? do you know if the calipers are all the same per different years as well with the rotors? last question, as far as the copper crush washer for the brake line goes, does any larger crush washer do the job? or do you need to have a specific part for this application to work?

I'M most likely following suit for I just desire everything to go smooth so Its pain free.

-SonicBro

 

[CorradoKev]

I like the write up thanks for sharing, when you added the wheel spacers how much poke out has affected the wheel fender line? do you know if the calipers are all the same per different years as well with the rotors? last question, as far as the copper crush washer for the brake line goes, does any larger crush washer do the job? or do you need to have a specific part for this application to work?

I'M most likely following suit for I just desire everything to go smooth so Its pain free.

-SonicBro

The wheels are just under flush with these spacers on. (I'll have to snap a picture for you later to see.) I'm not certain of the years GM used that caliper on the CTS, but it's been used in the GM lineup for some time. The rotor is only found on the Cascada which has only been out for a year. As for the crush washer, I simply used the thickest one I could find in an assortment pack I purchased.

 

[crazyTERMINATR]

Great research on the upgrade! I might have to look into this as a winter project. With people saying this is too much work I just want to make sure I am reading this right. All that is needed for this swap is to drill out the caliper bracket holes to 14mm and redrill the rotors to the sonic bolt pattern? Fabricating and machining doesn't scare me as I can do it all at work.

 

[CorradoKev]

Great research on the upgrade! I might have to look into this as a winter project. With people saying this is too much work I just want to make sure I am reading this right. All that is needed for this swap is to drill out the caliper bracket holes to 14mm and redrill the rotors to the sonic bolt pattern? Fabricating and machining doesn't scare me as I can do it all at work.

Those two steps are the only bit of machining and drilling that need to be done. It all bolts up after that.

 

[sw2low]

While searching ebay for a set of camaro calipers i noticed an abundance of camaro SS brembro fixed calipers. I confident they'll bolt on, since they are replacements for std camaros. My concern is the rotor offset needed. I would assume they use the standard camaro front rotor. I dont want to run wheel spacers.

Anyone have some knowledge on this before i start matching up model numbers on rockauto?

Thanks

 

[carsNskis]

I've been scouring our parts trash to see if a set gets junked. Now that I'm in the service dept ill be watching for camaro brake jobs like a hawk!

[emoji593][emoji809][emoji472]

 

[CorradoKev]

While searching ebay for a set of camaro calipers i noticed an abundance of camaro SS brembro fixed calipers. I confident they'll bolt on, since they are replacements for std camaros. My concern is the rotor offset needed. I would assume they use the standard camaro front rotor. I dont want to run wheel spacers.

Anyone have some knowledge on this before i start matching up model numbers on rockauto?

Thanks

Due to the larger overall width of the four piston caliper, it is impossible to fit the factory wheel without a spacer. The only other option would be an aftermarket wheel with the correct offset included to create the necessary space to clear the caliper. The "offset" of the rotor known as the "hat height" was how I was able to locate the correct rotor in the first place. I knew the rotor needed to be 321mm (12.64") and the rotor height needed to be the same as the factory of 45.6mm., bolt circle pattern be damned! No other vehicle had the rotor combination of the correct diameter and height other than the Buick Cascada. The GM number was 13512340. If you can find another rotor with the correct 105mm bolt circle instead of the 115mm bolt circle the Cascada rotor comes with, or an alternate vehicle that utilizes this same rotor, please let the community know. I stopped looking after I found that one!

 

[NDarkling]

So the caliper bracket bolt is larger on the Sonic than the one used on the Cadillac?

Sent from my SM-G950U using Tapatalk

 

[CorradoKev]

So the caliper bracket bolt is larger on the Sonic than the one used on the Cadillac?

Sent from my SM-G950U using Tapatalk

No. On the original Sonic brake setup, there is a caliper and a caliper bracket. I originally upgraded from the O.E. brakes to the Encore brakes which required a larger caliper bracket bolt (12mm to 14mm) and drilling the holes in the spindle larger to accommodate the larger bolt. When using the Cadillac calipers, there is no bracket as the caliper includes the mounting holes and the 14mm bolts from the Encore setup fit perfectly. Not the best picture attached, but it shows that there’s no bracket on the Cadillac caliper.