another brake question- coming out of long storage

[rfuerst911sc]

The 1975 rolling chassis I purchased in December has been off the road since 1991. The car has been stored inside all that time but it appears it hasn't had brake fluid in it for a long time. I am converting to 911 front struts,brakes,rotors etc. and will rebuild the rear calipers. My question is regarding the master cylinder, after all this time is there a chance it's still good? Until I remove the bottom cover and look around I don't know what it looks like. I assume if it is "dry" with no fluid in it I can assume it's toast? Worth rebuilding or just purchase another? Suggestions?

[Dave at Pelican Parts]

I'd just get another one pre-emptively. It is very unlikely to have no brake fluid in it--some almost always gets left behind when you drain the system (intentionally or otherwise). Any fluid that is there will suck water out of the air, and will rust anything rust-able it sits on for too long.

Rust + precision-machined surfaces == Bad News.

--DD

[rfuerst911sc]

Dave in your opinion is it worth the "upgrade" to go with a 19mm master cylinder or stick with the stock 17 ? I will be running 911 M calipers up front and either stock 914/4 or 911 M in the rear. Thanks for the feedback.

[Tobra]

Larger MC will move more fluid for the same amount of pedal travel, which translates into more braking for less pushing, firmer pedal. Can't remember the formula, but I seem to remember area squared in there somewhere, so you can get a pretty significant change.

I personally would stay with stock rear calipers, as most of braking is from front and stock rears should be adequate. You will want to rebuild them or what i would do is get some Eric rebuilt. Rebuilding brake calipers is not my idea of fun though.

[Dave at Pelican Parts]

If you've got 911 calipers, use the 911 (19mm) master cylinder.

--DD

[Nostril Cheese]

you dont want the stock 17mm cylinder in there anyway. Very soft pedal. The 19mm is a direct bolt in swap and really makes a nice difference in feel. Just bleed the system well. I use the ATE Super blue and just pump the brakes until nothing but blue flows out.

[Tobra]

I will be putting a 19 mm master on my otherwise stock 914 when I put the rebuilt calipers on it. I don't know why you would not do this. I think I might like the vented fronts, seems like it would be worthwhile.

[Dave at Pelican Parts]

The only difference is feel, really. I am now quite used to my 19mm MC, but I don't think I'd have a problem with the 17mm one, either. You have to push 25% harder with the 19 to get the same braking force as with the 17, but the pedal moves 25% further with the 17 than with the 19... The pedal feels harder, but the only thing that's changed is the "leverage" between your foot and the brake pads.

--DD