# 8N Hydraulics Quit



## Snordy (3 mo ago)

I have a '51 8N. The lifts abruptly quit working. Opened the side panel and felt that the control arm was well seated in the control lever, so no easy fix there. Took off the top lid leaving enough oil to cover the control lever-and then some, turned on tractor and pried the control lever back and forth. Absolutely no oil came up through the oil tube port after just a few moments. Drained the oil and let it set overnight.

The next day I ensured that the PTO was active, and I may not have waited long enough to see oil coming up the oil tube the previous day: I repeated the test and waited a bit longer, and oil came up out of the oil tube port after pressing the intake control valve. It was slow however, and not a spray. It stopped when I released the valve. I did not wait longer to see if it would spray.

I didn't see turbulence from any leakage from the safety valve.

Any suggestions?. Do in need to get a whole rebuild kit for the pump ($$$), or can I troubleshoot it more to pinpoint a specific issue?


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## harry16 (Dec 8, 2011)

Good morning Snordy, welcome to the tractor forum.

You say that you "pried" the lift control lever back and forth? That's one problem. That handle should moved freely. What operates the "intake control valve". 

Sounds like Your pump is feeble at best. Time for a rebuild kit.


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## Snordy (3 mo ago)

I rebuilt the pump, but after reassembling it two anomalies were noted: 1. According to this video 



, time stamp 10:10 to 10:24, the outlet valve which is located in 4 places in the side chambers was placed over the smaller inlet valve spring WITH THE FLANGES FACING UP TO THE TOP. According to the diagram for the rebuilding of the hydraulic pump in FO-4 Ford Shop manual the flanges should be facing down. Instead I followed the guidance given in the FO-4 manual. In doing so, however; 2. When compressed air was pushed into the oil port at the base of the plate air leaked out of the exhaust control valve (or the bushing around it) while the control valve was in the neutral position. According to the video noted above, this should not have happened. I'm skeptical that this is an issue, however. Comments anyone?


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