190xt hydraulic

Pulled my 190xt apart for an engine rebuild, actually my son did, got engine back together and everything is good there. The
problem is with the hydraulics. After the pump primes up it blows oil out the fill tube and also out the trans input seal. If it
were an engine I would say it has a blown head gasket. Air is getting pumped into the hydraulic tank and forces the oil out. The
system was completely drained because of water contamination. I have been over the complete system checking for leaks and making
sure everything is plumbed correctly. I think the moisture has caused a valve of some sort to bind up somewhere. To the point if
I had dynamite I would not have a 190. Any ideas what else to check. Holiday so dealer/tech support is closed.

The 180-185-190 systems were similar, but a little different. My memory is based on the 180-185. There's a little cast iron sump that bolts up to the bottom of the torque tube, that extends out beyond the torque tube on each side, enough for a pipe to enter/exit each end. The bigger tube is the pump supply, the smaller a return. There may be a screen laying across that casting. I think you can look, or feel, with some kind of probe, up through a pipe thread drain plug in the casting. If there, that screen may need to be removed and scrubbed to remove oil/water sludge.

How about hose connections on the suction tube? Have you been able to run it long enough to see if they're collapsing? What I'm getting at is this- if there is a restriction in free flow of oil to the pump, it can suck air in lots of places, where a leak may well not appear when it's sitting.

It sounds like you have catastrophic aeration of the oil. The pump must be doing it, and I think it could only do that if it couldn't get enough oil.

You mention the pump priming. So if it sits, does it act like it loses prime? I don't recall that ever being an issue with those tractors.

After it pumps the oil out is when the pump is repriming. I put new hydraulic hoses with new double clamps where the rubber parts are in the suction side. I have had the sump screen out and cleaned it as well. In the morning I will make sure I did not put the sump on backward, if its even possible. I don't know how that would make a difference, but I'm going to check anyway.

So much for my idea.

As I recall, the holes in the ends of that casting are different sizes, so incorrect installation is impossible.

Hopefully you can isolate/disconnect/bypass parts of the system to methodically figure it out, before resorting to dynamite.

The 180-185 didn't have any valving in the pump. The 200 did. But I don't remember on the 190. If so, have you checked that for sticking?

If there was no problem before, something was assembled wrong when putting it back together. If the suction/supply hose to the bottom of the hydraulic pump was removed, make sure the spring inside the hose is actually down inside the hose and not caught in between the hose and pump nipple causing air to be sucked thru it. If the screen at the hydraulic sump underneath the belly was removed, there is a chance it is a "directional" screen, meaning if it is installed bass-ackwards, it is aerating the oil. Some of those screens will work any which way, and some (I believe) must be installed so oil leaving the sump must be moving towards the engine or to the left. There is always a chance the suction/supply tube (which is pretty long) has a hole rubbed in it, but why now, and not before the tractor was worked on?

I pulled the screen completely out and it still blows oil out. The suction line has two pieces of rubber, one where you split the
tractor, and the other is a long piece I put in inside the frame just before the pump. Everything worked proper before the
overhaul. With the tractor running there is what seems low volume coming where the filter is, I took the filter off checking flow
at that point. There is a massive amount of air in the system.

In the 1960s when I last worked on 190XTs, they had problems just like you described. Some of the problems related to the screen as mentioned but the most trouble was caused by the rubber hose behind the frame leaking air into the system. Original hose clamps were part of the problem. Double clamps may help. Since it is the suction side, air can leak in but oil may not leak out. Anyway it is very hard on the pump gears and seals to run air in the system. Duey

The hose you refer to as the "split" hose isn't factory and was added by someone. Many have had this extra hose added just for clutch/engine work, so if it's a good hose (no pin holes) and the clamps are tight, should be no problem.

when i first started doing tractor work was at planters hardware in hopkinsville ky now been awhile but the seals in front of pump can go bad thinking there are two on input shaft one faces the pump one faces the engine you can get lot air in at that point now i believe that original there was only one seal but work order said to do a double off course i could be wrong but if you done everything else try that