Combines Hydro drives

The hydrostatic drive in gleaner and most other combines is a big hydraulic motor, but no variable flow valve. The hydro pump is variable output and reversible. the more you advance the speed lever, the more oil the hydro pump puts out and the faster the hydraulic motor turns. When you pull the speed lever back to neutral where the pump puts out no oil, the hydraulic motor stops. Pulling the speed lever back reverses the oil flow from the pump which makes the hydraulic motor turn the opposite direction to make the combine back up. They have an oil cooler to control oil temp. these hydro systems work at very high pressure, up to 6000psi

Yea, all that what rotor man said - but the hydro units have their own pumps - they don't get their oil from the hydraulic pump for the rest of the combine. I'm no mechanic by any means, but I've not seen a cooler for the hydro unit. The fan idea might work well - but I'm wondering why your hydro is getting so hot to start a fireIJ I've never seen much trash build-up on any of ours. It seems to me I heard once that choosing a gear that allows nearly full hydro will keep the unit cooler - say run in 2nd gear near full hydro instead of 3rd gear_part hydro. Clear as mud, huhIJ Maybe I should just stick to stupid remarks! Tom langan

Thank's for helping me explain how this thing works Tom. I did not explain myself very well.

I believe the main hydraulic pump on my R60 feeds the hydro pump. I will have to look at the machine or a hydraulic schematic to be sure but that is how I remember it. Tom Russell