Bleeding ZF-6 clutch hydraulics

[Sud]

I've tried searching for this but haven't really found any good concrete answer... other than just pump the pedal.

I have my tranny out of the truck, so I can do whatever is needed to get this bled completely and properly.

What is the correct way to bleed the clutch hydraulic system?

 

[05_LLY]

Pump it some...then pump it some more and then maybe a lil bit more, id say it all has to all be installed in the truck, pumping it with the slave (throw out bearing) hangin in the air with no force on it isnt gonna get it dun! good luck!

 

[durafrickenmax]

Only way to do it is pump, pump, pump. Drive it a few days and it will bleed itself.

 

[Bluemax]

There is a bleeder screw on the fender side of the master cylinder on the firewall if it still has air in it after pumping the holy hell out of it.

 

[Sud]

Bump...

Fixin to get into this stupid thing again, something gave in the clutch hydraulics, i'm guessin slave cylinder. lost clutch pedal resistance, and fluid dripping out of tranny bellhousing.

I've heard of people using vacuum pumps, or pushing against the slave cylinder by hand before re-installing the tranny... ??

 

[zf>allison]

Mine sucked for like three days pedal stuck to the floor alot. but it bled out just be patient. sucks something blew maybe your line fell off the slave? or the slave blew, did you install a new slave cylinder?

 

[Sud]

when i had the new clutch installed couple years ago, i let a buddy (mechanic) do it, and i thought the installed a new slave but not really sure, I was on a budget, maybe he didn't trying to save me a few bucks?

doesn't really matter at this point. lol. I'll be doing it this time, will KNOW it's a new one.

is it necessary to spend double the money for an "AC Delco" slave cylinder?

 

[zf>allison]

I bought a oem slave from napa I think it was $220. no problembs out of it yet, I couldn't tell you to go cheap on a part that's such a bitch to get to.

 

[dirty_max]

the slave from the dealer isnt that expensive is it?

 

[03spoolindmax]

If you can get access to a power bleeder I'd try that. If not than pump away

 

[Sud]

Rockauto has the Dorman brand slave for for a little under $100, and the AC Delco part for $200. I had Autozone transfer one in, they carry one for ~$90, with what i believe is a manufacturer name of "FTE".

So... is the AC Delco part any different? Is it any better? or are they all the same, same manufacturer?

 

[dirty_max]

you really shouldn't need to bleed it. the new slave will come pre-bled out and with the quick connect lines you shouldn't get much air in. the air should work itself out.

 

[Sud]

what makes you think it will come pre-bled?

I already looked/played with the one from Autozone - no fluid in it. has a plastic cap over the fitting hole, but you can compress it by hand, no fluid was expelled from the plastic fitting.

 

[dirty_max]

the factory gm one that i got was pre-bled. when i put it on the pedal was pretty good, not perfect, but pretty good. the more i drove it the better it got.

 

[Sud]

Did you purchase it through a dealership? AC Delco part or ?

don't reckon you have/remember the part number?

 

[RicknerLBZ]

I recently did a zf6 swap on my buddy's 05 and we put a southbend 650hp dual disk clutch in it with new factory slave cylinder have bled the clutch with vacuum and then by pumping but when idling and try to put in first or reverse does not act like clutch is fully disengaging like there is still air in it any thoughts?

 

[zf>allison]

Might be a leak in the system. But if you can pump it a bunch and it will go in its probably a little bit left to bleed.i pumped mine hundreds of times before it started feeling right. Sometimes a slow long pedal pump helps to. It was days before mine was normal.

 

[RicknerLBZ]

Ok I thought it was maybe sucking air but if it was doing that it should leak under pressure the master cylinder was out of parts truck but feels ok does not help to pump to get in gear but probably still has air has not been drove much yet may just need a little time

 

[clrussell]

Bump to the top hoping for suggestions on my new zf-6 truck. Bought it with bad dual mass flywheel. Clutch worked. Replaced with single disc valair and new slave. Flushed the master with new fluid by sticking the hose to the slave in a bucket and filling the master until I had only clean fluid.

I bled the master per instructions and pumped it about 1,000 times so far. Clutch will not disengage at all. I've tried the gm way of pulling a vacuum on the top of the master cyl and letting it sit for a while. Still no change.

Pedal feels good, just will not disengage the clutch..

Looking for ideas...

 

[zf>allison]

Pump it slow and fast