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More on (moron) brake boosters ('72 '02 non-tii)


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So all along, I thought Schatzi's brakes were pretty good. Had new front rotors, pads and rear shoes installed shortly after I got the car, almost 2 years ago. Seemed to have good stopping power; more than adequate.  So much better than the brakes on my other car, a 1965 Triumph Herald with 4-wheel drums all around.  I was happy.  All was well in my world.


Then recently I read about "the test".  You know "the test": engine off, pump the brake pedal a few times, keep foot on brake, start engine. If the pedal goes down a bit, it means your booster is okay. So I performed "the test". AAAArrrrggghhhh! Pedal didn't move down at all. Dang!  After "the test", then "the search" started to find out why.  I pulled off the elbow on the booster (thanks to some FAQ advice last week on how to do it) and peered inside the booster. There it was: the dreaded reservoir of brake fluid, meaning my master cylinder is leaking. Per the sage advice on FAQ against rebuilding it, I ordered a new m/c. And luckily, I had picked up a spare booster awhile back, as mine is crusty and rusty on the outside and the price was good. 


So now, another project is before me: replace the m/c, booster, and all seals and hoses. Can't wait to deal with "the bitch clip" on the booster. But thanks again to FAQ, I have ammo in the form of good info on how to deal with it. Soon as all the parts arrive, I'll delve into it.


But I have one question before I start; the inside of the "new" booster is nice and dry and the rubber diaphragm looks soft and pliable. When I push on the piston, it appears that the diaphragm moves nicely against the inside of the booster walls. But it's dry. So, is there supposed to be any type of lubrication there for a better seal, or is it supposed to remain dry?


Thanks again to all (and Happy Thanksgiving),


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I've never heard of anyone lubricating the diaphragm or the pushrod--and you certainly don't want any petroleum-based lubricants on the rubber diaphragm.  The master cylinder should seal tightly against the booster body (IIRC there's a rubber or composition gasket between 'em) so there shouldn't be any leakage.




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