Over time your Brembo calipers may get cracks in the piston dust boots. When this happens, dust/dirt can get into the caliper pistons and cause them to not engage properly. Sticking caliper pistons can exhibit one or more of the following symptoms:
This guide will review how to change the dust boots without removing the brake calipers. The guide is specific to the four-piston Brembo calipers that are on the older SRT Challengers and Challenger Scat Packs without the optional six-piston Brembos. However, I can't imagine the process will be much different for the six-piston Brembo calipers.
How to change the caliper dust boots without removing the caliper
Important Note: Centric/StopTech dust boots which are advertised as high temperature are not good quality. My original Brembo dust boots lasted over 5 years and 8 weekend track events before they started cracking. I installed the Centric/StopTech boots and they have already started cracking after two events. The one thing I noticed when I first installed the Centric/StopTech boots is that they were extremely thin. I would recommend purchasing authentic Brembo replacements if you perform this procedure.
Caliper Boot Sizes
Standard Four Piston Brembo Calipers
Front - 44mm
Rear - (qty 2) 28mm (qty 2) 32mm
Six Piston Brembo Calipers
Front - 36mm
Rear - (Unsure, if someone can help me here I will update this later)
Sources
Zeckhausen Racing - While Zechhausen sells extremely overpriced replacement dust boots by Stoptech/Centric, they are not good quality. They are extremely thin and didnt hold up well for me and a few other challenger/charger users in other forums. However, they do sell other replacement parts.
Hoerr Racing Products HRP **RECOMMENDED - I ran across this gem of a company the other day. They sell authentic Brembo dust boots which are far better quality than Stoptech/Centric and at a great value. I placed an order over the weekend for dust boots along with some racing gear and they promptly called me this morning to tell me they were out of one of the other products that I purchased and asked if I would like them to order it with a delay or to remove it from the purchase. I am very impressed with their prices and service.
- Car pulling to one side
- Uneven brake pad wear
- Increased brake pad wear
- Excessive rotor and caliper heat
- Reduced braking effectiveness
This guide will review how to change the dust boots without removing the brake calipers. The guide is specific to the four-piston Brembo calipers that are on the older SRT Challengers and Challenger Scat Packs without the optional six-piston Brembos. However, I can't imagine the process will be much different for the six-piston Brembo calipers.
How to change the caliper dust boots without removing the caliper
- Remove your brake pads, unbolt your caliper and use a bungee cord to hang it off of your spring (to prevent it from hanging by the brake line).
- Clean the inside of your caliper. I use brake cleaner and blue shop towels. If buildup is really bad, use a small brush.
- Pump your brakes in small increments until the pistons start to come out. The pistons may come out unevenly. This is normal and doesn't always mean that you need to rebuild your calipers. You want to target getting all of your pistons to come out but not too far. Please be aware that if you pump the brakes too much that the pistons can come out. If you are nervous about them coming out too far, put a piece of wood inside the caliper to prevent it from happening. However, if you take it slow, they will not come out too far.
- Closely examine your caliper boots. Do they show any wear? Are there any small cracks starting to form? This image is from my rear calipers on my 2015 Scat Pack with 45k miles and 8 track events.
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- Use a small flathead screwdriver and press it between the boot and the caliper on each side. The caliper dust boot should pop off fairly easily. The front calipers have a small notch on the dust boot that you can use to place your screwdriver.
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- Once you remove the caliper dust boot, use a clean rag and wipe around the piston. You can also use a large flathead to pry out the piston slightly further and to wipe around the outside of the piston (where the highest chance of dirt buildup is).
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- Slide the new caliper dust boot onto the piston. Twist it in a circle to ensure it is completely locked into the groove and not folded over.
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- Press the piston back down and then press the caliper dust boot into the caliper. Be careful not to tear the boot if you use a tool to press them. The rear calipers I was able to press in by hand. The front calipers I used a piece of wood. You want to ensure that you press the piston down first so that you don't trap a bunch of air between the dust boot and piston.
- Repeat for the remaining dust boots. Please note, you should always perform brake work in pairs. Meaning if you have a cracked boot on the left rear, you should go ahead and change out the dust boots on both rear calipers.
Important Note: Centric/StopTech dust boots which are advertised as high temperature are not good quality. My original Brembo dust boots lasted over 5 years and 8 weekend track events before they started cracking. I installed the Centric/StopTech boots and they have already started cracking after two events. The one thing I noticed when I first installed the Centric/StopTech boots is that they were extremely thin. I would recommend purchasing authentic Brembo replacements if you perform this procedure.
Caliper Boot Sizes
Standard Four Piston Brembo Calipers
Front - 44mm
Rear - (qty 2) 28mm (qty 2) 32mm
Six Piston Brembo Calipers
Front - 36mm
Rear - (Unsure, if someone can help me here I will update this later)
| Piston Size | Brembo Dust Boot Part Number |
| 28mm | 20.4872.40 |
| 32mm | 20.4872.42 |
| 36mm (6 piston models) | 20.4872.44 |
Sources
Zeckhausen Racing - While Zechhausen sells extremely overpriced replacement dust boots by Stoptech/Centric, they are not good quality. They are extremely thin and didnt hold up well for me and a few other challenger/charger users in other forums. However, they do sell other replacement parts.
Hoerr Racing Products HRP **RECOMMENDED - I ran across this gem of a company the other day. They sell authentic Brembo dust boots which are far better quality than Stoptech/Centric and at a great value. I placed an order over the weekend for dust boots along with some racing gear and they promptly called me this morning to tell me they were out of one of the other products that I purchased and asked if I would like them to order it with a delay or to remove it from the purchase. I am very impressed with their prices and service.
