do not press the back button…
Your Vehicle
Porsche // Cayenne 9YA (E3) 2018-2023 // 9YA Cayenne Coupe S V6 2.9L Petrol (440Hp) 2019-23
Enter your VAT number here and click Verify:
Your details have been verified. VAT number registered to:
,
.
Your order will now be zero rated for VAT purposes. We reserve the right to verify these details after your order request has been made and reinstate VAT if required.
Your VAT details were not recognised or were invalid. Your VAT number must be matched to your Billing Country as specified above. This is currently specified as . You do not need to enter the country code part of your VAT number as this has already been selected in your billing address details above.
The VAT number checking service is currently offline. Please supply your VAT details within the comments or special instructions field below and we will apply a VAT discount after placing your order request.
- Porsche 911 1984-1986 3.2L
- Porsche 911 1987-1989 3.2L G50
This OE Match-standard brake caliper seal repair kit is engineered as a direct-fit replacement for the rear brake caliper sealing components on classic Porsche 911 models. This kit supplies the essential gaskets, seals and dust boots needed to rebuild the brake caliper’s sealing surfaces accurately.
Sold per caliper.
Porsche 911 1984-89 (Rear)
This kit is sold on a per-caliper basis - for reconstructing or refreshing one rear brake caliper’s internal seals and dust protection.
In a brake caliper, seals and dust boots play a critical role in maintaining hydraulic integrity and protecting internal components from dirt and moisture. Over time seals can harden, crack or shrink, leading to fluid leaks, reduced braking performance, and uneven pad wear. This kit provides the correct rubber components to refresh the caliper sealing surfaces, allowing pistons to move freely while maintaining fluid pressure and protecting against contamination.
Function
• Hydraulic Seal Function: Prevents brake fluid leakage from the caliper piston bore under pressure.
• Dust Protection: Dust covers keep contaminants out of the caliper internals, reducing corrosion and wear.
• Restore Performance: Helps return caliper piston travel and braking response to as-designed levels.
• Durability: rubber materials resist heat, fluid exposure and aging typical of high-stress brake system environments.
Brake caliper seals and dust boots wear with age and use. When the seals degrade, brake fluid can leak at the caliper piston, reducing hydraulic pressure, degrading braking performance, and potentially causing uneven pad wear or pulling under braking. Dust boots that are cracked or missing allow grit and moisture into the caliper bore, accelerating corrosion and piston binding. Replacing these with an OE Match kit helps restore correct brake function, maintain consistent pedal feel, and extend the life of your brake calipers.
Replace the brake caliper seal kit if you notice:
• Brake fluid leaks around the caliper piston seal.
• Spongy or inconsistent brake pedal feel.
• Uneven pad wear or reduced braking performance.
• Cracked, hardened or missing dust covers.
• During a full brake overhaul or rebuild.
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
91135290500
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
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
00004330511
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
The product you are viewing cross references to these numbers