bx2660 hydraulic pump

[Haywire]

I've not looked. Is it integrated into the transmission? I assume it is.

Ian

[Haywire]

Interesting discussion. Technically, the BX has two hydraulic pumps. The Hydrostatic transmission pump and the primary hydraulic pump.
In the case of the BX series, there is one primary hydraulic pump that supplies all hydraulic fluid. This includes the fluid to keep the HST full. The primary hydraulic pump puts out about 5.5 Gal/min unloaded at full speed. The flow diverter maintains about 3.3 gal/min to power steering and HST at all times with the rest going to implements and 3ph. That's why at idle implements won't move. All flow is being diverted to power steering and HST.

The hydrostatic transmission pump and motor are a self contained unit. Meaning the HST pump sends fluid to the HST motor and it loops directly back to the HST pump. The HST pump does not draw fluid directly from the reservoir. Additionally the HST pump and motor do not dump fluid directly back to the reservoir in the transaxle. Small amounts of fluid that "leak" past the piston seals in the HST pump and motor flow back to the reservoir. This is by design. The primary pump supplies fluid to make up for this bypass as well as keeping positive pressure on both the input and output side of the HST pump in either forward or reverse. Without the primary pump, the HST would slowly drain all fluid and stop functioning correctly. The HST can not work without the primary pump.

Found this on a search.. I snipped some of the quote out in the interest of space. If this is correct, I assumed wrong.

I was thinking about rigging some kind of transmission oil cooler in line with the primary pump after the warranty expires, but since it appears the HST doesn't really draw from the reservoir full time like the primary pump does, a cool reservoir doesn't necessarily mean a cool HST. By 'in line' I was thinking of a priority valve diverting a couple gallons/min to a radiator/fan. I went from that to the possibility of putting a slightly larger pump on it so that diverting a couple gallons to a cooler wouldn't affect performance of steering and FEL.

An idle mind is a dangerous thing... LOL

Ian

[leonz]

Hello Ian,

If the hydraulic pump is up in the right
front under the injection pump the main
pump is separate from the transmission
charge pump.

I am unsure if it is a two section gear pump.

IF the 2660 is using the same transmission
as my fathers Wheel Horse 525 Hydro it is inside the
transmission and is an internal charge pump.

Most small tractors; scuts, cuts, etc., have internal
charge pumps in their transmissions.