Just replaced slave cylinder and master cylinder in 89 F250 7.3L and I am having extreme difficulty bleeding the clutch. Been doing it for hours and no luck. Any advice?

 

I've bled two clutches recently. My f-250 I've had trouble with, but my F-150 I did a little differently and it bled 100% perfect in 1 shot.

My F-150 had absolutely no fluid, new master, new hyd line, new slave...everything.

Gravity bled it, and expected to need further bleeding but the gravity bleed was all I needed to do.

Get a rubber hose that will go over the bleeder and put it in a can of some sort to collect the fluid. Have someone keep the master topped off while you keep the bleeder open and let fluid drain out. Keep doing so for a few oz's of fluid. Close the bleeder and finish up. It should be bled after doing that. If not, you can follow the bleeding instructions from a Haynes manual, it's not like bleeding brakes.

 

Worked great. Thanks. What a relief because my poor legs feel like they were gonna fall off from all that pumping. Ha ha .

 

So the gravity bleed worked for you too eh?

I was trying to do the same thing you were with my F-250. It's still not even bled right because it still works and i havn't felt like fixing it. It's like half bled. I had to do my F-150 after that and just gravity bled it once and then was going to wait til the next day to finish bleeding by pumping it. Later on I happened to get in the truck and push the clutch and noticed it was perfect...so just gravity bleeding it worked perfectly fine and so far so good after about 1000 miles. Glad it worked for you too. I was so relieved when mine was perfect after 1 shot hah.

 

No way to do that with an external slave setup, is there?

 

Never done one of those before, but if ya gotta bleed those I don't see why ya couldn't gravity bleed it and hopefully it'll work out for you too.

 

There is no bleeder screw for this type. According to the manual, I am supposed to fill the slave cylinder off the vehicle while tilting it upward, and "rock" it back and forth to shake any air bubbles loose, while topping it off. Then I am supposed to fill the master cylinder with the line still disconnected from the slave cylinder and let it run out "untill the bubbles stop" and then put the cap on to prevent any more fluid leakage, hook up the lines, and then be good to go. Except I am not good to go. I am confident that I got all the air I could out, but I'm unsure as to whether it was enough. Or like I said in the other post that got moved to the trans and drive forum, perhaps my master cylinder is of too little displacement for the external slave cylinder.

 

There is a chance that the master is too small if you have the wrong one...

Honestly, I havn't worked with the external stuff, just the internal stuff, so I'm not the best one to guide you on that.

 

Ours has an external slave and we followed Mustangs gravity bleed advice and it worked. Give it a shot because we had tried the "instructions" and no way did it work.

 

I found the bleeder screw in the slave cylinder. I had no idea that the allen head setscrew was the bleeder. I thoroughly gravity bled the system, but it still didn't work, although the pedal was nice and firm. But I found out why. I posted this problem here, at FTE, the greatest Ford related forum in the universe, and I also posted it at Ford Six Performance, the second best Ford related forum in the universe, and was given some insight by Yakk, at FSP. He told me about a difference in the size of the bores for the external slave cylinder setup (0.875") and the internal slave cylinder setup (0.708"). This makes for a considerable difference in fluid displacement volume, thus, I couldn't release my clutch. If anyone is interested in doing an M5OD to T-18/T-19/NP 435 swap in a 1992 and up truck, order:

1992 Ford F-150 4.9L 4 Speed: WAGNER Part # F126886
W/4 Speed (T18 Trans.); 7/8" Bore {Clutch Master Cylinder}

1992 Ford F-150 4.9L 4 Speed: WAGNER Part # F103485
W/4 Speed (T18 Trans.); 1" Bore {Clutch Slave Cylinder}.

This setup will allow the use of the factory Clutch Pedal Position Switch. Just wanted to share the good news! Thanks for everyone's tips and suggestions, the truck runs great now!