8n lift only lifts at full throttle

Bigwade

Member
I’ve been plagued with issues on the hydraulics on this 8n. After 2 pump rebuilds it started having an issue that the lift is now so weak it won’t lift an empty boom pole unless it is full throttle. The quadrant adjustment is all the way to the rear. It has a new style piston in the top lid that was recently replaced. It is full of fluid and leaking out of the bottom side cover hole. I’ve only had an issue with this before with very heavy implements.
 
(quoted from post at 22:41:51 06/28/20) I ve been plagued with issues on the hydraulics on this 8n. After 2 pump rebuilds it started having an issue that the lift is now so weak it won t lift an empty boom pole unless it is full throttle. The quadrant adjustment is all the way to the rear. It has a new style piston in the top lid that was recently replaced. It is full of fluid and leaking out of the bottom side cover hole. I ve only had an issue with this before with very heavy implements.

Chain the lift down, connect a piece of tube to the test port and run it back into the transmission filler. Start the tractor and measure the rate of flow coming out the hose both at idle and WOT. My guess is its nowhere close to the roughly 2.8 GPM the pump is supposed to produce.

TOH
 
(quoted from post at 10:24:57 06/29/20) Is there any good place to get a fitting for the test
port?
ny decent hydraulics supply house. I made mine faster than I could drive to town or order one. A 1/2 X 20TPI bolt as I recall , drilled thru, brazed to a 1/4 inch NPT nipple.
ugberoo.jpg
 
Pulled the side cover and made it lift with the
throttle at full throttle, saw turbulence on one side.
On further inspection it seems the gasket on the
pto side pump chamber busted out and was
spraying fluid.
 
(quoted from post at 09:13:37 07/01/20) Pulled the side cover and made it lift with the
throttle at full throttle, saw turbulence on one side.
On further inspection it seems the gasket on the
pto side pump chamber busted out and was
spraying fluid.

You can put the side chamber gasket on backwards then it won't pump and you get to drop the pump again BTDT.
 

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