Re: Easamatic Rebuild Sources

Posted by Ross On 2013/8/24 19:58:55

The vacuum seal is not affected by pitting of the bore as it is sealed against the face of the booster cylinder with a rubber ring. I have never seen a problem there in the dozens of units I have rebuilt.

What I have seen many times is incorrect assembly. One of the last ones I did had the hydraulic seal in backwards and the remaining seal pieces pretty much installed in random order to fill up the space. I was horrified I had driven the car around the parking lot in the vicinity of other cars. Can't imagine why it worked at all. Almost none of these units are virgin at this late date, and there is a plentiful supply of negligent idiots.

The other most usual failure modes are coagulated brake fluid from long inattention, seals just plum worn out, pitted pistons helping the seals wear out, and occasionally booster problems such as too much boost or not enough.

The treadlevac on my Packup now has about 5 years and 33K miles with no end in sight. If it starts drinking it will get another kit in the hydraulic portion (just like any other master cylinder)and a quick lube of the vacuum portion. I use normal brake fluid and change it ever 2 years or so.