3.2 Carrera brake question

[flyingplatypus]

When I'm braking in my 3.2 I have a strange feeling in my brake pedal and was wondering if it is normal. For the first half of the braking it is pretty soft and has a lot of travel. Softer than I prefer actually. But, in order to get the brakes to lock I have to use a pretty good amount of force, but when I do it actually has a different feel, and gets significantly firmer with less travel. Basically it feels like the brakes have two stages. Is this normal? Or, is this just a quick of these cars? Thanks!

[GH85Carrera]

No, that is not really normal.

The brake pedal feel is one of the many thing I love about my 85 911. It is very precise. I just did a track day last week at Hallett raceway. It is a super technical track, and one of my favorite parts is a challenge to get just right. Coning up over a hill, in third gear running to redline and coming up to the "bus stop" corner I nail the brakes hard and drop from 90MPH to about 40 in the shortest distance possible making the tires chirp as the weight shifts from the bumps. Never a lockup, just on the edge of traction, and of course with no ABS is is hard. Doing that for 20 minutes, as well as the rest of the track is just a blast.

[Bill Verburg]

Originally Posted by flyingplatypus

When I'm braking in my 3.2 I have a strange feeling in my brake pedal and was wondering if it is normal. For the first half of the braking it is pretty soft and has a lot of travel. Softer than I prefer actually. But, in order to get the brakes to lock I have to use a pretty good amount of force, but when I do it actually has a different feel, and gets significantly firmer with less travel. Basically it feels like the brakes have two stages. Is this normal? Or, is this just a quick of these cars? Thanks!

What you are feeling is the effect of the p/v on the rears The p/v cuts in at 33bar line pressure


Below that point called the 'knee' the line pressure is split in the ratio 1.3 favoring the front, above that point the line pressure is split in the ratio 1.91 both favoring the front.

hydraulic feel is all about the ratios, effectively the front ratio above 33bar means a bit harder pedal, it's just like using a bigger m/c

[BER]

I agree with Glen, what you describe is not normal or at least it is a heck of a lot different brake feel than on my 84 911.

Do you know when the last time your brake system was flushed with fresh brake fluid. If it was not in the last year or so, I would suggest a complete flush of your brake system and see if the feel of your brakes improves. If not, then you could look at the master cylinder and calipers for more serious issues. My hunch is a good brake system flush will solve your brake feel issue.

[JohnTucker]

My '84 has pretty amazing brakes given the year made. Similar to what you describe...you need to use some force. Normal driving is pretty gentle brake pressure...but if you stomp on the pedal, it can easily lock up the fronts. And I've got brand new shoes on the car...so it's not the rubber.