[Ren Lacerda]

Hello everyone! I'm a novice on self-maintenance, having a blast learning to keep my 2017 2SS ready for track days and HPDE.

I'm stuck on installing GM's track brakes cooling kit, more specifically with removing the 4 piston Brembo front calipers' bolts:

1. What are the right size bolts? 19mm and 3/4 are little lose, 17 and 11/16 won't fit. Are these 18mm or 23/32?

2. The bottom caliper bolt is in a tricky angle, even with the sterering wheel all turned in to the right. Are swivel sockets an appropriate solution here? Can I use my impact wrench + swivel sockets to lose these two piston bolts?

3. Can I reuse these piston bolts every time I install/remove the track brake cooling kit before/after track time, as long I'm using the correct spec threadlocker?

Thanks in advance!

[2SS Capt]

Originally Posted by Ren Lacerda

Hello everyone! I'm a novice on self-maintenance, having a blast learning to keep my 2017 2SS ready for track days and HPDE.

I'm stuck on installing GM's track brakes cooling kit, more specifically with removing the 4 piston Brembo front calipers' bolts:

1. What are the right size bolts? 19mm and 3/4 are little lose, 17 and 11/16 won't fit. Are these 18mm or 23/32?

2. The bottom caliper bolt is in a tricky angle, even with the sterering wheel all turned in to the right. Are swivel sockets an appropriate solution here? Can I use my impact wrench + swivel sockets to lose these two piston bolts?

3. Can I reuse these piston bolts every time I install/remove the track brake cooling kit before/after track time, as long I'm using the correct spec threadlocker?

Thanks in advance!

18mm

If you turn the wheel all the way you can get an 18mm deep socket and a standard impact wrench on both bolts.

Yes, you can reuse the bolts, proper torque 148 ft/lb.

Thread locker is Loctite 272

[terry_b]

I know it's been debated on here before but those are torque to yield bolts... Which means that they stretch when they're properly installed and I replaced mine when I did my rotors for peace of mind. Plenty of people have reused those bolts though and I've never heard of any failures... So really I guess it's a personal choice.

Sent from my Pixel 4 XL using Tapatalk

[2SS Capt]

Originally Posted by terry_b

I know it's been debated on here before but those are torque to yield bolts... Which means that they stretch when they're properly installed and I replaced mine when I did my rotors for peace of mind. Plenty of people have reused those bolts though and I've never heard of any failures... So really I guess it's a personal choice.

Sent from my Pixel 4 XL using Tapatalk

The GM document for the Track Deflector and Splash Shield installation (GM Part #23385148) doesn't say anything about not reusing the caliper bolts. (There is no mention on replacing the bolts, just reinstalling with Loctite).

[Ren Lacerda]

Originally Posted by 2SS Capt

18mm

If you turn the wheel all the way you can get an 18mm deep socket and a standard impact wrench on both bolts.

Yes, you can reuse the bolts, proper torque 148 ft/lb.

Thread locker is Loctite 272

Thanks 2SS Capt, 18mm ball swivel socket + 18in breakbar did the trick!

About the torque, service manual says 111 lb ft first pass and 15-30 degrees 2nd pass. What does that 1st and second pass means?

https://imgur.com/a/Or4ZHHC

EDIT: Nevermind, found out what torque+angle means. Gotta use a tool like this for the second final pass:

https://www.autozone.com/test-scan-a...uge/141510_0_0

[2SS Capt]

Originally Posted by Ren Lacerda

Thanks 2SS Capt, 18mm ball swivel socket + 18in breakbar did the trick!

About the torque, service manual says 111 lb ft first pass and 15-30 degrees 2nd pass. What does that 1st and second pass means?

https://imgur.com/a/Or4ZHHC

Interesting as the Track Deflector and Splash Guard instructions say 148 lb/ft...

I would say first pass, tighten both to 111 lb/ft and then go back to each and tighten an additional 15°-30° of turn (I'm guessing that will put you somewhere near 148 lb/ft of torque )...

[Ren Lacerda]

Originally Posted by 2SS Capt

Interesting as the Track Deflector and Splash Guard instructions say 148 lb/ft...

I would say first pass, tighten both to 111 lb/ft and then go back to each and tighten an additional 15°-30° of turn (I'm guessing that will put you somewhere near 148 lb/ft of torque )...

I "calculated" the same, 111+15-30 degrees=148 lb ft

[Stephen12ZL1]

all of the fasteners are metric even though there are standard equivalents of some sizes

[JCunningham]

Originally Posted by 2SS Capt

18mm

If you turn the wheel all the way you can get an 18mm deep socket and a standard impact wrench on both bolts.

Yes, you can reuse the bolts, proper torque 148 ft/lb.

Thread locker is Loctite 272

this is correct.
there are no torque to yield bolts except maybe the head bolts. iv measured then all with a micrometer. none stretched and GM even states now you can reuse the caliper bolts.

[Ren Lacerda]

Originally Posted by JCunningham

this is correct.
there are no torque to yield bolts except maybe the head bolts. iv measured then all with a micrometer. none stretched and GM even states now you can reuse the caliper bolts.

Awesome confirmation! Thanks JCunningham.

[TheRealJA105]

Originally Posted by Ren Lacerda

3. Can I reuse these piston bolts every time I install/remove the track brake cooling kit before/after track time, as long I'm using the correct spec threadlocker?

Thanks in advance!

Just leave the kit on, plenty of us do with no issues and it's really not worth the hassle of removing every time. If you are against that I would still say only remove the actual air deflector on the control arms and not worry about removing the calipers to put the rotor shield back on.

[Efi69Cam]

A torque angle spec does not mean it’s a torque to yield bolt. The yield point could affect the reading on a torque wrench so all tty bolts are installed with torque angle specs.

Torque angle is more reliable as it takes the friction out of the equation when tightening the bolt to the stretch the engineers intended. On these brake bolts simply using a liquid thread locking compound instead of the dry the new bolts come with would change the torque reading. Torquing to 148 lbs would result in more stretch on the bolt with the liquid.