Tips on Master Cylinder Replacement

[007]

I'm getting ready to replace my master cylinder and vacuum booster... Any tips, gotchas, experience, etc. would be greatly appreciated...

 

[Dolamite]

Bench bleed the master cylinder prior to installing. Cover up any painted surfaces on your Jeep that you don't want stripped. Brake fluid is nasty stuff.

The brake lines connected to my master cylinder were rusted out pretty good. If you break one, you can rent a double flaring tool from Autozone for cheap.

 

[007]

Bench bleed the master cylinder prior to installing. Cover up any painted surfaces on your Jeep that you don't want stripped. Brake fluid is nasty stuff.

The brake lines connected to my master cylinder were rusted out pretty good. If you break one, you can rent a double flaring tool from Autozone for cheap.

How do I perform a bench bleed?


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[Dolamite]

The master cylinder I purchased came with two plastic plugs to thread into the master cylinder. I Installed the plugs, put the new master cylinder in a vice (carefully so as not to damage the unit), added some brake fluid to both chambers, and manually moved the piston in and out until no more bubbles were visible in the chambers when the piston was pushed in.

Make sure not to push the piston in too far. I think my instructions said no more than an inch of travel. If the piston is pushed in too far it will damage the unit.

There should be instructions that come with your unit. I think some master cylinders come with hoses that get routed back into the brake fluid in the chambers instead of plugs.

If I recall correctly, pushing the piston in and out repeatedly was more of a workout than I anticipated. There was significant resistance.

 

[007]

Well this is a "like new" Craigslist deal with a couple of different sized vacuum boosters and a new vacuum reservoir that I have NO idea how to plumb.


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[Dolamite]

Well this is a "like new" Craigslist deal with a couple of different sized vacuum boosters and a new vacuum reservoir that I have NO idea how to plumb.


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You will have to disregard my previous posts. My experience was only with the basic manual brake setup. No vacuum booster.

I'll have to defer to somebody else who has experience with power brakes.

 

[mtnwhlr]

You will have to disregard my previous posts. My experience was only with the basic manual brake setup. No vacuum booster.

I'll have to defer to somebody else who has experience with power brakes.

You bench bleed them the same so no need to disregard.

 

[gr8dain]

You bench bleed them the same so no need to disregard.

X2. I did my power brake MC and booster last year. Pretty straight forward. Connecting the pedal linkage back up at the firewall was a pita but with another person's hands I was able to get it done. Then had to bleed the brakes at the wheels after all was installed.


Dain