Toolcat 5600 has hydraulics but will not move

I have a 2018 TC 5600 (2,100 hours). I broke one of the hydraulic lines beside the right front wheel while moving snow in January. The line feeds the front equipment. The 5600 sat for about one month as we have another machine. We fixed the hose, re-topped the hydraulic oil and the 5600 was up & running again. About less than one machine hour later, it started to move slower and then would not go forward nor reversed but yet the front equipment goes up and down and so is the bed. The oil level is fine. I wonder if there is air in the system ? Is there is a bleeding procedure for hydraulics ? Help will be greatly appreciated.

More info on the problem. When the machine is cold, it will move somewhat forward/reverse but it feels something is slipping. When it gets warmer, I have to increase the throttle to get it to move. There is a weird sound coming from the front right. Eventually when the machine is a lot warmer, it will not move. The front cylinder still moves and so does the bed up and down, but the front tack appears to move slower than it did before.

The hydraulic system is self bleeding system. Do you have any codes?

no codes !

Do you have steering and is the hydraulic fan working?

I have steering, not sure about the hydraulic fan but I will check today.

That’s a story of the ages. A hydraulic line gets replaced, machine works for a short time, then it doesn’t. Is it a coinkydink? Or, does the narrative suggest a contaminated hydrostatic system? A little dirt or debris from the new hose, that went unnoticed. flushed right into the drive motor. It’s a timeless theme, causing heartbreak and despair. Draining a maintenance budget faster than a broken hose draining a hyd reservoir. Good luck and keep us posted.

A bit more info, I started the machine to get it off the trailer. It idled for about 10 mins and another fan kicked up in the rear. I supposed this is the one FW-Cowboy mentioned ?! Cold It does move but as the TC gets warmer it starts to kind of slip, then I increase the throttle and then it will move again. Eventually, full throttle and it will bearely move. It's like a relief valve is being opened.

More info. I changed the return and charge filters. Emptied the Hyd tank and filled with new HD-30 Oil. I opened the 2 filters, no debris. I backed it from the garage low-ilde and tried going forward and it moves slowly, somekind of slipping sound. I noticed when I release the gas pedal, the machine continues to move a little bit as opposed to before, it would stop immediately. If I increase the throttle, it moves more firmly but eventually the slipping catches up. Also attached is a picture of sightglass. The ball is higher than the coloured oil, wonder if water or condensation is in the system ?

I think your drive belt is slipping, there is a tensioner on it which is know to loose tension.