Bleeding Clutch 944
Discussion
Just wondered if anyone has any gems of info that may help when bleeding a clutch on a 944 S2.
Situation is that I am finishing putting the car back together after replacing the clutch along with the slave, master cylinder and a few other bits.
I have been using an easi-bleed kit to force the fluid through and hopefully the air out of the system and although I've now got some resistance in the pedal, it doesn't quite feel right - like it still has air in the system.
There are various articles, some of which suggest getting the rear of the car higher than the front whilst bleeding the clutch - why will this work?
Any pointers appreciated,
Thanks, Phil
Situation is that I am finishing putting the car back together after replacing the clutch along with the slave, master cylinder and a few other bits.
I have been using an easi-bleed kit to force the fluid through and hopefully the air out of the system and although I've now got some resistance in the pedal, it doesn't quite feel right - like it still has air in the system.
There are various articles, some of which suggest getting the rear of the car higher than the front whilst bleeding the clutch - why will this work?
Any pointers appreciated,
Thanks, Phil
I don't know if it will be the same on your car, but I'll outline some of the discoveries that I made when I recently bled the clutch on my 87 911 Carrera.
1) The clutch system can blow quite a bit of fluid through in no time (compared with the brakes).
2) The hydraulic tank is the same for the clutch and brakes.
3) To protect the brakes from failing if the clutch develops a leak, the takeoff in the tank for the clutch is higher than for the brakes.
4) It is easy to get air into the clutch master cylinder because it moves lots of fluid, the height of the takeoff makes it look like there is still fluid there when actually the takeoff is drawing air.
5) Once you draw air into the master cylinder, the only way to let it out is to crack the nut on the master cylinder output pipe, and bleed the air there. Otherwise the pedal just drops to the floor.
6) Once the air is out of the master cylinder, bleed normally, but make sure there is enough fluid in the tank at all times. With mine you only have about 6mm height in the tank between the max mark and an uncovered clutch feed pipe.
7)Because the clutch moves quite a bit of fluid, it takes no time at all, but plenty of tank fillups, to push new fluid right through to the slave cylinder.
1) The clutch system can blow quite a bit of fluid through in no time (compared with the brakes).
2) The hydraulic tank is the same for the clutch and brakes.
3) To protect the brakes from failing if the clutch develops a leak, the takeoff in the tank for the clutch is higher than for the brakes.
4) It is easy to get air into the clutch master cylinder because it moves lots of fluid, the height of the takeoff makes it look like there is still fluid there when actually the takeoff is drawing air.
5) Once you draw air into the master cylinder, the only way to let it out is to crack the nut on the master cylinder output pipe, and bleed the air there. Otherwise the pedal just drops to the floor.
6) Once the air is out of the master cylinder, bleed normally, but make sure there is enough fluid in the tank at all times. With mine you only have about 6mm height in the tank between the max mark and an uncovered clutch feed pipe.
7)Because the clutch moves quite a bit of fluid, it takes no time at all, but plenty of tank fillups, to push new fluid right through to the slave cylinder.
Edited by dilbert on Monday 15th January 21:19
Edited by dilbert on Monday 15th January 21:21
dilbert said:
5) Once you draw air into the master cylinder, the only way to let it out is to crack the nut on the master cylinder output pipe, and bleed the air there. Otherwise the pedal just drops to the floor.
Ahh - I've seen this somewhere else and this makes sense. The RHD 944 has a separate reservoir for the clutch so there should be none of the other issues you mention. Like I say I have some pressure in the system so I have been able to depress the clutch enough to release the pressure from the friction plate - but it doesn't feel right.
Clarks-Garage is normally my bible - but given the difference in RHD vs LHD models I thought it worth asking if there were any tips!
softinthehead - if only life were that simple. Doing the clutch on a 944 is one of the rites of passage of 944 ownership. It's like being in the scouts and collecting your tent erecting badge - but with a few more grazes on your knuckles.
Phil
944pi said:
Doing the clutch on a 944 is one of the rites of passage of 944 ownership. It's like being in the scouts and collecting your tent erecting badge - but with a few more grazes on your knuckles.
Now come on chaps, that's just not fair. Last summer, someone posted on here that the mark of a true 944 enthusiast is having a spare DME relay in the glove box. So I bought one. Now you are saying that I have to do something a million times more complex and unpleasant involving hydraulic fluid and skinned knuckles ... definitely not fair to keep moving the goalposts! Oli.
zcacogp said:
944pi said:
Doing the clutch on a 944 is one of the rites of passage of 944 ownership. It's like being in the scouts and collecting your tent erecting badge - but with a few more grazes on your knuckles.
Now come on chaps, that's just not fair. Last summer, someone posted on here that the mark of a true 944 enthusiast is having a spare DME relay in the glove box. So I bought one. Now you are saying that I have to do something a million times more complex and unpleasant involving hydraulic fluid and skinned knuckles ... definitely not fair to keep moving the goalposts! Oli.
Sorry Oli. Didn't mean to imply that unless you scrabbled around for hours on end under your 944 that you weren't an enthusiast! In my case I knew that if I handed it over to my garage the costs of a basic clutch change would escalate out of control.
I look forward one day to being the 944 enthusiast with a DME relay in my glove box (I have one there already) and nothing else!
Phil
944pi said:
Sorry Oli. Didn't mean to imply that unless you scrabbled around for hours on end under your 944 that you weren't an enthusiast! In my case I knew that if I handed it over to my garage the costs of a basic clutch change would escalate out of control.
Ah, yes, good point. Handing the keys and a bundle of wonga over to someone else to fix just isn't the 944 way - I do agree. Perish the thought, if we had wanted to do that, we could have bought 911's, couldn't we! 944pi said:
I look forward one day to being the 944 enthusiast with a DME relay in my glove box (I have one there already) and nothing else!
You mean, a DME relay but no AVO meter, set of spare fuses, portable soldering iron, Gerber Multitool, small socket set, tin of WD40 and a torch? Nah - if I chucked all these out of the glovebox the missis would just fill it up with Carole King CD's! I know which I prefer ... Oli.
I bled my s2 clutch recently and it was not easy to get the pedal 'feel' right but eventually it was ok.
I had no choice but to have the front wheels on ramps and i dont think this was a problem,
tried with the ezi bleed connected without fluid just to pressurise system but this was no good.
removed slave nipple checked it was clear and used ezi bleed to blow system clean,
Finally got pedal back by pressurising system and pumping lots of times and used a lot of fluid.
very important to disconnect battery as starter cable contacts are close to slave nipple.
luckily my clutch plate was ok so i avoided having to replace it.....yet!
I had no choice but to have the front wheels on ramps and i dont think this was a problem,
tried with the ezi bleed connected without fluid just to pressurise system but this was no good.
removed slave nipple checked it was clear and used ezi bleed to blow system clean,
Finally got pedal back by pressurising system and pumping lots of times and used a lot of fluid.
very important to disconnect battery as starter cable contacts are close to slave nipple.
luckily my clutch plate was ok so i avoided having to replace it.....yet!
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