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Michael V.
Is the larger master cylinder required to use these brakes? Are there any downsides to using it without the larger master cylinder if it’s not required?
When upgrading to a big brake kit on Jeep JK/JKU, it is highly recommended and often necessary to upgrade the master brake cylinder.
Here's why:
Increased Fluid Volume: Big brake kits typically have larger calipers with more pistons. These larger calipers require a greater volume of brake fluid to operate effectively. The stock master cylinder might not be able to supply enough fluid, leading to a soft or spongy brake pedal feel and reduced braking performance.
Maintaining Pedal Feel and Travel: A larger master cylinder bore can help maintain a firm and responsive brake pedal feel with the increased volume demands of the big brake calipers. Without an upgrade, you might experience excessive pedal travel before the brakes engage properly.
Ensuring Optimal Brake Performance: The entire brake system needs to work in harmony.
Upgrading the master cylinder ensures that the increased clamping force and heat dissipation capabilities of the big brake kit can be fully utilized, resulting in the intended improvement in stopping power and brake modulation.
What to look for in an upgraded master cylinder:
Larger Bore Diameter: The new master cylinder will typically have a larger bore diameter than the stock one to displace more fluid with each push of the pedal.
Compatibility: Ensure the upgraded master cylinder is specifically designed or recommended for your Jeep JKU and the big brake kit you've chosen. Some big brake kit manufacturers may even offer or recommend specific master cylinder upgrades. In summary, while some smaller big brake kits might function with the stock master cylinder, it is generally best practice and often essential for optimal performance and safety to upgrade the master brake cylinder when installing a big brake kit on your Jeep JK/JKU. Always consult the manufacturer's recommendations for your specific big brake kit.
Here's why:
Increased Fluid Volume: Big brake kits typically have larger calipers with more pistons. These larger calipers require a greater volume of brake fluid to operate effectively. The stock master cylinder might not be able to supply enough fluid, leading to a soft or spongy brake pedal feel and reduced braking performance.
Maintaining Pedal Feel and Travel: A larger master cylinder bore can help maintain a firm and responsive brake pedal feel with the increased volume demands of the big brake calipers. Without an upgrade, you might experience excessive pedal travel before the brakes engage properly.
Ensuring Optimal Brake Performance: The entire brake system needs to work in harmony.
Upgrading the master cylinder ensures that the increased clamping force and heat dissipation capabilities of the big brake kit can be fully utilized, resulting in the intended improvement in stopping power and brake modulation.
What to look for in an upgraded master cylinder:
Larger Bore Diameter: The new master cylinder will typically have a larger bore diameter than the stock one to displace more fluid with each push of the pedal.
Compatibility: Ensure the upgraded master cylinder is specifically designed or recommended for your Jeep JKU and the big brake kit you've chosen. Some big brake kit manufacturers may even offer or recommend specific master cylinder upgrades. In summary, while some smaller big brake kits might function with the stock master cylinder, it is generally best practice and often essential for optimal performance and safety to upgrade the master brake cylinder when installing a big brake kit on your Jeep JK/JKU. Always consult the manufacturer's recommendations for your specific big brake kit.
Michael S.
Will I need to upgrade my back brakes also? I'll be towing with my 2015 JKU
We'd recommend you upgrade all four wheels to a truck and tow package or big brake kit.
John M.
Will this fit my 2016 jk wrangler unlimited with factory rims
If it is on 17" or 18" JK wheels that are not the Mopar moab wheel design. That style is the five larger uniform spokes. Other Mopar wheels should be okay.
Jason B.
Just installed. So far, so good. When I need to replace the pads and or rotors, what parts do I use?
Please refer to page 1 of your installation instructions. The part numbers are listed for everything that is in the kit for replacement.
Thomas M.
On the Crown Big Brake Kit, what is the part number for the calipers. I have a 2015 Jeep Wrangler
The left is 68157611AA and the right is 68157610AA
Scott M.
Is there a matching rear set available?
No, there is not.
Dona B.
Do you know the specs or part number to the big bolts for the cailpers?
The caliper bracket bolts (shown in the center of photo) are 68048467AA
Larry P.
can i use the same speed bleeders from oem calipers?
Yes, you sure can.
Edward H.
Can you give me the OEM # for the replacement rotor? These brakes are awesome by the way
Yes, the replacement rotors are RT31046 (Mopar #68040177AA)
Edwin I.
What Master Cylinder upgrade is recommended for this big brake setup?
The master cylinder that is recommended for best performance is #68091278AB , this can be located in the "Our Experts Recommend" section.