Hydroboost Free Play

[Mr Nick]

I purchased a new Bosch hydroboost unit. I noticed it has about 1/8" of free play at the pedal push rod, before the push rod that goes into the MC begins to move. This would result in about 1/2" of free play at the pedal before the brakes were applied.

Is this normal?

if so, would there be any harm in installing an up-travel pedal stop to reduce the free play?

[IMPALAMAN1]

does the master have a deep plunger hole or is it flush? some have an adaptor to fit. i.e. wilwood. Can you take up the slack at the pedal arm adjustment? are you going from not power assist to power? correct hole on the pedal for power?

[Mr Nick]

The free play is with the hydroboost unit not even installed.



Using the pic as an example, if I push in on the pushrod that would attach to the brake pedal arm (red arrow), it has about 1/8" of travel before the rod that goes into the MC begins to move (green arrow).

Now that I have it mocked up on the pedal hanger outside of the car, I can see that if needed, I could use the brake light switch bracket to add an up-travel stop. But I'll drive it as-is first before I mess with anything. That will be a while though, since I'm doing an engine rebuild at the same time.