Brake/Clutch Bleed Question

[RJFabCab]

Hi to Loren, Tool Pants, and others... :)

I bled the brakes and clutch and thought of a couple of questions (Motive positive pressure technique).

1. When opening the caliper nipple valve to bleed, if you over loosen the nut, does this allow air entrainment? It seemed that over loosening the nut caused a somewhat constant stream of bubbles to enter the drain tube, but no brake fluid was leaking out around the nipple. Just bubbles in the tubing. How is this possible with the Motive positive pressure (15 psi) technique?

2. After bleeding the clutch, the clutch pedal was very slow to return to the normal position. I had to pull it up 5-6 times before the pedal would stay off the floor and pump it many more times before it would return to the normal position. Immediate feel was a bit "light". Sure enough, on the test drive, the actuation was not as smooth... it's a bit abrupt, like it needs to be rebled. So, does it matter if you pull up the clutch pedal and pump it to return it to its normal position while the Motive bleeder is hooked up and pressurized? I plan on rebleeding only the clutch...

Thanks for the help. Cheers

Edited July 15, 2004 by RJFabCab

[Loren]

1. The Motive should be at about 20 psi. Also, if the tubing on the outlet (bleed nipple) is not tight you might see some air bubbles move back after the valve is closed. When the valve is opened the flow should be one way (out) only.

2. If you follow my clutch bleed instructions then you should not get air trapped in the slave cylinder. Again you need about 20 psi at the motive bleeder. here are my instructions from the DIY:

1. Push the clutch pedal in by hand 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. Then carefully tighten the bleed screw. Wipe off the area and replace the rubber protective cap over the bleed screw. 

3. Remove the wood and the first thing you will notice is that the clutch pedal did not return... so carefully pull it up (slowly) to it's normal position. Try depressing it a few times (slowly). In a few cycles the feel should return.

[RJFabCab]

Thanks for the reply, Loren.

I've done full brake/clutch bleeding before and didn't have problems like this. Perhaps not having the Motive at 20 psi was the issue. I only used 15 psi this time.

I'll give it another go today with 20 psi.

Thanks