Clutch issue

How many miles are on the unit? You indicated that you were in 5th gear and then the truck stopped pulling. Did the engine speed up, like the transmission had been knocked out of gear, or did the whole truck start to lose road speed? Lets start with that. And do you still have reverse?

I thought about this some more . . . and to me it isn't likely that the transmission has just failed catastrophically. What I am going to suggest is that you rebleed the master at the slave in the chances that you somehow still have a little bit of air and it isn't pushing the fork in all of the way. If that is happening the clutch will be dragging the transmission input shaft, preventing shifting. Use DOT#3, that is what the truck was designed to operate with. There is also a push rod under the dash that goes into the master that is a PIA to adjust, but you can lengthen the push rod to get more travel at the fork. Hope this gets you pointed in a good direction. Did you buy the replacement master at an auto parts store? Chances are, if you had gotten it at the dealer, the pushrod step wouldn't be necessary, but Chinese parts have to be different to avoid lawsuits.

I used DOT 3. The fl;uid was completely replaced but it is possible I didn't get all the air out of the system but it seeming to be clear. It was difficult keeping the hose attached to the valve but it seemed like there wasn't any air coming out at the end. I got the master and slave at an auto parts store. Both are LUK brand. I will see what I can do with adjusting the pushrod.

Thanks for your ideas, much appreciated

I forgot the other questions. The truck has 310000km so just under 200000 miles. The issue stated while driving in 5th. I was on the highway and all of a sudden the truck started slowing down and when I pushed on the gas it just revved up but still kept slowing down. When I tried reverse it was the same, just revved but did not engage.

I might be going out on a limb here but I think you may have installed the clutch disk backwards and the problem took 6 months to show up because the disk has worn down enough to cause the disk to start making contact with the flywheel bolts. That would explain some of the noises you've mentioned. Your engine reving up while you had it in 5th means the clutch friction plate isn't being pinched by the flywheel and cover. The high hat with the springs goes inside against the cover side and the mistake is easy to make. If the disk is locking against the flywheel bolts it becomes almost impossible to shift between gears.

One other thing. If you had the flywheel off to have it machined, did you make sure to use sealant on the bolts that hold the flywheel on when you put it together? The holes go through the crankshaft and into the block and oil will wick out onto the flywheel and soak the disk with oil making it slip. At least these trucks are easy to work on, right?

Here is something else to consider, and maybe this will be the answer to what is happening here. From your posts it isn't really clear whether you are still dealing with the same issues that a low pedal or low pressure would cause. Now is seems that the opposite is the case, like maybe pressure is keeping the clutch disengaged. You can put the transmission into different gears but all the engine does is rev higher when you push the gas, is that correct? I know Cusser mentioned it in another post and I am also going to suggest that maybe the rubber lines that connect the master and slave to the steel lines have gone bad internally, swelling shut. That would allow you to pressurize the fork, but then the pressure would be trapped, keeping the fork pushing the pressure plate and freewheeling the disk. You can test for this by stepping on the clutch pedal 3 or 4 times and then climbing under the truck with your bleeding wrench and cracking the bleeder. If a lot of fluid comes out under pressure and the fork moves at all you have found your culprit. The lines go bad and I have no idea how old they are on you truck.

just to clarify. The engine only revved in 5th and reverse. All the other gears was different in that gradually one by one started to make loud crunching/grinding noise while driving until I had no gears at all.

Based on what you are saying the input shaft is continuing to turn when it should be stationary. But then you would have trouble putting the truck into any gear, especially reverse, because there is no syncro on that gear. The input shaft is gears directly to the countershaft and that rotates independently of the output shaft which carries the 1-2, 3-4 and 5th gear. 4th goes directly from the input shaft to the output shft, bypassing the countershaft Reverse ties into both with am idler, forcing the output shaft to rotate backwards and it should be the one that isn't going into gear at all. The crunching noise is an attempt by the various synchronizers on the various gears to match engine speed / input shaft speed / countershaft speed to the different gears on the output shaft and the grinding is because the input shaft is spinning. Is there a chance that you didn't replace the pilot bushing when you changed the clutch? It gets installed in the tailshaft of the crankshaft. Maybe you got a bad master cylinder and it has failed but is sounds like you have a failure to obtain enough fluid pressure at the fork to disengage the clutch. Here is a link to basic transmission operation, and there is another one that follows it which talks about haw a clutch works. My thoughts on this is now that you somehow aren't getting the input shaft to stop spinning.
https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&cad=rja&uact=8&ved=0ahUKEwjHpKis2azSAhUB5WMKHWJDD6YQtwIIIjAB&url=https%3A%2F%2Fwww.youtube.com%2Fwatch%3Fv%3DwCu9W9xNwtI&usg=AFQjCNGeFiNSOKGZm7ivJ_f2Y0vJcwAQeQ&bvm=bv.148073327,d.eWE

I definitely replaced the pilot bearing. I also put locktite on the flywheel bolts. I guess I am going to have to remove everything to see what is going on inside. At this point I am not sure when I will be able to do that since I will be doing it outside and the weather is still not great here for doing that type of thing. Thanks foe all your information.