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Brake Components >Mopar J8 Master Cylinder and Brake Booster - JK Automatic Transmission

Mopar J8 Master Cylinder and Brake Booster

JK Automatic Transmission

Product Resources

Customer Reviews (6)

Questions (11) Answers (11)

Fitment Details

Features & Product Details

Have you swapped in the Mopar Big Brake kit (#77072434), one of those super trick TeraFlex Delta brake kits (#4403450) or some other brake kit needing more fluid? If so, the Mopar J8 Master Cylinder and Brake Booster kit is for you!

Jeep Jk Mopar J8 Master Cylinder & Brake Booster Features:

Performance brake booster

Big 1-1/8 inch master cylinder bore

Increases brake force

Designed for Heavy-duty axles

Straightforward installation

Boost the Performance of your Jeep's Brakes Mopar began as a family owned business that eventually transformed into a trusted brand to provide you with products that are 100% guaranteed authentic, brand new, and first quality. Their J8 Master Cylinder and Brake Booster is no exception to this as it features high-quality materials for long-lasting functionality. The purpose of this cylinder and brake booster is to make it easier for your Jeep to brake by increasing the force exerted without the need for additional force applied on the foot pedal. This keeps you safe during both daily driving and off-road applications, so you can stop your vehicle the way it was intended to stop.

Notes:

Same OEM parts included in Mopar's Big Brake Kit (P5160051).

Fits automatic transmission only

Does not fit with underhood ARB twin compressor mount

***THIS IS A MOPAR PERFORMANCE PART AND IS SOLD AS IS, THIS PART CARRIES NO WARRANTY FROM MOPAR

Product Resources

Customer Reviews (6)

Questions (11) Answers (11)

Fitment Details

Specifications

Brand: Mopar

Type: Master Cylinder

Mfgr. Warranty: No Warranty

Condition: New Product

Return Policy:

Standard

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REVIEWS & CUSTOMER MEDIA

6 Reviews

4.8 out of 5 Stars

5 Stars

(5)

4 Stars

(1)

3 Stars

(0)

2 Stars

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1 Stars

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Customer Photos and Videos

No user media. You can upload a photo or video of your install by posting a review.

Works wonderfully 9 months ago

5out of 5stars

Brandon
I installed a Grow big brake kit only to realize that was a useless upgrade with out a larger booster/master upgrade. Install is a big pain but a competent DIYer should have no problem with. I installed this in a manual trans with a Wilwood remote res, Evo compressor mount and ARB High Output Single, it all fits

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Will need a custom bent brake line for 2018 Jeep JKU. 9 months ago

4out of 5stars

IndioN8
Everything was going great until it came time to re-attach the factory brake lines. 1 line fit perfectly and the other one was off 1 3/4in.

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J8 brake booster install. 10 months ago

5out of 5stars

JKJV
I installed this in my JK with the intention of adding a big brake kit. To install I had to separate the cylinder from the booster as it would not slide in together, removal of the ABS hydraulic unit was not necessary. If the cylinder isn't installed straight on the rod it will bend the rod or ruin the piston inside the cylinder. 2 steel lines to the unit did have to be rebent to fit the cylinder as it is 1 and 1/4 or 1/2 inches longer than the stock assembly. I bled it by installing the assembly and routing the lines back into the reservoir and using the brake pedal. I did not want to deal with a vice and screwdriver to bench bleed. I did a complete brake overhall with Teraflex Delta brake kit as well as added steel braided lines so overall braking performance increased.

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1 of 1 people found the following review helpful

Mopar BBK is the answer you are looking for... 2 years ago

5out of 5stars

Jcs2179
If you have finally decided to upgrade your factory Jeep Wrangler brakes to handle the extra weight of that suspension upgrade, the bigger wheels, heavier tires, bulky roof rack, winch, fridge, and bumpers, you have no doubt purchased one of the good quality kits from the Usual Suspects. None of the kits however, tells you about the soft/mushy pedal you'll get as a direct result of the bigger volume of brake fluid you will be pushing through the system, but with nowhere to pull this precious resource from. Its just simply not there. The kits mention nouns like might, maybe, sometimes, but the real deal is if you want those expensive upgraded brakes you just bought to perform their best, you MUST get this kit. The reservoir is much bigger, the M/C has bigger bore size to pass more fluid through, and the bigger brake booster...well, it boost!! Its instant stopping power. A word of caution: you must bench bleed the M/C prior to installation, and the kit does not fit if you've installed the ARB dual/single compressor and braket under the hood. The Mopar BBK kit is dimple a bit bigger and it won't fit.

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1 of 1 people found the following review helpful

'14 Rubi w/ J8 2 years ago

5out of 5stars

Power Steering Upgrade
I installed UD60's on my 14 JK Rubi, the brake rotors and calipers on the UD60's are huge and I wanted to make sure the mc and brake booster were adequate for the massive brakes. After installing the new mc and brake booster I couldn't get the brake pedal to firm up. I bled the brakes every way possible and had the anti lock module bled as well and yet the brake pedal would continue to go all the way to the floor. I contacted Northridge 4x4 and they sent me a replacement mc and brake booster right away. The first kit that was sent didn't have a new seal with it, that goes between the mc and brake booster. I was instructed to use the oem seal which I did, and would later determine that that's what was causing the issue. The second kit that was sent did indeed have a new seal, after installing that kit, the brakes are better than when the jeep was new. Aside from the snafu with no seal being with the first kit, this setup is fantastic.

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QUESTIONS & ANSWERS

Q: J8 booster and MC FIREBALL4 months ago
Will this fit a 2018 Wrangler JLU automatic?
- 0 of 0 people found the following answer helpful
  A: This is JK specific.
  Northridge Chris @ Northridge4x4 4 months ago
  
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Q: 2012 jk auto Blakebb26 months ago
Will this product fit my vehicle
- 0 of 0 people found the following answer helpful
  A: Yes, this will work for your 2012 JK auto, without issue.
  Northridge Chris @ Northridge4x4 6 months ago
  
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Q: Compatibility with 2014 JKU jespersen701 year ago
I have a 2014 JKU and I installed a Teraflex front big brake kit, I would like to install the Mopar J8 master cylinder and brake booster but it says it’s not compatible with 2014 only 2015 to 2018. Why is this kit not compatible with 2014? What is different and can I make it work? Thank you
- 0 of 0 people found the following answer helpful
  A: As long as you have an automatic, this will work for you without any issues.
  Northridge Chris @ Northridge4x4 1 year ago
  
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Q: J8 booster / master cylinder with synergy bracket Collin1 year ago
Will this work with the synergy compressor bracket and single (small) ARB compressor
- 2 of 2 people found the following answer helpful
  A: This will not work with the Synergy compressor bracket. You have to relocate that in order to use the bigger brake booster system.
  Northridge Chris @ Northridge4x4 1 year ago
  
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Q: J8 MC +Booster with powerstop? prestonseaver2 years ago
Will this kit work with the powerstop factory replacement sized calipers, or will the pedal not feel right since the calipers are not as big as the BBK?
- 0 of 0 people found the following answer helpful
  A: Yes, this will improve your braking.
  Northridge Chris @ Northridge4x4 2 years ago
  
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