hydraulic help

[Agage1 83]

hey guys i finally found a c160 with hydraulics. i actually got 2 for the price of one. the one appears to be in good all around shape except the block is cracked so i got as a parts tractor. the other one's block was intact but it wasnt running so i got a good deal on the two. after rebuilding the carb, starter, new fuel lines, and a new battery i got it running pretty good. on my first ride when i went to try out the hydraulics my leg got soaked with fluid. one of the lines had a hole in it so i swapped it out with one from the parts tractor. after swapping out lines the hydraulics still dont work. i spent the whole day trying different combinations of parts between the 2 tractors but i still can't get it to work. this is my first hydraulic tractor so i know next to nothing on the subject so i'm sure there is something simple that i'm missing. any suggestions would be appreciated seeing that i dont even know where to start troubleshooting. i bought the ttractor solely for the hydraulic lift so i really want to get it going so i can hook up some attatchments and put it to work

[JamesBe1 80]

Hi Agage1.

Can you tell us what hose you had to replace? Does the tractor move under its own power?

The pressure for the hydraulics comes from the hydro pump (I think the charge pump). If it is a problem with hydro pump, then the tractor likely won't move. If it does move, then the problem is likely with your cylinder valve or lines.

Also, what kind of sounds does it make when you move the valve? Does the cylinder try to move in the least?

[Agage1 83]

Tractor moves fine. I can't tell if the pump makes any sound or not, I havnt welded an exhaust yet so the tractor is loud. I tried two different pumps and neither worked. But when a activated the pump for the first time fluid shot out from the hole in the line. This leads me to believe that the pump works or is my thinking wrong? When the pump wasn't activated no fluid came from the hole in the line. I have since replaced the line.

[Agage1 83]

With a little help from me pulling it the cylinder does move a little, but by itself it doesn't move.

[JamesBe1 80]

I have to assume that you have moved the valve handle back and forth several times to remove any trapped air.

Either your pump is not producing enough pressure, or the pressure is not getting to the cylinder to move it. I have a hunch that the problem may be with your spool valve.

I think the first step would be to verify proper pressure.

I am no expert, but I do have a D-180 and have dealt with the hydro system. There are several great people here that can give you more/better troubleshooting advice than I. Just keep bumping the thread till it attracts their attention

Also, there may be a sunstrand hyrdo troubleshooting guide in the files section that will explain the operation of the system. If it is not there, let me know and I will email you a copy.

Don't worry, we'll figure it out eventually.

james

[Agage1 83]

Hey thanks James I'll keep tinkering with it. I looked in the files section ealier but couldn't find anything on troubleshooting. I did work the lever to purge any air. Did I mention I tried 2 different pumps

[JamesBe1 80]

I've repeatedly been told (and rightly so), that replacing the pump with another used one is not a guarantee of a good pump. However, it sounds like your pump is good since the tractor is able to move under it's own power. Other than the pump, there's not a lot that can go wrong. It's either the spool valve, or the cylinder. Spool valves are a little more complicated than the cylinders, and hence, have a greater chance of being the problem here.

Dunno how mechanically capable you are, but my next step would be to disassemble the spool valve and clean it thoroughly. It's not that bad, just messy. If you do so, then remember to keep everything scrupulously clean.

Also, if you look around some of the yahoo groups, there are some manuals by toro that go into more detail about their hydro systems. Also, there are a couple of great threads around here that go into some greater detail about them.

[Agage1 83]

I took the pump apart and you re right doesn't look like a lot can go wrong. It was clean on the inside and the o ring was in good shape. Don't really know what else to look for

[JamesBe1 80]

Actually, there is a lot that can go wrong inside of the pump. The pistons ride on slippers that slide around the swash plate. Often, they get worn. Also, there is a pressure plate with slots cut into it. That often gets worn and starts leaking, but some members here have had success with lapping it back to a smooth surface to restore it's performance. There are some ball and spring check valves that can stick, and some very tiny passages that can clog.

Here is a great thread on hydro systems:

Also, read this thread on hyrdo pump rebuilding:

I suspect that the problem is with your spool valve. If you though that the pump was easy, the spool valve is even easier. After that, the only thing that can go wrong would be the cylinder itself. Some of the cylinders are manufactured to be rebuilt, and some have to be cut apart and rewelded back together. Hopefully, yours is one of the former.

Good luck, post some pick of your progress. They are worth a thousand words.

[Trouty56 565]

[JamesBe1 80]

And Bob to the rescue!

Thanx Bob.

[Agage1 83]

Thanks guys i'm gonna start reading up tonight.

[Trouty56 565]

Haha. James you are funny. I uploaded that file so I knew it was there....

sent via mobile....

[gd.pudge 2]

I'm not sure about your model but on the older hydro's there's a check valve inside the pressure line going to the valve. It's a spring on a tapered cone. If that spring is broken or missing the lift won't work properly