One of the few hidden quality improvements over the Lincoln offering appears to be a Treadle-Vac master cylinder displacement rod made of stainless steel. Lincoln used a chrome-plated steel bar. From the looks of it is just a thin layer of chrome that is applied to the bare steel, or it may have a substrate I can't see. It appears that the chrome is applied and the bar centerless ground and polished.

The slightest breach in the chrome opens an attack on the steel below. As rust physically "blooms", like a flower, it expands with such force that it breaches the chrome layer and peels super-sharp slivers up to greet the soft new rubber seals. The first pass ruins everything. It happens because water is a very small molecule. The reserve is open to atmosphere so the level drops when fluid is needed. Each time the fluid expands or contacts air is pushed in or out of the reserve bringing in new air containing moisture, which oils absorb.

Without taking the MC out you can simply remove the lid and remove the tip switch. Once you drain or pump most of the fluid you can pretty much see the length of the piston. By applying pressure to the pedal the bar moves into the critical section that rubs on the seal, but, if you can see rust anywhere you have it, or will have it in the critical area affected by the seal.

I'm about to post an open source design for seat belt attachment points. I'll do an open source drawing for a stainless steel rod. I'm pretty sure you'r goin to want one if yours is chromed steel.

If your tip switch is not tipped with the pedal fully retracted your TV is not working properly. It's designed to open the passage and let in new fluid if there's leak in the system. Closed off the level in the master cylinder drops with no replacement.



I'll have a drawing soon.