Low main hyd pressure

onefarmer · Aug 3, 2018

I've been having trouble with the hyd on this thing. Flow was low as was pressure. Got the flow fixed. The gasket blew on the filter bypass valve so it was dumping back to sump. Anyway that's fixed but it only gets up to 1500psi. What could be wrong with that. I had a look at the trans pump last winter. It was in good shape. Took the front pump apart, inspected, cleaned, resealed. Still low pressure.

Any ideas to look at?

onefarmer · Aug 3, 2018

Oops it's a 4320. That might help.

Tx Jim · Aug 4, 2018

Have you tried turning stroke control valve(key 32) in to increase pressure? Where are you checking pressure? If checking at rear breakaway coupler pressure control valve(key 2 2nd photo) under hood could be blocking pressure to the rear of tractor.

onefarmer · Aug 4, 2018

I didn't try adjusting the stroke control yet. It looked just different enough from my 4430 I didn't want to mess with it until I researched some more. I did clean it when I had the pump out. Pump is a royal pain to get at on this tractor. I found it easier to take the fuel tank out and remove that plate. It's formed around the pump.

The under the cowl pressure control is the only thing I didn't take apar.t and clean. I wasn't sure if it controlled the high pressure or just fed low pressure to brakes and lube. Maybe it's next?

The brakes came apart several years ago and it hasn't been 100% since. After effects of having all those metal shavings in there

Low main hyd pressure

onefarmer

Well-known Member

onefarmer

Well-known Member

Tx Jim

Well-known Member

onefarmer

Well-known Member

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