Master Cylinder

Master Cylinder


Jacksonville North Carolina
1974 CJ5.
I am trying to bleed my brakes. I have air in the system, so I am chasing bubbles. I have heard of guys using mid 70's master cylinders as swaps in the CJ's
Has anyone done this?
I don't know about the mid 70 master cylinders. I just up graded my master cylinder with a YJ master and booster and it seems to work just fine.
Save yourself some grief, buy speed bleeders, they sell them at most autostores, it'll be on the isle with all the misc. parts, like door handles, window cranks, misc :dung:.
If you ask the parts monkey's they may not be of help.

But a speed bleeder replaces your stock bleeders and has a spring and ball to open and close to help the bleeding process. Simply crack the bleeder, put a length of hose on it and into a container, a few pumps and your done, tighten the bleeder and roll. Just keep an eye on the fluid level, you can do this with the mastercylinder cover off but pump slowly or brake fluid will go everywhere. Also use those silicon vaccum caps like in the ricer section to cover the speed bleeders to help keep them clean.

And if your looking for more braking power the YJ brake booster is the way to go.
Several companies sell kits if your not looking to piece it together, check out
mine will not bleed right if i dont have a tool on my proportioning valve. i also went to harbor frieght and bought a vaccum pump bleeder for $20.
I usally have good luck with gravity bleeding.Just leave the bleeders completely out for a little bit until fluid comes out.Then bleed as you normally would.Usually about 3 times with the pump/hold open/close method.
Save yourself some grief, buy speed bleeders,/

I got them a few years ago for the rear brakes, but one doesnt work for some reason, so back in with some cheaper tried and true bleeders. My kid will just have to be pulled away from his X Box to help bleed them.:D

I'll look at the YJ MC
chasing down bubbles, humm, have you tried bleeding the master cylinder independent of the rest of the system? A lot of trouble can be handled by doing what is called a bench bleeding, you basically bleed the master cylinder into itself. It can be done in the Jeep and not on a bench like the name suggest. This sets up the "master of the system" to be working in top form and is a solid base to a properly working system. Not doing such can leave you with a spongy pedal that you try to cure by bleeding and bleeding the system when it is acutally a few bubbles in the master cylinder you need to get cleared. Hope this works, it can save a lot of trouble.
I have bled the MC & the lines. I have tightened the adjusting srew for the pads also.

I am sure I know what my problem is now. I swaped a Brake booster and clutch/brake pedal asymbley out of a new model jeep. I thingk it was out of a CJ7.

The problem is, the plunger only moves in about 1/4 of an inch when the pedal is pushed to the floor. The pedal moves 1 inch before the lever butts up to the plunger in the Brake booster . So I have to fix that and I should be good.

Also I am going to swap out the MC for a 78 Mercury Marquis, with 35's I hear that is a good swap.

Those with this setup, where did you hook up your vaccume to the block on a V8?
OK, I know what you are dealing with, the old rod not being the correct size thingy. I can tell you something you do not want to hear. There is a guy in Washington state. Has a Business, called Herm the overdrive guy, well he sells a kit for retrofitting a MC into old CJ-5s that does not need the rod adjustments. He does talk a lot and loves to talk on the phone, A call to him may get you some killer advice on how to cure that. Google Herm the overdrive guy. And check out his site for some killer conversions.

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