Engine/Transmission (1994 - 1998) Bleeding the slave

[BIG C]

Im having problems getting this dayum slave cylinder bled. I'm using a '99 F350 Clutch MC and line attached to a 1997 NV4500 slave cylinder with a NV5600 transmission. I searched and saw good things about the 97 5 speed slave. Well Im trying to bleed it and having problems. I filled the slave with fluid and attached the line. Then I pumped the slave about a million times trying to get the air out. After a few hours of pumping, filling, pumping, filling Im not sure what to try next. With the pedal all the way to the floor I can barely get it in 2nd,5th and 6th. No way can I get Reverse or 1st. It feels like the slave isnt fully disengaging the clutch because when I can get it in 2nd the clutch engages right off the floor. Sometimes if I cant get it in gear the truck will still go forward very slowly like it wants to go in gear but cant.



Some thoughts... ...

#1 Theres still air in the system some where. How do I get it???



#2 Does a NV4500 slave cylinder have enough throw to disenage a NV5600 clutch??



#3 I am trying to bleed the system while its in the truck. Is it neccessary to remove the whole system and bench bleed it?? Whats the correct way to bleed the system???



#4 Any other ideas??



Thanks

 

[B.G. Smith]

If the line enters the slave in the center on the horizontal, you may have to remove it to get all the air out. Either way you will have to unbolt it anyway so unbolt it, turn the line end up and push the pushrod all the way in. Have someone gently press the clutch a little to force a little fluid into the slave then repeat. Do that a couple of time and the air should all be gone. The reason the truck is trying to move is the synchronizer rings in the transmission are doing what they are supposed to do, keep the gears from engaging untill both are turning the same speed or both stopped which ever the case nmay be. Hope this helps. bg

 

[btanner]

I have heard of people using the nv4500 slave but I don't personally know if it works. I so personally know how to bleed the nv5600 slave which is quite a process. I wrote a pretty good write up about a year ago here it is



"That's not entirely true. First you can bleed the slave and master on the nv5600 it's just not very easy. First you take the slave unhook it from everything and then pull it out. Place it at a 45 and unhook the two plastic retainer tabs. The rod should come all the way out. Take off the fittings by punching out the retainers and then pull out the fitting be sure to keep trac of the little o-ring that comes out with the fitting. Then fill the slave with fluid until it starts overflowing. Then put a nail or something small into the end to break the surface area and re-fill. This should now have your slave bled. Forgot to mention that you'll want to take the clutch line (from the master to the slave) and place it up higher than the master resivior, so it won't leak. Next put fluid in the resivior and pump the clutch a couple of times until it is just fluid and no air. Next attach the slave to the clutch line. This is the most crucial part make sure that you keep the slave at a 45 so the fluid doesn't leak out and air get in. Then push the rod back into the slave and you should have some air bubbles come out the resivior and you are completely bled. Reconnect the retainer tabs and you should be done. It takes a lot longer than you would think but once you do it once it becomes a lot easier and it's a lot faster with someone helping. Getting that bugger back in is also not fun. But it's a lot cheaper than buying a whole new assembly.



You can tell if the slave is engaging by having someone push on the clutch while you are under the truck you can hear it going back and forth if it's working properly. You also can sort of see the assembly through the access hole on the bottom of the transmission and you can see the arm moving not a real accurate way of tell if it's working properly but better than nothing.



Hope that's the problem because it's a cheap fix just takes time. The bolts being loose would be nice because that's even easier and I could see it happenning if it's not tightened initially. Well best of luck on that"



The slave may not be exactly the same but it should give you a good idea on how to bleed it and hopefully it'll solve your problem. So yes I would bench bleed it but you only have to take off the slave to bench bleed. Hope that helps you some



-ben

 

[BIG C]

Yes I have been manually pumping the slave piston with the slave not installed. I havent tried pushing the clutch while doing this though. I will try that.



Yes everything seems to be working correctly except for the clutch hydraulics. The transmission shifts fine when the engine if off. When running the synchros spin up and with the clutch not releasing getting into gear is impossible. If only I could get the clutch to disengage.



Thanks for the help.

 

[btanner]

one other thing that I just thought of. If you replaced the transmission and haven't used it yet there is a slight possibility that when you installed the shifter that you put it on with the transmission being jammed between two gears. This happenned to me and it owuld go into certain gears but not first or reverse. Really angered me after all the time that I had put into it. The solution is pulling the shifter (four bolts) and using a screwdriver to pop the silver cup in the bottom back into the center. You'll know when it pops back in it becomes noticeably easier to move (with the screwdriver) Don't know if this even applies to you but I thought I would mention it because it was something that took me a long time to figure out.



-ben

 

[MLee]

Big C

This same question was asked awhile back. The solution was to hold the cylinder vertically under the vehicle [with the rest of the unit bolted in place] and work the rod in and out,[on the slave cylinder] this would in turn replace air with fluid. leave the fill cap ajare, or off. This method was used on a slave cylinder replacement, they told how to replace the slave and bleed it, when just the slave was replaced.

Have you checked out the difference between the rod length between the 5 and 6 speeds?

Marv.

 

[Island Dodge]

OK this probably wouldn't have anything to do with the CDTs, but it may, at least, be amusing. :-laf With the Mercedes this is how I do it. .

hook a clear hose from a front BRAKE slave to the clutch slave, open bleeders, pump brakes like crazy, (B/F and air goes UP through brake slave and master and up to resavour & out) close bleeders..... theres gota be a reason why this wouldn't do it but . . be easy, I,m a new guy

 

[Island Dodge]

" (B/F and air goes UP through brake slave and master and up to resavour & out) "



OOPS, ment to say... B/F goes up from the BRAKE slave, up through CLUTCH slave (via the hose), through the CLUTCH master and out the resavour, thaking the air with it.

 

[MLee]

" (B/F and air goes UP through brake slave and master and up to resavour & out) "



OOPS, ment to say... B/F goes up from the BRAKE slave, up through CLUTCH slave (via the hose), through the CLUTCH master and out the resavour, thaking the air with it.

Only thing, there is no bleeder on the slave. that is the problem. The parts houses have the slaves avaliable around 50 clams, but they can not tell you how to bleed the thing or- attach it to the hose, and make it usable. Thats why I bought the replacement when I was in Florida in April. No guess work.



Marv.

 

[DTangstrom]

I have never had good luck bleeding a slave. The best way that I have found is to fill the resevoir, leave the cap off, then walk away from it for the night. Has worked everytime for me, and I've tried vaccuum bleeders and the pumping method.

 

[Andy Redmond]

The NV4500 Slave works fine when the 5600 trans is retrofitted/converted to the older trucks (4500 as equipped oe).

 

[Island Dodge]

"no bleeder on the slave. "



I knew there was a reason it wouldn't work I did crawl under and have a peek at things but didn't notice the absence of a bleeder and I don't have my "real" shop manual yet. :{

 

[BIG C]

well I took the whole hydraulic system out of the truck and bench bled it. It is better and tyhe truck is driveable but it still feels like the clutch isnt releasing all the way when the clutch is pushed in.



I think my problem is the ford clutch MC is smaller than the NV4500 slave cylinder. Im guessing here but it looks like the ford MC dosnt push enough fluid to the slave to throw the arm all the way out. Its like the clutch MC is done pushing but the slave still has some room to go but nothing left to push it. I'm not sure if there is a solution for this other than getting a smaller slave?? Are the NV5600 slaves smaller than the NV4500 remans from NAPA??



Thanks!!