Brake Pads on C8 Z51, Also Includes Pad Install on C7 GS & C7 Z51 the PDF Focus Is on the C8
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W A Technology Install “Low Dust” Brake Pads on C8 Z51, Also includes pad Install on C7 GS & C7 Z51 The PDF Focus is on the C8. Since it has similar double sided “brake tape” holding pistons to front pads as my early 2014 Z51, those details are included. Note, you’ll need low dust pads or like the ~6-month experience with my 2014 Z51 you’ll be cleaning brake dust from the wheels every few hundred miles. If I didn’t, the dust not only looked bad it was pitting my black wheels! Forum Posters state C8 Z51 brake dust is as bad as the C7 Z51, Grand Sport and Z06! Our 2017 Grand Sport install is also covered. It was simple since NO “Brake Tape” on the front pads! BUT since we started with PowerStop Z26 pads and tossed them at ~900 miles, it includes an Appendix with info and the research done to define the likely reason for their inferior performance with cold pads. ALTHOUGH I INSTALLED THE C8 PADS WITHOUT REMOVING THE CALIPERS (which is shown in the following detailed Pics/Captions,) for a straightforward install and without the risk of damage to piston “Dust Boots” .....: SUGGEST REMOVING THE CALIPERS BY SAFELY LIFTING HIGH ENOUGH! With ~20,000 2020 C8s sold and 54% Z51’s (that need low dust pads.) Have received feedback from “Strake,” a Forum Member that my thought of an easier breaking tape hold DID NOT WORK. I have provided info on what he used to remove his calipers. Consider these jacking steps UNLESS YOU HAVE A LIFT: 1. First, GM recommends disconnecting the battery to prevent the possible inadvertent activation of the ~3000 psi eBoost hydraulic pump. 2. To remove the front calipers (no tape, so not needed in the rear) the car must be lifted about 17 inches. Suggest using two jacks (I have 2 that can lift 20+ inches,) lifting a few inches alternately on each side. 3. However, DO NOT WORK ON THE CAR only supported by jacks. 4. Therefore, to use jack stands you must remove the front Aero Panels. To access those “panel bolts” the car must be lifted safely. I would place the front wheels on my ~7-inch-high stanchions for that task. 5. Then jack both sides equally to rase to ~18 inches and insert jack stands on accessible and safe frame members. 6. Then BEFORE removing the 155 ft-lb caliper bolts, remove the center caliper brace and pad support bolts (as I did for with the calipers in place.) 7. With the caliper removed it’s easy to break the “brake pad tape” hold. 8. Then reinstall the caliper to reduce the time you’ll need a “second pair of hands” to hold the caliper avoiding the need for brake bleeding! It’s also easier than trying to install the caliper with the new pads in place. Copyright by WA Technology, LLC [email protected] Page 1 Photo Install Sequence of Brake Pad Install First Decision for the C8: Do you remove the brake caliper? OR, as I did, the center caliper brace and then pads with the “Caliper in Place.” Pic right is from a video that showed what was done from a lift to remove the caliper first. It has some advantages and no “risk. However, the bolts have a 155 ft-lbs torque spec. There are two 20mm hex head bolts Considering the difficulty and risk of and require room for a breaker bar and nicking the Piston Dust Boots I would torque wrench. have removed the Calipers! A recent Forum Post by “George Vee” (who has a drive on lift) made me look carfully of how I would get my car high enough to remove the two 155 ft-lb Torque requiment bolts and retorque to that level. In addition, need another “pair of hands” to hold the caliper so the brake line does not have to be disconnected, then bleeding the bakes etc. Might be able to devise a method to hold the caliper but a “pair of extra hands” would be easiest! George Vee provided this information sheet from the service manual. Note the bolts are about in the center half of the caliper. Can also see the lower caliper bolt being removed in the top pic on this page. Suspect it will require more than the 155-ft-lb tightening torque to loosen. My ½ inch drive breaker bar and a 6-point 20 mm socket would work. Same with my 21 inch long 150 ft-lb torque wrench when reinstalling. Copyright by WA Technology, LLC [email protected] Page 2 I do have two high lift jacks. My long reach jack has a max lift of 23 ½ inches. The bottom caliper bolt is about 11 inches from the ground. Using my 2 inch high Jack Pads and the high lift jack will put that bottom bolt over 30 inches off the ground. More than enough room for my breaker bar and 21 inch long Torque Wrench. Would jack both sides evenly in increments and continually check that the jacks move in and the jack saddle stays under the Jack Pads! To be safe, need to support the car with Jack stands NOT just jacks before working underneath. That requires removing the aero panels to access suitable frame supports. GM Pic right. BUT to remove the aero panels need to be safe as well, so first, would put the front wheels on stanchions while the aero panel bolts are removed. Then loosen the wheels and raise the jacks so the lower caliper bolt was about 18 inches above the floor. That will require lifting the car 17 inches with the jacks. To safely remove the bolts holding the front aero panels must have it supported before going under the car. As was done when I installed my C7 Carbon Splitter, (Pic left) would raise the car and support with the wheels on my wood stanchions. Made two ~10 years ago from a 12 foot long 2X6 and ¾ inch playwood. Details of the simple construction with calculations showng “Safety Factors” (I made for fun when some folks questioned the safety) are in my “Jacking a C8 and C7 Corvette PDF.” A link to it and ~50 others is after this Brake Pad Install PDF! Copyright by WA Technology, LLC [email protected] Page 3 Why the “remove caliper” approach may be easier and safer. The double sided “brake tape” used to hold the pads to the caliper pistons is strong in tension and shear BUT not in “Peel” or what is called “Cleavage.” Need room to use this separation mechanism. Not much room with rotor and pads in place! First, I would remove the center caliper brace and spring,- easy to do. Once caliper is off the car (hydraulic hose still connected) put a screwdriver between a pad and caliper and pry. It will “Peel” away from the tape in “Cleavage” as without rotor there is pleantly of room. Once reinstalled, insert new pads, put in pad holding screws, bolt caliper center brace and spring. Note, Strake stated putting the caliper back with new pads in place was not easy. I saw that in an early video which is why I recommend removing the caliper brace bolt and installing the caliper without pads and add those after it is bolted back in the car. NOTE: MY THOUGHT OF A POSSIBLE WAY TO DEAL WITH BRAKE TAPE _ DID NOT WORK. Forum Member, “Strake” reported Trying my thought to get the pads lose safely from the tape holding them to the pistons. IT DID NOT WORK SO HE REMOVED HIS CALIPERS! The thought was to use Vice Grips and twist a screwdriver placed between the pistons. As he reported, just not enough room to have the tape peel away from the pistons with the rotor in place! Copyright by WA Technology, LLC [email protected] Page 4 Strake used two of these Rennstand sold by Safe Jack combo jack pad and jack stand. He bought two and jacked both sides at the same time (which I would do as well.) You jack the car with the top section then add the sides while the jack is in place. Rennstand says there 18M-R33 model can lift to over 16 inches, which will be more than enough to remove the caliper bolts. It sells for $125/each but you will need the jack pad that fits the C8 oval slot, which is extra. Strake only had a pic of his rear lifted but you can see that after jacking you insert the RENNSTAND legs and can remove the jack. So, you are jacking and using a jack stand in the same location. It is simpler than my suggestion of using a two-step process and removing the aero panels to gain access to the center frame members to use jack stands. However, it does cost $250 plus the C8 jack pad costs. There is a similar product to RENNSTAND called JackPoint that operates in a simiar way. You jack up the car then insert the “JackPoint” base. BUT it’s a fixed height limited to about 12 inch lift and cost $325 each. Note they both, JackPoint and RENNSTAND, require the proper jack pad that fits their device AND the C8 oval slot. Copyright by WA Technology, LLC [email protected] Page 5 Install With Caliper In Place The C8 Z51 has 4 piston calipers, front and rear. The front caliper-brace bolt has to be removed to remove the pads.