Hydro Stall

[clint]

Does anyone know what causes the "stall" in the hydro transmissions ? I wonder if it's some wear in the pump, or what, also has anyone fixed this problem. This of course is assuming that one has fixed all the mechanical linkages etc.

[Yosemite Sam]

The only times I have ever had one stall was because of extreme heat, low fluid, and I have one that had some moisture in it and it wouldn't move when first started when it was very cold out. Once it sat and ran for a few (10 or 15) minutes it took right off and ran great (these are narrow and wide frames).

Probably would get more responses if we knew what model you're talking about.

[67hydro]

Im not farmiliar with Stall,Are you saying it just quits moving,But everything seems to continue spin freely,engine ect.Or are you saying your pulling a load and it stalls the tractor,motor,ect??

I was pulling a drag with My #two 123 around the back and wanted to add more weight,I had 4 cinder blocks on the drag and a few rocks,Wasnt knocking down the weeds like I wanted,so I added 3 sections of rail road rail about 30-36 inches long,The tractor pulled it ok but i was having trouble with traction except in one section of the yard it would really hook up,in that section i stoped to move a couple peices of lumber,when I got back on the tractor I threw the lever forward to really take off,messing around,I didnt completly stall the tractor but it was letting me know it had a load and i had to ease off the lever!!

What about a blockage not allowing flow,is it maintained and cleaned out regular??Good filter?? good check relife valves,are they popin back up,or allowing bypass??

Good luck
Jason

[drysumpjet]

I have experienced hydrostatic "stall" in larger equipment resulting from low charge pump pressure.

If the fluid and filter are good, a test gauge reading the charge pressure as per the manual will help with troubleshooting. A significant drop in charge pressure when moving the hydrostatic control usually means an internal hydrostatic leak. Note charge pressure spec is different if yours has hydraulic lift.

[clint]

I posted this in reply to another thread, I'm not sure if that thread was deleted while I was posting or what ? Anyway the OP said when going up hills his hydro would tall, and he would have to adjust the lever, I was posting in reply to the thread if anyone knew the reason causing the need for adjustment from a normal ground speed to a complete stall while going up hills assuming all mechanical linkages, and the fluid was the correct level. I have a 1450, and it does this to some extent with a slower ground speed, and a steep hill. Sorry my post/reply got lost or moved.

Clint

[Jim H.]

You normally have to adjust ground speed when traversing up grade with a hydro, same as a variable speed, to keep full power to the mower deck.
This lets the mower work to it's maximum preformance.

I see some think you push it all the way forward and it should run in Hi gear. although a true pump problem could exist.

Like mentioned above,moisture,sticking valves,low or wrong fluid, worn swash plates , etc.

[aagitch]

you may need to just replace the trunnion springs as those are what help compensate for going up or down inclines. But even with good springs, you'll still have to adjust the hydro lever as least a little bit on a decent incline.