Question on Clutch Bleeding Procedure

I've read the multiple post on clutch bleeding including the REnntech DIY. As stated: 1. Push the clutch pedal in by hand (very slowly) and use a long piece of wood to hold the pedal down. I wedged the other end (of the wood) between the seat and door frame -- with plenty of soft padding to avoid scratches. A second option is to have a 2nd person sit in the car and keep the clutch pedal FULLY depressed. 2. Open the clutch bleeder valve until clear, bubble free brake fluid emerges (at least 30 seconds according to Porsche). Remove the wood. 3. Then, pump the pedal again very slowly by hand for a further 60 seconds. After pressing the pedal down fully about 10 to 15 times, leave the pedal in its normal position. After allowing a fill time of 90 seconds, check that no more air bubbles appear at the bleeder valve (use a collecting bottle with a transparent hose). 4. Then close the bleeder valve. Wipe off the area and replace the rubber protective cap over the bleed screw. My question is in Step #3 it doesn't say to close the bleed valve while pumping the pedal. Is this correct? Wouldn't this pull air back into the line? Thanks for the clarification. Keith

first off...are you using a power/vacuum bleeder or doing it manually?

Sorry, I forgot to mention I have the Motive Pressure Bleeder. Keith

I had the same questions when I bled my brakes and clutch. Here is the exchange between Loren and I. You are supposed to leave the clutch bleed valve open throughout. NOTE: I didn't know it at the time, but the pressure gauge on my Motive was busted, so I may have overpressured the system and inadvertently wasted a lot of brake fluid that way. ME: Hi Loren I have a clutch bleeding question. I followed your directions: # Push the clutch pedal in by hand (very slowly) and use a long piece of wood to hold the pedal down. I wedged the other end (of the wood) between the seat and door frame -- with plenty of soft padding to avoid scratches. A second option is to have a 2nd person sit in the car and keep the clutch pedal FULLY depressed. # Open the clutch bleeder valve until clear, bubble free brake fluid emerges (at least 30 seconds according to Porsche). Remove the wood. Then, pump the pedal again very slowly by hand for a further 60 seconds. After pressing the pedal down fully about 10 to 15 times, leave the pedal in its normal position. After allowing a fill time of 90 seconds, check that no more air bubbles appear at the bleeder valve (use a collecting bottle with a transparent hose). Then close the bleeder valve. Wipe off the area and replace the rubber protective cap over the bleed screw. # You may notice that the clutch pedal does not return... so carefully pull it up (slowly) to it's normal position. Then depress it (slowly) a few (at least 5) times. In a few cycles the feel should return. If I follow the directions literally, and it seems like I am opening the clutch bleed valve at the beginning and just leaving it open while the fluid is draining and draining for about 3-5 minutes. It drains a lot of new brake fluid, almost a liter during that time. Am I doing it wrong? Thanks. LOREN: No, sounds like you are doing it correctly. That is the new "official" Porsche procedure. Seems like they are using the pedal to help clear any trapped air (to me). If you don't like that the old method was to leave the pedal depresed until all bleeding was done and the valve was closed. The trick to this method is to pull the pedal up very slowly - if you pull it up too fast you could pull air past the seals. ME: Thanks Loren, you're the best. I actually ended up doing it both ways because I didn't know if I was doing it the correctly the first time. Both times I needed to cycle the clutch about 20-30 times to get rid of that stiff jerky action. I burned through 2 liters of fluid. How much do I need to open the clutch bleeder valve if I do it the official Porsche way? If I let it drip, it's OK, but if I allow a steady trickle, unless I have a full liter on hand I end up running out of fluid in the master cylinder. LOREN: That will depend on the presssure in your power bleeder. I would guess just a few cc.

Quotes source post: 4778312

Yeah, pumping is only necessary if you're not using a power/vacuum bleeder.

Isn't it the case that if you use a pressure bleeder, it won't work at all if the pedal is depressed, because the master cyl piston will close off the intake port, blocking off any fluid flow form the reservoir? Bill

Great just when I thought I had the answer and was good to go with this weekend's project? The RENNTECH DIY for Brake/clutch bleed is using a pressure bleeder as described in Step #5 Fill the master cylinder reservoir with new fluid. Put the rest in the power bleeder. Screw the cap that came with the power bleeder onto the master cylinder reservoir. Put the pressure cap with the pump handle on the power bleeder and pump it up to just under 20 psi - do not go over 20 psi! Anyone else want to weigh in with an informed opinion Anyone else want to weigh in with informed decision?

It works both ways (as I was quoted above) described above. The Porsche way or the "old" way. I have done both and both methods work.

I did my clutch w/ the power bleeder. very simple. Hook up bleeder, pump to 15-20 psi, open clutch bleed valve (once I found it and removed rubber boot), open for 30 seconds, close. I was amazed how simple and actually did notice a difference in clutch operation. I wouldn't have believed I have, but I did.

TIP: Since you bleed a lot of fluid by following the "Porsche" clutch bleeding method, make sure your catch bottle is properly vented. Otherwise a fair amount of pressure will build up in the catch bottle and you'll get a nice surprise under the car when you pull the hose off the bleeder. DAMHIKT.