Installation Instructions: Brake Caliper Adapter for MINI Cooper R56 JCW & R53 S – Conversion to Renault Megane 3 RS 4-Piston Brake Calipers with MINI GP2 330x26-mm Brake Discs Product 1321

Important  

Please read these instructions carefully before starting the work. If the conversion is too difficult for you, please hire a professional to do the installation. We cannot provide a warranty for consequential damages due to improper installation. Correct installation and adjustment save time, costs, and trouble.  

Dismantling: 

•  Old brake system (brake disc, brake caliper, and caliper bracket) 
•  Remove or modify air deflectors or brake dust shields or anchor plates (we prefer removal to ensure better brake ventilation).

!!Important!!:  

What do you need for this?  

• Depending on technical knowledge, about 1-2 hours of time  
• Torque wrench with suitable attachments  
• Liquid threadlock  

1. Introduction & Benefits of the Brake Conversion

With the Epytec brake caliper adapter item 1321, you can convert the front axle of your MINI Cooper R56 JCW or a compatible MINI Cooper S R53 to a high-performance braking system with 4-piston brake calipers from the Renault Megane III RS and the 330x26 mm brake discs from the MINI GP2.

Directly access the suitable Epytec brake caliper adapter item 1321 here.

The optimal solution lies in using proven components from production vehicles for the conversion. The Renault Megane III RS 4-piston brake calipers are used in conjunction with the 330x26 mm MINI GP2 brake disc. Compared to a smaller production brake system, this offers more thermal reserve. This is a significant advantage, especially during repeated heavy braking.

The cost efficiency is also interesting. Brake discs, calipers, and pads are based on mass production parts and can be individually replaced later when worn. So, you are not permanently dependent on specially manufactured wear parts.

Another advantage is the reversibility. The Epytec adapter is mounted on the existing mounting points. According to the product description, no permanent modifications are necessary on the wheel bearing housing or steering knuckle. If the vehicle is later returned to the original brake system, the adapter and conversion components can be removed again.

The Epytec adapter has a hole spacing of 120 mm on the steering knuckle side and 130 mm on the caliper side. Installation is done on the front axle.

2. Important Check Before Assembly

Before you completely disassemble the existing brake system, you should check that all parts are present and undamaged. Especially used Megane-RS brake calipers must be checked for damaged threads, leaking piston seals, stiff pistons, damaged bleed valves, and corrosion.

Very important: Also check the wheel clearance. A larger fixed caliper requires significantly more space behind the wheel spoke. Thus, the wheel size itself does not necessarily indicate if the wheel will actually fit. The interior contour, offset, and shape of the wheel spoke are decisive.

Therefore, first try to assemble the new brake system provisionally and then mount a wheel. The brake caliper must not touch the wheel at any point. No contact should occur even when the wheel is rotated.

3. Step-by-step Guide

Step 1: Prepare and Safely Lift the Vehicle

Park the MINI on a solid and level surface. Loosen the wheel bolts of the front axle only slightly at first. Then lift the vehicle with a suitable lift or at the designated lifting points and secure it properly.

Never work under a vehicle that is only supported by a jack!

Then remove both front wheels. Now you have free access to the existing brake system.

Step 2: Dismantle the Original Brake System

Dismantle the existing brake caliper according to the vehicle configuration. The brake line should only be opened when you are immediately continuing with the conversion of the line or the new caliper. This avoids unnecessarily long fluid discharge.

Never hang a detached caliper from the brake line. Attach it with a sturdy hook or wire to the strut as long as the line is still connected.

Then remove the existing brake disc. If the disc is stuck to the wheel hub due to corrosion, work evenly and carefully. Do not transfer force to wheel bearings or sensitive suspension parts.

Step 4: Mount MINI-GP2 Brake Disc

Now place the 330x26 mm MINI-GP2 brake disc with BMW OE number 34116858071 onto the cleaned wheel hub.

Ensure that the disc rests fully and without tilting on the hub. Then clean the friction surfaces of new brake discs with brake cleaner if the disc manufacturer provides for the existing coating.

A practical tip: Secure the brake disc during further assembly with the intended fastening screw or suitable wheel mounting aids. This way, it won't move unnecessarily when attaching the adapter and brake caliper.

Step 5: Mount Epytec Brake Caliper Adapter

Apply the Epytec adapter neatly onto the prepared bolting surfaces on the wheel bearing housing. The adapter must rest completely flat. If it can't be applied cleanly, do not forcibly draw it to the mount with the screws. In this case, check again for rust, paint, a burr, or dirt between the contact surfaces.

Insert the supplied high-strength M12 fixing screws according to the Epytec specification. Where provided for the supplied screw material, secure the threads with medium-strength thread locker.

The M12 adapter screw connection is tightened to 150 Nm as per the installation instructions.

Initially work both fastening points hand-tight and then tighten in a controlled manner to the final torque. This prevents the adapter from becoming distorted during tightening.

Step 7: Prepare Brake Pads

Before inserting the brake pads, check and clean all contact and guide points.

A very thin layer of suitable ceramic paste can be applied exclusively to the designated metallic contact surfaces of the brake pads according to the installation instructions.

Do not apply paste to the friction surface of the brake pads or the brake disc! Even small amounts of lubricant on the friction surfaces can significantly reduce braking performance.

Step 9: Completely Bleed the Brake System

After completing the mechanical assembly, the brake system must be completely bled.

Use only the brake fluid approved for the vehicle. During bleeding, the reservoir must always remain sufficiently filled. If it is pumped empty, air can re-enter the system and the entire bleeding process must be repeated.

For a fixed caliper, it is also crucial that the bleeding points are actually located at the top. Air rises to the top in the brake caliper. If a bleeding point is not structurally at the highest point, air can remain in the brake caliper.

Continue bleeding the system until bubble-free brake fluid emerges and a clearly defined, stable pedal pressure is present.

If the pedal feels spongy, the vehicle must not be driven!

Step 10: Perform Leak Test

After bleeding, carefully clean all opened hydraulic connections. Then depress the brake pedal several times and hold it with strong pressure for a while.

Pay particular attention to the M10 hollow bolts, bleed valves, and line connections for any leaking brake fluid.

Even minimal moisture at a connection is a reason to check the cause. A brake system must be absolutely tight.

Step 11: Check the Freedom of Movement of the Complete Brake System

Turn the brake disc or wheel hub by hand. A slight grinding sound from new pads can occur due to design, but mechanical blockage or a hard contact should not.

Then check adapters, brake caliper, brake disc, and brake line with the steering wheel fully turned to the left and right.

Afterward, test-fit the wheel and check the clearance between the brake caliper and wheel spoke as well as to the wheel bed.

4. Common Sources of Errors & Troubleshooting

If a pulsating brake pedal or vibrations occur after installation while braking, you should first check the surface between the wheel hub and the brake disc. Rust residues or dirt can cause the brake disc to not lay flat.

If the brake caliper is visibly not centered over the brake disc, first check whether the Epytec adapter is completely seated and without any foreign objects on its surface. Also, check if the correct brake calipers and the correct 330x26 mm GP2 brake discs have been installed.

If the brake pedal is soft or spongy after bleeding, there is a high probability that air is still in the hydraulic system. Pay special attention to the location of the bleeding points and repeat the bleeding process properly.

If brake fluid leaks at the banjo bolt, do not move the vehicle. Check the correct arrangement and condition of the sealing rings, the sealing surfaces, and the thread. According to the installation instructions, the M10 banjo bolt is tightened with 18 Nm.

If the rim rubs against the brake caliper, the vehicle must not be driven in this condition. Check the rim geometry and offset. An appropriate and technically permissible wheel spacer can create additional clearance depending on the rim/vehicle combination but must in turn be properly tested and approved if necessary.

If a brake line rubs, its routing needs to be corrected. A line must never be fastened in such a way that it is tensioned during steering or compression.

4.5 Click here for the matching product

You will find the adapter intended for this conversion directly here:

5. FAQ for the Installation Guide

Question 1 – Can I continue to use my existing MINI rims after the conversion?

The rim diameter alone is not a reliable indicator for this. With the 330 mm brake system, the shape of the wheel hub is crucial because the 4-piston fixed caliper can take up significantly more space. Therefore, the desired rim should already be mounted during test fitting, and the clearance should be checked over the entire circumference. If the rim touches the brake caliper, it should not be used. If necessary, a technically permissible wheel spacer or another rim is required.

Question 2 – Does the brake conversion need to be registered with the TÜV?

For use on public roads, an individual approval in accordance with § 21 StVZO is generally required according to Epytec's information. Article 1321 is offered with corresponding technical documents for approval. It is still sensible to discuss the planned conversion, including brake caliper, brake disc, pad, brake line, rims, and possibly spacers, with the responsible inspector beforehand. This way, you can avoid unnecessary changes to an already completed system later on.

Question 3 – How long do the Megane RS brake calipers and MINI GP2 brake discs last?

The lifespan depends heavily on driving style, pad choice, temperature exposure, and area of use. For a used Megane RS brake caliper, you should not rely solely on the external condition. The key factors are smoothly operating pistons, intact dust boots, sealing piston seals, and pristine threads. The brake discs must be regularly checked for wear, cracks, significant grooves, and thermal damage. Especially with sporty use, shorter inspection intervals are sensible.

Question 4 – Can the conversion be reverted to the standard brakes later?

Yes, the design of the Epytec adapter is fundamentally reversible. According to the product description, no changes to the wheel bearing housing or steering knuckle are necessary for adapter installation. Therefore, keep the disassembled original parts clean and distinctly assigned. For a later reversion, wear parts like brake discs and pads should be checked for their condition again. During reinstallation, the respective manufacturer's specifications for screws, torques, brake lines, and brake fluid naturally apply again.

6. Safety & Liability

Safety first!
Always wear protective glasses, especially during grinding or drilling work.

The brake is a safety-related component - if you are unsure during the conversion, have the work carried out by a specialist company.

Note on registration:
The conversion is registrable, a material certificate is included. Please clarify with the inspector beforehand for the TÜV approval.

Disclaimer

Please note that carrying out this installation is at your own risk. Epytec assumes no liability for damages or injuries resulting from the implementation of this guide. Make sure you understand all steps and take the necessary safety measures.

And done! That's it!
We hope you have successfully installed everything now. If you have any questions or something is unclear, do not hesitate to contact us.

➡Here you can go directly to the contact form (click here)

About Epytec

Epytec is a leading specialist in the manufacture of tuning adapters with more than 15 years of experience in the industry. Our products, which are fully manufactured in Germany, stand for quality and innovation.

With our adapters, you can, for example, adapt a Porsche brake to a Golf or install an Audi engine in a T3 - TÜV-compliant and 100% fitting.