Sorry, this is kinda long but also kinda interesting (well to me anyway, hopefully to you all too ).

So I’ve been struggling to get my brakes back to proper working order for some time on my 73. All started while noticing what appeared to be a leaking MC or PB from viewing these parts from under the car (bottom of booster was rusty, was wet). Thus I started a journey of replacing various brake components on the car that that has included all the short brake lines, distribution block and calipers. I’ve gone through a few power booster/MC combinations with varying results (fitment issues, leaks, etc.). My latest combo was from NAPA but MC seemed to have a leak, so NAPA replaced the MC but with one had a smaller diameter hole vs. the one I exchanged. I happened to have a new larger diameter part so I swapped them (napa unit PB came with short fixed push rod and adapter piece for deep hole MC). Well to my surprise the brakes started to engage while driving without apply the brake pedal!? My guess from reading all the blogs on this the issue was push rod length. The NAPA push rod length is fixed (short push rod, large hole adapter cylinder). How frustrating!

I have been replacing stock parts (MC/BP, intake, exhaust manifolds, distributor, etc.) and storing them on the shelf and got the idea from the Lonestar brake caliper folks in Texas (another story there ) to send my original PB to Booster Dewey’s in Oregon to have them rebuild it. So that’s what I did and as I’m in Washington State the turnaround was one week. The thing I noticed about the original booster is that it has a long push rod with the adjuster nut on the end that goes into the deep hole on the MC. All the other ones I got had a short push rod and an adapter cylinder that went into the deep hole MCs. After measuring the NAPA MC dimensions against the factory MC, I found them to be identical. My next challenge was to reinstall factory retaining clip that goes on the shaft that goes through the PB clevis and brake pedal under the dash.


How did GM do that I wonder, must have had a special tool as it’s a “needle nose plyer” type install due to the limited space involved. I’m guessing this is why many of the replacement parts come with a shaft with hole in it that uses a cotter pin!? The problem with the clip is that one side is pushing on the head of the shaft such that one would have to somehow apply pressure on the outside of the clip to push it onto the slot on the head of the pin. It’s actually kinda of a neat part on how it works but a PITA to get on. So I’m thinking I have to spread that sprung steel part that pushing on the shaft’s head away somehow to get the clip over the shaft to push it on. So I’m looking around the garage to see if I can find something that will accomplish this task and this is what I came up with:



Kinda of a bubba tool but it worked great! I could not believe it, after 30 minutes of frustration (BTW, I’m starting to get used to being frustrated working on this car, LOL!) it took all of about 2 minutes to get the clip on. And yes those are golf tees, the wood sinks into the sharp metal edge of the clip and holds pretty good. And while the brake pedal still seems a little low to me it’s not to the floor (can put my foot between pedal and floor). Also, with foot on the pedal and I start the engine, pedal only drops about ¼” so from what I’ve read that’s good, right?

So I think I’m good now and will re-bleed the brakes again after I change out the LR caliper to see if I can get a higher pedal (LR has a broken edge on outside bleeder, doesn’t leak except when bleeding the brakes, thus the call to Lonestar Calipers in TX).