750tlb Ford won't move when cold

Hey there I bought a 750 a year ago and has had this problem since I bought it
When I first start the machine and put it in gear the tires won't move so I lift the tires off the ground and leave it in gear rev to 1200 or so and let it run while I do something else, sometimes it engages within seconds and sometimes takes 5 minutes
Once running though it's a bulldozer on wheels but if I shut the machine of for a min tie it's like the torque looses all its oil and I have to wait for the rear tires to move again

Might be heat related. Does it have a filter to change?

it does it hot and cold and yes changed filter

Where is the filter that you changed? The parts diagram shows a filter internal to the charge pump and pressure regulator valve assembly inside the torque converter housing. That filter has a bypass that should open if the pressure gets high enough to overcome the spring. My guess would be that internal filter is so clogged that it's not allowing any fluid to pass, and the bypass is sticking closed when you shut it off and it takes some time for the pressure to build enough to get the bypass to open. Hopefully the charge pump doesn't need to be replaced (looks like it's not rebuild-able), as it costs around $2100.00.

When was the last time the fluid was changed, and how did the old fluid look? Also, I assume that you have but it never hurts to ask... Have you checked the fluid level?

Is the charge pump not right above the transmission with a cartridge filter on the back side of it? Accessible from inside the cab?
Also oil is all new as the hydraulic cooler ruptured and needed repaired

I'm not familiar with that particular model of tractor, I was just going by the parts diagrams, and from the parts drawings it's hard to tell. There is a dotted line that goes from the charge pump to inside the torque converter case which usually means that part goes inside there, but I just looked again and there's actually two dotted lines, one from the front of the charge pump going inside the front of the converter case and one from the rear of the pump going inside the rear of the case, so who knows what that actually means. In looking at it closer, it looks like the pump and pressure regulator valve are inside the torque converter case, but the rear of the assembly that has the filter inside sticks out the back of a bulge in the torque converter case so that the filter housing is actually behind the torque converter case and outside of the main transmission case.

Look at the parts drawing for the pump, pressure regulator valve and filter and you'll see the bypass disk and spring that I'm talking about, but if that's the filter that you already changed then my theory about the clogged filter and stuck bypass is already blown out of the water.

My next guess would be that the charge pump is losing prime and it takes some amount of time for it to build its pressure back up after a restart. Hopefully it's something as simple as the pickup tube is loose and the suction from the pump eventually sucks the tube in enough that it makes a good seal and starts sucking fluid instead of air. The pickup tube is inside the torque converter case and it goes from the sump in the bottom up to the front of that charge pump assembly. But to determine if the pickup tube is the culprit you would need to split the tractor between the engine and torque converter I would think.

Could the dump valve be partially stuck??

(quoted from post at 11:54:21 02/04/16) Could the dump valve be partially stuck??

Click to expand...

That's a possibility.

If it's not temp related, and might take a couple of seconds or 5 minutes to work, then it's something getting hung up and then it pops loose and you have drive. Service manual perusal time....

just strange as soon as I shut the machine off it looses its primer like a check valve or dump valve or something stuck partially open allowing to drain

I have not had one of these apart yet so was just wondering if someone has had a problem related to this who could tell me weather it was something internal or external