LUK problems

[Joejohn]

I have a new (been sitting for a long time installed) LUK clutch in my truck. I split the trans and engine and removed the clutch to make sure the pressure plate and disc were not stuck together. I installed a new clutch master cylinder and slave. The arm works fine and moves the clutch fork allot but now I’m stumped.

I push in the clutch and the fork moves just like it’s supposed to but the clutch does not release. I can’t get it into gear.

Now with that said my dad pushed me back by hand and I got the trans into gear as I was rolling and when I went to take it out of gear the clutch would not release. With the truck in gear and moving under its own power I was going up a hill with the clutch fully pushed in lol, then it slipped and I rolled back. I let out on the clutch thinking that it was released but no, it slipped and then finally grabbed and I was able to drive it onto a trailer. When I pushed the clutch back in it would not release and was stuck in gear. I yanked it out of gear before rolling over the front of the trailer.

What in the heck would cause it to act like this? I am stumped.

 

[hesutton]

Not enough travel of the rod on the slave cylinder because of:
-air trapped in the system, needs to be bled out.
-push rod on master too short, needs to be adjusted out (if equipped with adjustable rod)
-flexing of the firewall, need reinforcement plate

Heath

 

[Joejohn]

I purchase the adjustable rod and tried it. I had it adjusted almost all the way out and still nothing. It makes no sense. The clutch slave and the master are both brand new. Also I am 100% for sure there is no air in the line as I bled it over and over and over thinking that was the problem. Over 1 full bottle of fluid run through in the bleeding process thinking that was the problem. I know now for sure it is not. The top master was bottoming out the plunger and still nothing.

 

[topgunn]

I had similar problem. It could have a pocket of air , try removeing slave and rotate it while bleeding. I found the air is still above bleeder opening.

 

[jonathan]

I purchase the adjustable rod and tried it. I had it adjusted almost all the way out and still nothing. It makes no sense. The clutch slave and the master are both brand new. Also I am 100% for sure there is no air in the line as I bled it over and over and over thinking that was the problem. Over 1 full bottle of fluid run through in the bleeding process thinking that was the problem. I know now for sure it is not. The top master was bottoming out the plunger and still nothing.

just because you bought a new master and slave doest mean that they are bad. ive bought bad slaves and mc even though they were brand new

 

[Joejohn]

Is there a spec for how much the clutch fork needs to travel. I hate to pull the trans for nothing. I realize the new stuff could be bad but that arm is moving at least an inch maybe more.

 

[Cucamongan]

just because you bought a new master and slave doest mean that they are bad. ive bought bad slaves and mc even though they were brand new

X2 I hate IdiotZone and will not shadow their door unless its midnight and i need something absolutely positively at at midnight, and then its usually its just fluids.

now i pay a little more at NAPA, but get NAPA quality.

Good Luck on your clutch headaches!

 

[Joejohn]

I really dont know what to do. I hate to just start buying more parts and not change anything. It does feel very light on the clutch pedal to me.

 

[hesutton]

I'd take the master, hose, and slave all off as one unit and bench bleed it. Get someone to help you. Keep the slave higher than the master so any air will move up to the bleeder. If the pedal is that soft, I have to think you still have air in there and bleeding these on the truck (in my experience at least) is less than fruitful. Bench bleeding has always taken far less time and works much better. I've seen folks bleed hydraulic clutches all day (literally) to get the same result as 15 minutes of bench bleeding.

It's worth a shot and is better than pulling the tranny or buying new stuff first.

Heath

 

[Joejohn]

Thanks I'll give it a shot.

 

[kodiak98400]

My boy had this same problem on his 1st clutch job on a S10. He replaced slave and master cylinder and bleed at least a gallon thru the system. I finaly got tired of it in my shop and tore it apart . Turns out the pressure plate was not tight against the flywheel (about 1/8 inch gap ). Tighten everything up and put all back together and it worked great.

 

[RLDSL]

Since you have teh adjustable rod on there, it's pretty aparant that you have air in there, but, just to make sure, I'm going to play devils advocate and throw this out there just in case... when you replaced the clutch set, did you replace teh throwout bearing at the same time? if so did it come with a set as part of a matched kit of did you buy the parts individually ( i.e. is it possible that you have the incorrect throwout bearing on there causing far too great a distance of free play)?

 

[Agnem]

Here's the thing about clutch bleeding that I learned the hard way. The last time I went through this, it was at the Carlisle All-Truck Nationals, when the Night Moose showed up with no clutch after a failure coming off the turnpike. The hose had melted on the manifold. This was one of those "remember that conversation son, when we built your truck and I told you there were a few little things you needed to take care of ?" moments. Anyway, we got another hose from a local member (thanks Jarod!) and proceeded to try and fix it at the fairgrounds. We spent 2 hours and bled and bled and bled until we were blue in the face, and he still ended up driving it home, pretty much without a clutch. This all happened at night. The next day, I had the clutch bled in 5 minutes. Why? Because I could friggin' SEE! The new hose was one of the red translucent ones, and I spotted this huge air bubble right away! It was IN the hose, and would not move out! I took the hose, held it bent so the air bubble would float up to the top, pushed the slave in to force the fluid back up to the master, and walla. It was 100% perfect. Folks, there is no air in the slave. It's almost always in the hose! So get a red translucent hose if you can, and your life will be WAY better than if you have a black hose.

 

[subway]

might not be the recommended way but i have had luck getting air out by just driving the truck. i didint have a choice getting it home but the vibration worked all the bubbles out the top.

now granted i had the same problem where the manifold melted through so half of the line down and slave was fine. i could walk back to the shop though and put a splice in, add fluid and baby it home.

my pleasure helping a member out Mel, to bad i wasent closer for you. dont know if i mentioned but i found the second set up i had about 1 minute after you left.

 

[Dieselcrawler]

Here's the thing about clutch bleeding that I learned the hard way. The last time I went through this, it was at the Carlisle All-Truck Nationals, when the Night Moose showed up with no clutch after a failure coming off the turnpike. The hose had melted on the manifold. This was one of those "remember that conversation son, when we built your truck and I told you there were a few little things you needed to take care of ?" moments. Anyway, we got another hose from a local member (thanks Jarod!) and proceeded to try and fix it at the fairgrounds. We spent 2 hours and bled and bled and bled until we were blue in the face, and he still ended up driving it home, pretty much without a clutch. This all happened at night. The next day, I had the clutch bled in 5 minutes. Why? Because I could friggin' SEE! The new hose was one of the red translucent ones, and I spotted this huge air bubble right away! It was IN the hose, and would not move out! I took the hose, held it bent so the air bubble would float up to the top, pushed the slave in to force the fluid back up to the master, and walla. It was 100% perfect. Folks, there is no air in the slave. It's almost always in the hose! So get a red translucent hose if you can, and your life will be WAY better than if you have a black hose.

that was an interesting night. lol