VAC hydraulic problem

I'm looking at a 1948 VAC that is for sale locally (SW Michigan). It seems to be in pretty good shape mechanically, even tho' it'd been used regularly in a local bluberry farm for the past 40 years.
Engine seemed tight, no bearing noise. Transmision was noisy, but this didn't seem from wear. it has a pto and a woods 42inch under-slung mower, which seems quite sharp. it's manually raised. The outer axle bearings were redone as well as the disc brakes. it has no headlights any longer and no hydraulilcs. I've been looking for a 'deal' to mow my 3 acres. At $1500, this set-up is almost right for me. The mower is a bit small, and the tricycle set up a bit unnerving to me, but it seems like one that will run for another 50 years without much maintenance. Tires are ok, no cracks, good tread. The paint is red, but it ain't originaly and there isn't any trace of decals left on the thing. Anyone have any thoughts? Thanks!

Move the hand lever to raise, the cam pushes the control valve by-pass closed and pump output is directed to the lift check valve passage and on to the piston to raise the draft arms.

Lever moved back to neutral, spring pushes control valve back to bypass, pump output circulates back to torque tube. Hitch piston is in a hydraulic lock, oil is trapped on the piston by the lift check valve and the release valve.

The after plunger is the release valve, It is pushed in by the cam when the lever is moved to the lower position, trapped oil is dumped into the return line to the torque tube, control valve is still in the bypass position.

Has nothing to do with changing the clutch. Your control valve is not fully opening to the by-pass position or the return is restricted after the control valve in the control head, return tube or the return filter in the torque tube.

If the control valve is stuck in the raise position (in), the release valve is not large enough to handle the full pump output, you will still have some pressure on the piston when you move the lever to the lower position.

Joe

Where is the hydraulic filter located? (as pertaining to one that might filter oil going to the 3 pt hitch).

I lost our manual about 6 years ago and my Dad keeps bugging the heck out of me me asking where the filter is, so I would really appreciate any guidance....

Thank you sincerely,

alex isaacs southern indiana

If that control valve is not all the way out in the by-pass position there will be some pump pressure on the piston. If you push in on the stem and and then let go, the plunger should pop right back out. There are 2 springs on that valve that push it back out to the by-pass position. Could be a broken spring, more likely the valve is just sticky.

When you put the valve actuator back on adjust tappet to valve stem lash to 0.010" on both valves.

Joe