hydraulic pump not working

[Plow Boy80]

I recently bought a 52 8n and the 3 point does not work. I have cleaned the pump and freed the control valves. They are moving the way my I&T manual said still not working. I have no pressure at the test port. Can anyone help me?

 

[old]

Do you have the PTO in gear and the clutch pedal up???? If the PTO is not spinning you got no hyds on the N series tractors

 

[souNdguy]

are you also chaining the 3pt lift arms down when you exercise the lift with the gauge plumbed in, and have you verified the relief valve is not stuck open?

soundguy

 

[Plow Boy80]

I have not chained the arms down they will not move at all. There is no oil coming from the relief valve. There is not even any oil at the test port. I have the pto on and clutch up.

 

[Plow Boy80]

Maybe inlet valves stuck closed?

 

[souNdguy]

i thought you said you already serviced the control valve?

if not.. time to do it. first, though.. piull a chamber plug and see if it is air locked. I've only ever heard of a few rare instances of them air locking though..

soundguy

 

[Plow Boy80]

I serviced the control valves but not the valves for the cylinders the ones in the valve chamber.

 

[souNdguy]

that's not the intake valve though.

I'd think even with some wear on the individual chamber valves that she wouild at least pump some when not under load.. etc..


soundguy

 

[Plow Boy80]

Tractor has sat for atleast 10 years and the control valves where frozen I was wondering if the same could be true for the other vales. the oil was like tar when I got it.

 

[TheOldHokie]

(quoted from post at 20:49:42 03/24/11) Maybe inlet valves stuck closed?

Judging from your description of the condition in whiich you received it most anything could be wrong - sticking intake, exhaust, and/or check valves are all possibilities. I'd say time to pull it out and clean and inspect it thoroughly.

TOH

 

[Hobo,NC]

Its possible,,, you missed the EZ part the valves come rite out,,, they are no more different than the valves in yer engine,,, look at the valve seats and the seat on the valve...

 

[souNdguy]

did you pull the chambers apart for inspection?

soundguy

 

[jackinok]

is your pto turning?if not you prbobably didnt get the shift lever installed correctly.pto shifter has a slot it must set into to engage.

 

[Plow Boy80]

pulled all the chamber valves this morn. all free and clean and all the passeges are seem to be open. Still no oil at test port. If it was air locked how would I salve that prob?

 

[JMOR]

(quoted from post at 12:11:12 03/25/11) pulled all the chamber valves this morn. all free and clean and all the passeges are seem to be open. Still no oil at test port. If it was air locked how would I salve that prob?

ave you looked thru the round inspection port on right side of tractor to be sure the scotch yoke elements of the pump are moving when tractor is running? You should at the least see them churning the fluid at center of pump housing. Just trying to establish basics here, such as pump is being mechanically driven, before going off on a chase.

 

[Plow Boy80]

Yes they are moving and oil is moving around them.

 

[JMOR]

(quoted from post at 14:18:05 03/25/11) Yes they are moving and oil is moving around them.

K, good.
Photo shows control arm with intake control valve in full lift position. Is yours in this position?

 

[jackinok]

have you tried moving small lever under seat?if in fact they get enough wear and slack in top cover linkages they wont work right.On my 52 when i bought it,arms would only go up and down in position control,I had no position control as far as setting a height but they would move.They would not move at all in draft control.Can you see control arm moving when you move lever?

 

[Plow Boy80]

Yes the control arm goes in that possion. I adjusted this this morn. the way my I&T manual said.

 

[JMOR]

OK, with the intake control valve in that position, you should have opened the suction side of the pump to sump oil. I say should have, because the hole that the intake control valve uncovers in its bushing is relatively small & there have been numerous instances where this hole is clogged. Sometimes requiring removal of the bushing in order to clear the trash under it & in the passage to the inlet valves of the 4 cylinders. Look at drawing & you can see path from intake control valve, to inlet valve at cylinders, to piston, out the outlet valves to check valve & on to a properly closed overpressure valve , to test port, vertical tube, to lift cylinder.

You could temporarily bypass the intake control valve by removing the plug marked "IN" & allowing suction/intake from this point. Just to see if it will pump. This would remove concern about a blockage around intake control valve & its bushing.

 

[Plow Boy80]

problem fixed! It must have been air locked I took the 1/4 in. plugs out and it started pumping 3 point and contrals seem to be working fine

Thanks to every one.

Plow Boy80

 

[JMOR]

(quoted from post at 16:08:50 03/25/11) problem fixed! It must have been air locked I took the 1/4 in. plugs out and it started pumping 3 point and contrals seem to be working fine

Thanks to every one.

Plow Boy80

ood deal!

 

[souNdguy]

IF it was an air lock, removing a top chamber plug while it was running would do it. but I've only rarely heard of them air locking.. and you have to be carefull working on moving parts..

soudnguy

 

[Plow Boy80]

thanks Soundguy I fixed it this afternoon by removing the 1/4 in. plugs and leting it pump through there. It must have been air locked like you said.

Thankyou for your help

Plow Boy80

 

[souNdguy]

good to hear. it's rare.. but as you saw.. can happen. glad removing the plugs got er for ya.

soundguy

 

[JMOR]

(quoted from post at 16:08:50 03/25/11) problem fixed! It must have been air locked I took the 1/4 in. plugs out and it started pumping 3 point and contrals seem to be working fine

Thanks to every one.

Plow Boy80

o, what did you remove?? Upper or lower? Both upper & lower? All four? :?:

 

[Plow Boy80]

I removed all four plugs and let oil flow though for a min.

 

[JMOR]

(quoted from post at 21:06:48 03/25/11) I removed all four plugs and let oil flow though for a min.

hat ought to cover all the bases from air lock to intake obstruction....glad I suggested it & you expanded it.