160 Allis

You cleaned the filter by the gear shifter ?  If so how dirty was it it may be pluged again.  

Mine will sometimes lose the prime on the pump. Then no hydraulic pressure.  Then no 3-point action, or very shaky 3-point lift. They used different pumps and lines between the standard, basic and One-Sixty vs. 160 tractors. You can go to www.Agcopartsbook.com , view books as guest, 160 model, Agco Allis brand, select 160 tractor. Look at the hydraulic Strainer & Lines section, page 148.  IF you have a compatible browser- sometime I get picture, sometimes not. They used to use SVG, now Silverlight for graphics, ahhh.
There is a strainer on the suction side, and a high pressure filter in the output side, on the radiator bulkhead.  If you replaced the pump with a good one, does it make pressure?
There is a port in the fitting on the top of the pump. I think it is meant for a high pressure test gage.  I started mine once with that plug out, and oil came shooting out 25 feet. I guess it makes pressure! This is very dangerous, so don't do it. High pressure oil can puncture your skin, then you die from infection. Or poke your eyes out. Just think worst imaginable from the Bible, worst imaginable.  At minimum you get a one gallon oil mess faster than you can shut down the tractor in an oil fogged,  slip-sliding unsafe panic.
If it doesn't make pressure there may be an air leak on the suction side. I count 6 potential places for air leaks: 3 o-riings, two hose clamps, and the cover for removing that strainer where the catch magnet is.  Mine has one of the 4 studs/acorn nuts on that cover missing, this may be my leakage problem, ya think?. However, if I keep the hydraulic level on the high side, I don't have a problem. It is an aluminum pump.  Other than this now rare problem, and 5 year batteries, this machine has never failed. 40 hp Perkins diesel, great fuel economy and an oversize cat 2 hitch. Not bad for a "French" tractor. A little noisy for me, I like mellow 4 cylinder gas sound at 1200rpm. I think AGCO has all manuals in stock.

So here is my question for anyone: Manual clearly says,  at two places, to "use Allis Chalmers Power Fluid 106"  in the hydraulic/transmission system and also in the power steering system. What is that ? I spent hours trying to find a cross reference to Power Fluid 106.  Maybe I can't Goggle that well, but it don't exist on the web as far as I am concerned. JD dealer guy couldn't find it in their printed book either. So I use universal tractor fluid.

Thanks Brian I will check it out and see what I come up with. I will keep you posted. 

I have a 160 that I had fits with the three point hitch, had sat for probably 15 years.  As soon as you started the engine the hitch went to the top, had to release hyd fluid from the system to get it back down.  Finally found the inside piston on the control under the seat was the problem.  When you look at the manual on that control there is an inner piston with little variation in the line spacing so it's hard to tell it's a seperate piston.  If you're still having problems that control would be a spot to check.

Check all connections on the suction side of the system.........that is where I found my similar problem to be.......specifically the 2 line clamps in the bell housing area. Good Luck, Eric NY