Clutch on M5

[viktor_k]

Hello, question about clutch, does m5 have a simple hydraulic clutch? or is there a pump involved like in power steering? I ask because when the motor is not running the motor doesn't seem to hook up to tranny until it is almost completely depressed, but when the motor is running it starts to grip very early.

Anyone notice this?

I hypermile my other cars quiet a bit by killing the motor as much as possible (while being safe), a little tricky in M5, but could actually be better if i know what exactly is going on.

 

[thaxman]

Pretty sure this has a hydraulic clutch with a slave cylinder that uses brake fluid and the brake booster.

 

[viktor_k]

Ok, thanks, a followup question, in my 5, the clutch picks up about mid point. To start the car, you need to hit the switch at the bottom, but to do the rest, do folks still do a full press/depress every time?

 

[Silentnoise713]

Ok, thanks, a followup question, in my 5, the clutch picks up about mid point. To start the car, you need to hit the switch at the bottom, but to do the rest, do folks still do a full press/depress every time?

+1 to thaxsman.

Not sure if I understand you question but the clutch engaging mid point is mechanical. The need to depress the clutch to start the car is electronic due to the safety switch on the clutch that won't contact unless the pedal is fully depressed. You can get around it by using a jumper on the switch to bypass this (do at your own risk).

Not sure what you mean by “but to do the rest”??

 

[viktor_k]

+1 to thaxsman.

Not sure if I understand you question but the clutch engaging mid point is mechanical. The need to depress the clutch to start the car is electronic due to the safety switch on the clutch that won't contact unless the pedal is fully depressed. You can get around it by using a jumper on the switch to bypass this (do at your own risk).

Not sure what you mean by “but to do the rest”??

yea I didn't do a very good job asking that question. I understand the electrical vs mechanical part of the clutch, i'm used to having the same tension on the clutch pedal all the way down to the metal as I press down on it. On this 5, it seems that it has 2 levels of tension, the first part goes down about half way, its a bit lighter to press, then the second part is harder to press, i usually don't depress all the way down through the second part unless I'm starting the car. I'm wondering if the two levels of tension is the hydraulics or maybe its a sign that the clutch is going to go out soon. Like mentioned before, the clutch bearing seems to be a bit noisy (enough for me to hear it sometimes).

Thanks for your help. It'd be nice to drive another 5 for comparison, but finding another 5 manual is pretty much like finding a needle in a haystack.

 

[DKaz]

I would depress the clutch all the way, seems like more effort to just push it to just past the friction point.

 

[Silentnoise713]

Ah ok. It’s been a few months since I sold my ’08 manual but I *think I recall the clutch having a pretty linear feel (I liked it a lot). Had a nice and firm feel (compared to the Fit’s featherweight clutch), improved after I bleed/flush out the whole braking/clutch system when I converted the brakes (shared).

Not knowing your maintenance schedule, I would recommend bleeding clutch slave first, or better yet flush the whole brake/clutch system. Do you notice any signs of leaks on the clutch slave cylinder?


Oh wait, I think you mean the freeplay before the clutch disengages? Someone with a manual can confirm.