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Here's how i do it:

Drop a 1/8 ball bearing ball into the MC. use a narrow scale or depth gauge to measure from protruding bore of MC to small ball bearing. Subtract distance from MC flange to top of protruding bore. Add 1/8 inch (the size of small ball bearing). Add 0.030" for the clearence. Set power unit push rod to match the final calculation.

What is diameter and thread pitch of the gauge?????? What is diameter of Stem in power unit??? Is it easy enuf to determine the thread pitch of the stem of the power unit???

With those specs i think we can up a way to use the gauge IN CONJUNCTION with a a ball bearing ball.

It is 1/4-20 on the gauge. Power unit end is just a small rounded screw head --maybe 8-32 with jam nut to lock to rod. I think I am going to rework this tool. Round the end to fit in the cylinder bore well & adjust the thumbnut end to be the length of the side legs plus .025. That should do what I want with one adjustment--no fussing with anything else.

Sounds like a good plan to me. That 1/4 - 20 threaded gauge rod AS_IS would never give any kind of an accurate measureemnt. The 8-32 thread pitch on the power unit stem will yeild 0.03125" of movement on ONE COMPLETE turn.

On second thot. Lets do some calculation on the gauge.

What is the diameter of the recess in the MC piston that the power unit stem fits in to????

It just mite work as mfg'er says it will. But i kinda doubt it. Need to know diameter of recess in MC piston. From that we determine the extra distance a 1/4 bolt (threaded rod of gauge) will go into the recess.

I'll look at the cylinder closely tomorrow and check the diameter. I left it hooked up in the car and just removed the booster when I decided to make the new linkage.

The adjustment is probably OK but just one of those things I wanted to ensure was correct before putting things back together. Not happy with the amount of booster travel before brakes start to apply. I think it is more than it should be but don't have a good feel on what to expect.

I know there is no problem with cylinder-booster mismatch ie short rod and deep bore. Those dimensions are OK. While any misadjustment on the pushrod would not be enough to cause the issue, just re-verifying everything and that was on the list.

ok. We know that the gauge uses a 1/4" rod. IF the hole in the MC piston is 5/16" diameter (ergo assuming a 5/16" radius at bottom of hole) then the 1/4 inch gauge rod as is should yield the .030 extra travel and therefore no need for readjustment or compensation after it has been set.


EDIT: Not .030 extra travel but more like .062 extra travel.

Quote:
To measure the cylinder by screwing the gauge pin is step one. If thereafter the opposite gauge pin hits the booster rod before the gauge legs touch the booster or if there is too much space between gauge pin and booster rod when the gauge legs touch the booster, then an adjustment of the booster rod is necessary.
To adjust the gauge a second time wouldn't make sense.

If you really have to adjust the gauge a second time to determine the correct distance then the gauge design is in need of improvement (to put it lightly).

See my edited calculation correction to my post #17 above.

I went back and looked at the pics in page 1. Notice that one end of the gauge (short leg end) is for measuring MC. The LONG leg end of tool is for setting the POWER unit.

I guess everyone else saw that except me.