losing power

Old 04-23-08, 06:14 AM
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losing power

I have a Ranch King lawn tractor 18.5 hp 46" about 7 yrs old. The tractor slowly loses power going uphill until it won't climb the hill. It seems to drive fine on level ground. replaced drive belt with same results. Also hear a slight whine near back of tractor when engaging hydrostatic drive. Any ideas what may be wrong and how to fix???
Old 04-23-08, 01:56 PM
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I'll bet that the "slight whine near back of tractor when engaging hydrostatic drive." is a leaking head gasket.Have you run a compression chek on the engine or checked these bolts for tightness? Reply back with engine model & type#'s off the engine shroud.
Old 04-23-08, 03:41 PM
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You may need to purge the transaxle (remove air from the system). With the tractor on level ground, pull the relief valve (the lever that you move/lock to push or tow the tractor).
Start it up, and gradually move the hydro control full forward, hold it there for several seconds and then gradually move it to full reverse. Hold it there for several seconds, and repeat this process 3 times.
Shut it down, return the relief valve to its normal operating position and then start & drive as normal. You may need to purge it again to remove any trapped air.
Old 04-23-08, 10:50 PM
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The whine sound from a hydro is often caused by air in the system. This could be because the fluid level is low. If so, fill and perform the purge procedure oldchevy4x4 mentioned.

Another thing to make note of is that there are cooling fins in the aluminum casting of the tranny on top, and a fan at the pulley. This fan must blow across these cooling fins to provide proper cooling of the unit and prevent cavitation. These fins often get clogged with grass clippings and debris, and then the unit overheats and cavitates, causing premature wear and loss of power....especially after it has warmed up.

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