4020 Wont lift 12' batwing mower

[Dane Bumsted]

I recently bought a 1965 4020, previous owner told me that he ran a 15 foot bat wing mower on it for years. I just bought a 12 foot bat wing yesterday to find out my tractor wouldn't fold it up. I can lift the middle deck up fine and one wing but the other wing just moves about 3 inches and wont go any further until i put a little pressure under it with my hand. I've never had any trouble with steering, braking or the 3 point.
 

[Tx Jim]

First thing to do if you haven't already is change hyd filter and clean sump screen, Then I'd suggest to check stand-by pressure which should be 2250-2350 psi.
 

[Dane Bumsted]

thank you for your reply, planning on changing the oil, filter and cleaning the screens friday.i was told that you can turn the pressure up on the pump?
 

[DONMYEIL]

Check standby pressure and check if that side may be binding due to rusty hinge. If the stand-by pressure is low chances are the stroke-control valve in the front pump is getting bad. Most of the time dirty filters just slow you down.
 

[430]

Could the cylinder on the mower be junk?
 

[retired farmer]

Swap your hyd. hoses and see if it raises it. If not, hyd. cylinder may be leaking internally.