Jump to content

Master Cylinder upgrade


Recommended Posts

I have searched high and low and cannot find the right information. 
 

i’m doing a swap from the stock MJ master cylinder to a ‘04 WJ master cylinder. What thread pitch and flares do i need on each of the MC lines and what are my best options to get there? 

I pulled a donor MC from picknpull and have yet to actually begin the swap simply due to missing this information. 
 

Thanks!

IMG_5083.jpeg

Link to comment
Share on other sites

  • cdtx_2011 changed the title to Master Cylinder upgrade

You are going to have to make your own brake lines to connect the MC to the prop. valve.   The best thing to do is to take the MC to the auto parts store to match up the correct kinds of flare and thread.   On a WJ, they might be using ISO “bubble” flares, and it is easier to buy the tubing with those flares pre-made.

 

For the other end that connects to the prop. valve, be prepared to cut and bend the tube to create the custom lines you need and flare the ends with the traditional flare that attaches to the prop. valve.  (You can reuse the regular flare nuts from your old tubes on the ends that connect to the prop. valve)

Link to comment
Share on other sites

This is why I always recommend folks grab the master from the junkyard with the lines. They're flexible and all you need to do is change the BUBBLE flare on the line to DOUBLE flare to adapt to the prop valve. 

Link to comment
Share on other sites

They will be ISO bubble flared; M10x1.0 and (I believe) M12x1.0

If you don't want to flare your own lines, you can buy brass adapters to step down to 3/16" line and SAE double flare and use a pre-made line.

Link to comment
Share on other sites

2 hours ago, ghetdjc320 said:

X2 on the fitting sizes. I’ve used adapters but you can also just grab the fittings and make your own master to prop valve lines and use the copper nickel material.

Copper-nickel is the best.  

I'll also say that bubble flares are easier to make than double and with a tiny bit of research you can simply get the correct fittings. 

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

×
×
  • Create New...