Brake Components
My 88YJ/CJ has been sitting for 15 years, so I was definitely replacing the master cylinder. And I also wanted to replace the 33 year old proportioning valve that was for disc/drum, since the rear 8.8 axle has disc brakes.
So, it was a pretty easy decision to also upgrade to a dual diaphragm brake booster. I am basically using the same parts as I used on my 95 YJ back in 2019. The components are based on a C3 Corvette, and are commonly used in hot rods, etc:
I pieced together all the parts from a few places. There are specific YJ kits that you can buy, but they are very, very expensive:
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| Booster and Master Cylinder |
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| Proportioning Valve |
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| Adjustable Pedal Rod |
The 88 YJ was originally a manual transmission car, so it had a small brake pedal. So, with Juan's help, I bought a new (used) automatic transmission brake pedal assembly that has the wider pedal. The automatic brake pedal assembly is from a later YJ, so I also needed the brake pedal retaining clip.
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| This was very clean, and was later painted gloss black. |
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| These tend to break when removed, so I bought an extra! |
Unfortunately, the pedal rod that I purchased doesn't fit. It's bushing is about 9/16" ID and the post on the brake pedal is 1/2".
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| Too loose! |
I looked (and looked, and looked some more!) for a different pedal rod that may fit directly, but didn't find anything. There are multiple solutions to this problem, but the easiest was just to make a new brass bushing on the lathe.
Brass Bushing
This was a good cold weather project that I could finish with the garage door closed! Here are the steps I did to make the bushing. It's a simple little part. I already had the brass stock:
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| Turning down to diameter |
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| Checking fit |
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| Faced off flush with the bracket |
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| Hole drilled |
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| Part reversed and parting off the extra |
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| Parting complete |
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| Facing the flange to dimension |
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| Finished! |
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| Test Fit |
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| Test Fit with Retaining Clip (only partially installed!) |
With the bushing complete, all the brake components can be installed on the firewall (brake pedal, booster, master cylinder, etc.)
