D200 Hydraulic Help Needed

[Rideawaysenior 25]

Ok,

So after a few months of looking at it in disgust, I finally got back on the D200 and bolted up the re-rebuilt <---(long story) tranny. I filled it up with the 5 qts of 10w-30 and fired it up. Let it run for a few minuted to let the pump prime up. The problem is, there is no response from the tranny or either of the hydraulic lifts. I checked the PRV, I opened one of the ports on top of the pump too and the pump is shooting oil out so it has prime and is drafting from the tranny. After confirming that the pump has oil, I lef it run for about 20 minutes and noticed that the rear hydraulic motor was warming up too as it should, so this confirms that there is oil getting to the rear. Has anyone else ever had this problem? I was told that there is no need to burp these pumps either.

Does anyone know if the relief bypass that is located on the left rear wheel well could cause this problem if not working properly? I'm an average home garage mechanic, and can work around most problems. Hydraulics confuse me though.

Jack

[Jim_M 178]

Make sure the tow valve is closed.

[williambogner 0]

yea it might be stuck in the middle. make sure you turn it all the war right i believe tightly

[TT-(Moderator) 1,129]

The motor will warm up since the fluid is drawn and returned via the charge pump from the reservoir through the motor housing.

The hydraulic lift works off of the charge pump, so it should work as soon as the fluid is picked up and the air is worked out of the system. If the lift worked and the tractor didn't move, I would suggest cracking the caps at the acceleration valves at the motor, but you "have nothing" so there's no point in trying that.

Air in the system can cause many problems and can be tough to purge sometimes - especially on a divorced pump/motor system such as the D's use.

Exactly what part(s) of this was rebuilt or apart, Jack? :thumbs:

[Rideawaysenior 25]

TT,

THe pump is NOS, and the transmission motor was rebuilt but a local shop that had NOS parts still on the shelf for the motor. The tow valve is tightly closed. I'm guessing that the remote releif valve box on the left rear fender wouldn't be the culprit on this then. I appreciate the help.

Jack

[Rideawaysenior 25]

Ok, another update. The charge pump is wet, it's getting oil. I pulled the bearing cover off of the rear tranny motor, and when I fired up the engine, oil was pouring out under pressure as it should. I changed the pressure relief valve that is remotley connected to the tranny motor via two flex pressure hydraulic hoses. WHen I pulled the hoses, the hose to the left was wet, the hose to the right was dry. When I move the motion lever, the pump wines a little just like on my D160 but with no go on the transmission and no power to either of the lifts.

[TT-(Moderator) 1,129]

Can you reverse the two hoses on that remote valve, Jack?

I'm not sure what the function of it is, but maybe it only flows one way? :thumbs:

[Sarge 3,462]

I wonder if that relief valve is stuck or one of those hoses is collapsed inside ?

Sarge

[Jim_M 178]

That remote valve setup is there as a cushioning valve. It's a cross port relief valve. It's main purpose, as I was told, is to protect the transmission from hard reverse to forward (or vice versa) shifts. It's also there to keep the transmission from feeling jerky or launching too hard when you move the lever forward or backward.

The early D's didn't have it, it was added in the second or third year of production.

Your tractor will work without it if need be. You could try adjusting the valve. Just make sure you turn it only about 1/4 turn at a

time, they're pretty sensitive if they're working right. If you go more than one full turn and don't see a difference, put it back where it was, it's not the problem.

[Rideawaysenior 25]

Jim,

Any other thoughts, tried that nothing doing.

Jack

[Jim_M 178]

Which hose was wet? If it was the pressure side of the relief that was wet, then the oil is getting too it but you haven't built enough pressure to crack it open. That's not always a problem, since you haven't driven the tractor, it shouldn't have ever had to relieve any pressure.

I wonder if your charge pump is putting out enough pressure and volume. I don't have a transmission manual for a D series anymore, but hopefully someone here does.

There are ports on the pump body for pressure guages, the manual has the location of the test ports and the pressure and flow specs. You need a flow meter to check the volume. I would verify the pressure first though.