Master cylinder question?

[rabbitude]

My car came with an upgraded 25mm master cylinder. The pedal feels absolutely amazing, super firm. But I am having issues with the height of the pedal. My other E30's with the stock setup had quite a bit of travel with the pedal. The braking pressure was modulated by pedal height. With the 25mm braking pressure is modulated by pedal pressure not height. The issue is the pedal is way too high to heeltoe during down shifts. The pedal has about half an inch of travel and then its just a rock. With the stock setup the pedal would travel to the point it was almost equal height to the gas pedal. Any sugestions, I dont want to go back to the stock master cylender but may be forced to if I cant find a solution. Can you adjust the pedal height.

[jlevie]

There should be an adjustable link between the pedal arm and brake booster. You can use it to lower the rest point of the pedal.

[N8857E]

There should be an adjustable link between the pedal arm and brake booster. You can use it to lower the rest point of the pedal.

I have a question concerning this adjustable link. Is this the same link that is adjusted for the brake lamp switch? I was unaware that you could adjust pedal travel, or 'feel' by adjusting this link. I posted a thread about a stiff brake pedal and little travel a few weeks ago, and maybe this might be a start?

Any input would be great.

[Wh33lhop]

I have a question concerning this adjustable link. Is this the same link that is adjusted for the brake lamp switch? I was unaware that you could adjust pedal travel, or 'feel' by adjusting this link. I posted a thread about a stiff brake pedal and little travel a few weeks ago, and maybe this might be a start?

Any input would be great.

No. The brake light switch is a little plunger that you can "reset" by pulling it out further. The adjustable linkage is between the pedal and the master cylinder.

[N8857E]

The adjustable linkage is between the pedal and the master cylinder.

If memory serves me correctly it looks like a square U shaped adjuster fitting with a hole for the pin to go through it?

[Wh33lhop]

Yep.

[N8857E]

Thanks.

I'll give it a whirl to see if I can get the pedal travel to increase, and the feel to soften up. Right now it has a very short travel distance, and then just gets rock solid and not-so-great stopping distances.

[Wh33lhop]

Thanks.

I'll give it a whirl to see if I can get the pedal travel to increase, and the feel to soften up. Right now it has a very short travel distance, and then just gets rock solid and not-so-great stopping distances.

The solidity of the pedal isn't going to change, just the physical point at which you reach it. If you don't like how solid it feels, then just revert back to a stock 22mm master; it's not going to soften up.

The whole point of the 25mm master is that it decreases pedal travel and gives it a firmer feel. You're dealing with a 30% increase in master cylinder area, pedal travel is going to decrease by about 30% as you have less hydraulic "leverage". However you do not actually have to press harder (well, not by much) on the 25mm cylinder to get the car to stop as quickly, it will just feel like you're pressing harder since the pedal doesn't give as much.

I've got a 25mm out of an E32, I like it. Still have some air in there somewhere so I haven't gotten to "really" test it out yet, but I like the pedal feel. SS lines are next.

[rabbitude]

How much of a pain in the ass is it to adjust?

[N8857E]

Gonna have to get underneath driver side dash, pop the square tamper marked cir-clip, push the retaining pin out and shorten/legnthen the square u-shaped adjuster fitting to your liking.

[jlevie]

Actually, it isn't necessary or desirable to remove the pin from the clevis. Loosen the jam nut and turn the threaded rod via the flats provided at the booster end of the rod.