Need help bleeding clutch - The 1947 - Present Chevrolet & GMC Truck Message Board Network

retodd7711 · 08-08-2009, 06:30 AM

I'm still having problems with air in my clutch lines.
I replaced a faulty slave cylinder and just can't get it right.
I have "2-man" bled it a dozen times, and it works good for a while then gets "mushy"again.
I'm going to get a pressure bleeder today.
Could someone please walk me through step-by-step instructions for this.
I don't want to look stupid, but this has been giving me fits for a while now.
Do I leave the m/c cap on or off?
Should I bleed the brake system also?
(Dual m/c, no probs with brakes)
I truly feel like the girl on the right.....

retodd7711 · 08-08-2009, 06:32 AM

Oops, a little info for you.
'62 GMC
305 V-6
Four speed with granny
Clutch worked great before slave cylinder boot rotted out.
Thanks to all

PrerunnerRob · 08-08-2009, 10:04 AM

Are you losing any fluid? When you bleed it, are you making sure you don't suck any air back into the line when the pedal is released?

**Corts60** · 08-08-2009, 10:41 AM

retodd,

Have you replaced that flex hose for the clutch slave cylinder behind the engine? It is about 8" long I think and could be a good spot to be pulling in air. My truck is having the same issues, ie: bleeding down at a stop light. And that is after replacing both the m/c and s/c.

I'm about to pull mine this week and have a new one made up. Other than that, it is just like bleeding brakes. The best way to ensure you don't pull air back into the system is to fill a little water bottle or something half way with brake fluid, stick a hose on the bleed nipple and put the other end into the fluid and, make sure it doesn't come out of the fluid while bleeding. You should see air bubbles coming up in the fluid, if there is any.

Hope this helps.

markeb01 · 08-08-2009, 04:12 PM

One trick that has worked for me in the past is to block the clutch fork from moving with a 2x4, clamp or whatever works. That way you are applying full pressure against a solid object. Unlike bleeding brakes where the system is pressing against the drums or discs, if the clutch fork can move during bleeding, enough pressure may dissipate to allow some air to remain trapped in the system.

retodd7711 · 08-08-2009, 08:07 PM

All I could get was a vacuum pump.
I hooked it to the bleeder, filled the m/c and sucked all the nasty fluid out.
Then I poured in clean fluid,vacuumed, more fluid,vacuumed again.
The clutch seems to be grabbing solid now.
On to the next problem, before the slave went out the clutch grabbed about halfway, now it's grabbing near the top and I can't seem to adjust it back down.
If I go one way the clutch slips.
The contact point stays the same during this adjustment, always at the top.
The other way and it grinds trying to shift.
Truck only has 26,000 miles and it worked perfect before.
I just don't like a pedal grabbing at the top of it's swing.

08-08-2009, 06:30 AM	#1
retodd7711 chrome makes it go FASTER! Join Date: Feb 2007 Location: Cleveland Tennessee Posts: 2,884	Need help bleeding clutch I'm still having problems with air in my clutch lines. I replaced a faulty slave cylinder and just can't get it right. I have "2-man" bled it a dozen times, and it works good for a while then gets "mushy"again. I'm going to get a pressure bleeder today. Could someone please walk me through step-by-step instructions for this. I don't want to look stupid, but this has been giving me fits for a while now. Do I leave the m/c cap on or off? Should I bleed the brake system also? (Dual m/c, no probs with brakes) I truly feel like the girl on the right..... Attached Images __________________ She can't cook and she won't clean. But she looks good in a skirt and she brings me beer. She can stay for now. EDIT:: But she left me anyway, So forget her. 1962 GMC Stepside V6 4 speed My rolling resto thread http://67-72chevytrucks.com/vboard/s...d.php?t=324226 My old farm truck http://67-72chevytrucks.com/vboard/s...=1#post3465005

08-08-2009, 06:32 AM	#2
retodd7711 chrome makes it go FASTER! Join Date: Feb 2007 Location: Cleveland Tennessee Posts: 2,884	Re: Need help bleeding clutch Oops, a little info for you. '62 GMC 305 V-6 Four speed with granny Clutch worked great before slave cylinder boot rotted out. Thanks to all __________________ She can't cook and she won't clean. But she looks good in a skirt and she brings me beer. She can stay for now. EDIT:: But she left me anyway, So forget her. 1962 GMC Stepside V6 4 speed My rolling resto thread http://67-72chevytrucks.com/vboard/s...d.php?t=324226 My old farm truck http://67-72chevytrucks.com/vboard/s...=1#post3465005

08-08-2009, 10:04 AM	#3
PrerunnerRob Registered User Join Date: Jan 2007 Location: San Jose Posts: 847	Re: Need help bleeding clutch Are you losing any fluid? When you bleed it, are you making sure you don't suck any air back into the line when the pedal is released?

08-08-2009, 10:41 AM	#4
Corts60 Just here to tinker Join Date: Jun 2008 Location: Holland, MI Posts: 3,697	Re: Need help bleeding clutch retodd, Have you replaced that flex hose for the clutch slave cylinder behind the engine? It is about 8" long I think and could be a good spot to be pulling in air. My truck is having the same issues, ie: bleeding down at a stop light. And that is after replacing both the m/c and s/c. I'm about to pull mine this week and have a new one made up. Other than that, it is just like bleeding brakes. The best way to ensure you don't pull air back into the system is to fill a little water bottle or something half way with brake fluid, stick a hose on the bleed nipple and put the other end into the fluid and, make sure it doesn't come out of the fluid while bleeding. You should see air bubbles coming up in the fluid, if there is any. Hope this helps. __________________ 78 C10 SWB Diesel #1 (wrecked)http://67-72chevytrucks.com/vboard/s...1978+silverado 78 C10 SWB Diesel #2 (sold)http://67-72chevytrucks.com/vboard/s...d.php?t=650751 60 GMC Suburban (sold)http://67-72chevytrucks.com/vboard/s...d.php?t=445526 60 GMC 1000 (sold)http://67-72chevytrucks.com/vboard/showthread.php?t=298235 67 GMC 1500 (sold) http://67-72chevytrucks.com/vboard/s...d.php?t=803695 73 Chevy C20(Daily)http://67-72chevytrucks.com/vboard/s...d.php?t=852767 86 Suburban(summer unit) http://67-72chevytrucks.com/vboard/s...d.php?t=810697 88 Suburban 4x4(sold)

08-08-2009, 04:12 PM	#5
markeb01 Senior Enthusiast Join Date: Feb 2007 Location: Spokane Valley, WA Posts: 8,356	Re: Need help bleeding clutch One trick that has worked for me in the past is to block the clutch fork from moving with a 2x4, clamp or whatever works. That way you are applying full pressure against a solid object. Unlike bleeding brakes where the system is pressing against the drums or discs, if the clutch fork can move during bleeding, enough pressure may dissipate to allow some air to remain trapped in the system.

08-08-2009, 08:07 PM	#6
retodd7711 chrome makes it go FASTER! Join Date: Feb 2007 Location: Cleveland Tennessee Posts: 2,884	Re: Need help bleeding clutch All I could get was a vacuum pump. I hooked it to the bleeder, filled the m/c and sucked all the nasty fluid out. Then I poured in clean fluid,vacuumed, more fluid,vacuumed again. The clutch seems to be grabbing solid now. On to the next problem, before the slave went out the clutch grabbed about halfway, now it's grabbing near the top and I can't seem to adjust it back down. If I go one way the clutch slips. The contact point stays the same during this adjustment, always at the top. The other way and it grinds trying to shift. Truck only has 26,000 miles and it worked perfect before. I just don't like a pedal grabbing at the top of it's swing. __________________ She can't cook and she won't clean. But she looks good in a skirt and she brings me beer. She can stay for now. EDIT:: But she left me anyway, So forget her. 1962 GMC Stepside V6 4 speed My rolling resto thread http://67-72chevytrucks.com/vboard/s...d.php?t=324226 My old farm truck http://67-72chevytrucks.com/vboard/s...=1#post3465005 Last edited by retodd7711; 08-08-2009 at 08:09 PM.



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