Hard brake pedal feel

[Kevin Saunders]

After the last fluid flush (1977 911S) I noticed that the brake pedal is hard to depress, feels like I am stepping on a brick. The car stops well and doesn't pull.
Could it be a stuck piston?

[darrin]

kevin, do you have perspective on how a "dialed in" '77's brakes should feel -- they are pretty stiff by design. Seems a stuck piston would cause pulling. Can you lock up the tires? will let others weigh in on brake booster troubleshooting/etc.

[DanMan68]

I have a 77 with the power booster, new pads / rotors, rebuilt calipers, recently bled. The brakes are very “stiff” in that not much travel or feeling of slop exists in the system, but at the same time not much force is required to stop and I have very good feedback. Personally the best brake feeling I have ever experienced. Do you have the power booster or are they the manual brakes?

[spuggy]

All 77s came with a booster, I'm told - another first/one-year only thing for the '77.

I used to think the '77 930 wasn't boosted - until I sold my original servo to a guy with an all-original car about 10 years ago - same part #.

His had failed. They can and do, although they don't often. Probably why the replacement cost is up there...

Way back when, I was always told that the way to check servo operation is to put your foot on the brake (pedal should be high and hard) and start the motor - if the pedal moves and gets softer, servo is getting/holding vacuum.

Hopefully, if yours fails the test, it'll be something easy - like the big vacuum hose springing a leak, collapsing/getting pinched or popping off. They can get pretty crusty-looking after 40-odd years..

[lsf911]

Kevin,

As others have said above, I think it's normal for the brake pedal to feel that way.

I have an 83 and the pedal is rock solid. Doesn't move much but stops the car well.

[sugarwood]

Hard as a brick is exactly how you want it to be.
The 911 has the best brake feel of any car I've owned.

This is exactly the reason you flush your fluid.
To remove air and water that makes the pedal feel spongy.

[Kevin Saunders]

I have owned the car for 11 years and it has always had a softer feel to it. Perhaps I have finally got all the air out of the system. I do notice when I start the car that the booster is working. The car does stop well and straight and I can lock them up. I suppose that having never driven another air cooled car perhaps this is the norm. I also have a 981 Cayman which is a different story altogether. Thanks everyone for the help I have a lot more confidence in the car. Happy New Year and Happy Trails to all.

[Dr J]

Here is an easy test. As you are close to a stop but with the car still moving, with clutch disengaged, turn off the car while pressing on the brakes. When the brake booster is not operating (i.e. engine is off), the difference is obvious. Make sure you have plenty of space in front of you when you try this!

[911 SLANT]

I just bleed my 930 brakes and they are rock hard maybe half inch from top.