Bleeding Clutch

[Shaun]

And I could use stronger words than bleeding
Ok so testing the clutch and brake lines before they are covered up, using a new Sealey (so decent quality) vacuum bleeder, not used it before but is seems simple enough....
Have fitted the rubber cap over the nipple and secured with a cable tie, it draws fluid fine but the bubbles never go. I have firm clutch pressure and the clutch as far as I can tell (its not easy pushing the pedal and trying to see the slave cylinder!!) moves 10mm to 15mm.
I would think no air leaks in the line, I have two bulkheads connectors and one inline, if there was a leak I would assume after a few pedal depressions the fluid would ooze out, the vacuum it generates is not all that hard.
Thoughts anyone? Or is it back to the old two man job and damn the new fangled tech
Cheers

 

[Neil]

Shaun, I've experienced the same thing using a little hand vacuum pump- the fine bubbles never quit coming. I've concluded that it is from air leakage around the threads of the bleeder screw when it is loosened. I'll try putting some Teflon tape on the threads the next time I bleed the clutch or brake and see if that solves the bubble problem.

 

[Shaun]

Hi Neil, that makes sense, I guess unlike the old fashioned way this is pulling the fluid so would draw air in as much as pull the fluid. Those bleed nipples always seem pretty rubbish quality with a coarse thread, I will pop mine out and PTFE the thread see if that helps. The pedal is firm and I assume that's about the right amount of cylinder travel
Cheers

 

[DJ]

.You wont get rid of tiny bubbles(Don Ho couldn't either). If your pedal is firm your likely done. Did both my Lola clutch and front brakes on my F150 this weekend.Tiny bubbles with great pedal . Doesn't matter what kind of thread you have you wont beat the vacuum . If you have air in system when you start you may see big bubbles.Thats air from inside that you want to eliminate.

 

[mark b.]

I've switched my hyd clutches over to the Earl's speed bleeders. Makes it easy peazy.

 

[Shaun]

Not seen those before, watched a YouTube they seem pretty cool. I did though find out a good wind of PTFE tape did the trick and no bubbles appeared in the pipe using the vacuum tool. Brakes next!!

 

[Cliff Beer]

You can always use a pressure bleeder instead of a vacuum. If indeed the small bubbles are from air being drawn in past the threads of the bleed nipple under vacuum, use of the pressure bleeder can confirm this (or not).

 

[Shaun]

Hi Cliff
Yes since looked at that, started on the front brakes which seemed to self bleed, mind you I had left one hose finger tight so did have a leak!! Found that connecting a clear hose to the bleed nipple and holding it upright and cracking the nut open the bubbles cleared out quite quickly, had to stop there for the night but did both fronts and they seem good

 

[Jim Cowden]

Put Plasticine or a putty around the base off the thread on the cyl just to stop it sucking air down the tread if it bothers you.
When you are done just remove it.