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- Porsche 911 1974-1977 2.7L / 1976-77 3.0 Carrera
- Porsche 911 1978-1983 3.0L / SC
OE Match rear brake caliper seal repair kit designed to service the rear brake calipers on classic Porsche 911 (1974–1983) models. Now you can restore your brake calipers performance with our Rebuild Kits. Each kits includes the necessary seals and dust covers that you will need for the rebuild process.
Sold per caliper.
Porsche 911 1974 - 1983
The brake caliper seal kit replaces the internal piston seals, dust boots, and associated rubber components within the rear brake caliper. These seals perform essential functions:
• Maintain brake fluid integrity inside the caliper piston bore
• Prevent fluid leakage under hydraulic pressure
• Protect internal components from dirt, moisture, and debris
• Enable smooth piston movement for consistent brake pad engagement
• Help ensure even pad wear and reliable stopping performance.
Over time, original caliper seals harden, crack, or lose elasticity, which can lead to leaking, sticking pistons, uneven braking, and reduced safety.
Function
• Hydraulic sealing: Ensures brake fluid stays within the caliper bore
• Piston movement control: Allows smooth, controlled piston travel
• Dust and dirt exclusion: Prevents contaminants from entering the caliper bore
• Brake performance preservation: Helps maintain even pad engagement and return.
A properly rebuilt caliper with new seals helps restore brake responsiveness and reduces the risk of brake drag or uneven braking at the rear wheels.
Brake caliper seals are critical for hydraulic braking performance and safety. Old seals often suffer from: • Hardening and cracking due to heat and age • Swelling or deformation from fluid contamination • Loss of elasticity, causing piston bind or leak paths • Corrosion of caliper bores when moisture enters through failed dust boots Worn or leaking seals result in reduced brake performance, fluid leakage, uneven pad wear, brake drag, and compromised stopping power. Replacing them with an OE Match seal kit restores proper fluid retention and piston mobility - increasing safety, consistency, and brake system longevity. When to replace. Install this rear brake caliper seal kit when: • Calipers are leaking fluid around the piston area • Brake pistons stick or bind, causing brake drag • You are performing a full caliper overhaul • Pads and rotors are replaced and calipers are difficult to service • Dust boots are torn, brittle, or missing. A seal kit is a core part of brake caliper rebuilds and should be considered whenever the caliper is disassembled.
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
91135299800
The product you are viewing cross references to these numbers
Price is each seal
**Please check the piston size you need as some callipers take two different sizes.
Fits:
Various Models
Price is each seal
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
1055955
The product you are viewing cross references to these numbers
Brake Caliper Replacement Pistons for Brembo Calipers
Sold each
Restore the performance and reliability of your Porsche Brembo braking system with these OE Match Brake Caliper Replacement Pistons. Manufactured to original equipment specifications, these precision-engineered pistons are designed for rebuilding Brembo brake calipers fitted to a wide range of Porsche models.
Available in 28mm, 30mm, 32mm, 34mm, 36mm, 38mm, 40mm and 44mm outer diameters, every piston has an overall height of 32mm and is manufactured to deliver the correct fit, smooth operation and dependable sealing performance when used with new piston seals and dust boots.
Important: Please check the piston diameter required for your specific caliper before ordering. Many Brembo calipers use two different piston diameters within the same caliper to optimise braking performance. The sizes listed refer to the outer diameter (OD) of the piston.
What Does a Brake Caliper Piston Do?
The brake caliper piston is one of the most important components inside the braking system. Hydraulic brake fluid pressure pushes the piston forward, forcing the brake pad firmly against the brake disc to generate the friction required to slow or stop the vehicle.
Its primary functions include:
- Converting hydraulic pressure into braking force.
- Applying even pressure across the brake pads.
- Ensuring smooth and consistent piston movement.
- Maintaining balanced braking performance.
- Supporting Porsche ABS and stability control systems.
- Delivering precise pedal feel and braking response.
Correctly functioning pistons are essential for maintaining the powerful, progressive braking performance expected from Porsche Brembo calipers.
Why Do Brake Caliper Pistons Fail?
Brake caliper pistons operate in harsh conditions and are continually exposed to heat, moisture and brake dust. Over time they can become damaged or worn.
Common causes include:
- Corrosion caused by moisture ingress.
- Torn or damaged dust boots.
- Contaminated brake fluid.
- Surface pitting.
- Heat generated during heavy braking.
- Seized pistons caused by corrosion.
- Damage during previous repairs.
- High mileage and normal wear.
A damaged piston can prevent the caliper from operating correctly, leading to reduced braking performance and uneven brake pad wear.
Symptoms of a Worn or Damaged Caliper Piston
Common symptoms include:
- Sticking or seized brake calipers.
- Uneven brake pad wear.
- Vehicle pulling during braking.
- Reduced braking performance.
- Overheating brakes. Brake drag.
- Fluid leaks around the piston seal.
- Difficulty retracting the piston during servicing.
Replacing damaged pistons during a caliper overhaul restores smooth operation and reliable braking performance.
When Should Brake Caliper Pistons Be Replaced?
Replacement is recommended whenever:
- Corrosion or pitting is visible.
- Pistons become seized or difficult to move.
- The caliper is being rebuilt.
- Dust boots have failed allowing contamination.
- Brake fluid leaks occur around the piston.
- Uneven pad wear is caused by sticking pistons.
- Restoring older Brembo brake calipers.
- During preventative maintenance on ageing braking systems.
For the best results, new pistons should always be installed with new piston seals and dust protection boots.
OE Match Quality You Can Trust
These OE Match Brake Caliper Replacement Pistons offer:
- Manufactured to original equipment specifications.
- Precision-machined finish.
- Excellent corrosion resistance.
- Smooth piston movement.
- Direct replacement fitment.
- Suitable for Brembo brake calipers.
- Available in 28mm, 30mm, 32mm, 34mm, 36mm, 38mm, 40mm and 44mm diameters.
- Uniform piston height of 32mm.
- Ideal for professional caliper rebuilding.
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
1055955
The product you are viewing cross references to these numbers
DOT 4
Having an extremely high boiling point and lower viscosity than required, it meets and greatly exceeds regulatory standards. Also suitable for vehicles with ABS.
Vapour Lock formation
This sort of habit leaves room for the Vapour Lock, the formation of vapour bubbles due to boiling of the brake fluid that replace the normal fluid and are compressed, thereby sending the brake pedal to its fill stoke (spongy pedal). The origin is incident in the porosity of the tubes that make up the braking circuit, which in time draw moisture into the fluid, drastically reducing the boiling point. The result is a reduced braking efficiency.
Brembo Premium Brake Fluid
Brembo Premium brake fluids have a higher boiling point that exceeds the standard, thus offering superior resistance to the Vapour Lock and ensuring braking efficiency even at low temperatures. With high anti-corrosion properties and resistance to oxidation, Brembo brake fluid also allows for long-term unaltered chemical/physical characteristics of the fluid in operating circuit; therefore, preserving its integrity.
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
L040
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