How to Mask Brake Calipers & Brackets for Powder Coating

By Lee Lechner
Dec 23, 2025

Brake calipers and brackets require precision masking to protect critical surfaces during powder coating and painting processes. This guide covers the key areas that need protection and the masking solutions that work best.

Note: This guide primarily focuses on masking designs used in mid- to large-scale coating operations to optimize masking installation/removal times. If you’re looking to mask only a few calipers or brackets, we recommend using green poly masking tape (or glass cloth tape for thicker coats) to avoid long lead times and tooling costs associated with custom die-cuts and molded masking.

What Needs to Be Masked and How

When masking brake calipers and brackets, you're protecting surfaces that are essential for proper brake function and safety. The primary areas that require masking are the brake caliper bores, the banjo bolt port, bleeder ports, mounting ears/surfaces, and the caliper brackets. Below is an overview of each area as well as a list of masking solutions specific to each one:

Masking Brake Caliper Bores

The piston bore is the cylindrical cavity inside the caliper body where the piston moves. This area must remain completely free of coating to maintain sealing integrity, smooth piston movement, and for a number of other safety reasons.

Masking Solutions: When it comes to masking this area of a brake caliper, coaters typically use:

Green poly tape / die-cuts: We only recommend this option for lower volume jobs, but green poly tape is a great option due to its high-temperature resistance and ability to leave a clean line with no residue
Screw-Together Masks: This is typically 2 silicone plugs that fasten together via a bolt. We don’t typically recommend this option because coaters have run into issues with over-tightening, resulting in masking-related issues
Masking Bore Sleeves: This is a better alternative to screw together masks, but the issue you may run into is that these can be difficult to install, depending on the length of the sleeve needed
Custom Molded Masks with Nylon Brace: To ensure a tight, consistent seal, these masks are paired with a nylon 66 support bracket (not shown), which distributes pressure across the molded mask for a tighter seal.

Masking Banjo Bolt Port (Brake Hose Inlet Port)

This is the machined hole where the banjo bolt and crush washers secure the brake hose fitting to the caliper body. Because the banjo bolt seals against the caliper using copper or aluminum crush washers, any coating on these flat sealing surfaces causes improper sealing and can lead to brake fluid leaks. Coatings inside the threaded hole can alter thread tolerances. This can lead to issues in applying proper torque and can damage threads - the excess coating could even flake off and contaminate brake fluid.

Masking solutions: Powder coaters will typically use either custom green poly die-cuts or custom molded masks sized specifically for the banjo bolt port opening (shown in the image).

Masking Bleeder Ports

The bleeder port is a small threaded hole where the bleeder screw threads in. It includes two critical areas: the threaded bore and an internal conical seat that the bleeder screw tip seals against.

Masking is essential here because even a thin film of coating ruins the seal, causing brake fluid leaks or air intrusion. Coating inside threads can bind the screw, give false torque readings, or flake off during tightening.

Masking solution: Use silicone push plugs or, better yet, custom precision tapered plugs designed specifically for bleeder valve threads, like the one shown in the image. This plug is designed to lock into the threaded port and has a pull handle for easier installation and removal.

Masking Mounting Ears and Mounting Surfaces

Mounting ears are the protruding tabs with bolt holes or guide pin holes used to mount the caliper to the vehicle's knuckle or bracket. Mating surfaces need to remain paint-free to ensure proper alignment and even torque distribution.

Masking solution: Use silicone push plugs for bolt holes and die-cut shapes or high-temp tape for flat mating surfaces.

Green Poly Die-Cuts
Custom Molded Washer Plugs (Shown in image)
Custom Molded Plugs integrated with the racking system
Magnetic Masking Cover

Masking mounting surfaces on brake bracket

Masking Brackets

These are the flat machined areas on the caliper bracket where it contacts the caliper body. These surfaces control caliper alignment and pad positioning.

Masking solution: Apply die-cut masking shapes or go with custom silicone covers to mask surfaces that need to remain free of coating. These will sometimes require a metal or nylon brace as well.

Best Masking Tapes for Masking Brake Calipers and Brackets

Based on the temperature requirements of powder coating (typically up to 400°F/204°C) and the need for precision sealing, alongside thicker coatings, the two most common tapes we recommend are:

Green Poly Masking Tape: Industry standard masking tape option for clean lines, without residue when powder coating
Glass Cloth Masking Tape: Recommended for you’re applying thicker coats

green poly masking tape for brake calipers — Green Poly Masking Tape (Most Common)

Glass cloth masking tape for brake calipers — Glass Cloth Masking Tape for Thicker Coats

Common Masking Design Challenges

With all that said, brake calipers are not the easiest of components to mask. They present unique masking challenges, like inconsistencies in construction and complex caliper designs:

Cast construction inconsistencies: Since calipers are cast, each part has slight variations, making it difficult to achieve consistent seals with rigid masking.
Bridging problems: Thick powder coating can bridge across masking edges. Many designs include skirts or extended coverage to prevent this.
Complex geometries: The irregular shapes and internal passages make achieving solid seals challenging, which is why many of the masks developed for calipers and brackets include a high-temp glass-filled nylon brace. Or, so coaters will fabricate their own brace that masking will be designed around.

Best Practices

Always clean surfaces before applying masking to ensure proper adhesion
Verify that all critical sealing surfaces are completely covered before coating
Use color-coded masking components to streamline production and reduce errors
Consider reusable silicone masking solutions for high-volume operations to reduce costs and labor time
Inspect masking after coating to ensure no coating penetration occurred

Leverage a Trusted Masking Partner

Proper masking of brake calipers and brackets is essential for both safety and functionality. By protecting precision-machined sealing surfaces, threaded bores, and mating surfaces, you ensure that coated brake components perform reliably and safely. Working with an experienced masking supplier who understands brake system requirements can help you select the right masking solutions for your specific caliper designs and production volume.