1600 Hydraulic/3 point issues

Hello. First time for posting, but I have read and checked this forum many times for some good info.
So here is the problem. I have a 1964 1600 diesel, wide front end, model #16-1210 Serial #148 019 607 no loader, and no remotes as of right now. The three point sinks down when the tractor is off with nothing hooked up, in a matter of 10/15 min. When I do have a implement {such as a 7ft brush hog} on it, the engine rpms have to be up around a 1000rpm to lift it and keep it raised. If you lower the throttle down the implement drops down. I bought the tractor a few months ago and have been working on it, on and off fixing multiple problems that I was aware of. Changed all the fluids and filters, fixed the brakes, etc. I finally had a chance to use it the other day for a longer period of time to do some brush hogging. After about an hour of cutting the three point stopped lifting the implement, it would try to pick it up but would not lift it. I shut down the tractor to check the hyd. oil level which was over full some. I had filled it to much when I changed the fluid. It was kind of white-ish/foaming on the dipstick some when I checked it. I disconnected the brush hog from the tractor and the three point went up. Also the bolt for the by pass is screwed in all the way. I then let the tractor sit for another hour or so and when I went to pull it in the shop and the steering was a lot harder to turn then it ever was before more so to the left then the right. But it is definitely a lot harder than it ever was before. The tractor steered very easy up until this point.
I am leaning towards a bad hyd. pump, I am going to borrow a set of psi gauges during the week to check pump psi. I guess my question is how much pressure should I have? Should I check it cold or warm or both? What does anyone think about the problems I am having?
Sorry to be so long winded but I was trying to give as much information as possible. Thanks ahead of time to anyone who may answer. Hopefully J, Schwiebert chimes in on this one!

Sounds to me like you have a shock load relief valve that has a cracked or broken elbow, its on the three point hitch internal cylinder.   Original elbow was common metal, replaced by steel.   You can see it by taking off the cover that the seat is bolted to.


A pressure gauge will only tell you the setting of the main system relief valve.   The ports that you will test are full of oil, if the pump can pump 3 or 4 drops of oil into the already full port it will show pressure.   You need a test device like a flow rater to test the health of your pump.   Yes it needs to be tested at operating temperature, warm enough that you can't hold your hand on the system.

Ok thank you for replying. So as I was reading your reply, I remembered having read about that elbow before going bad. One thing that I forgot to adjust and check is the free play of the three point at full raised position. I believe there is none right now but I have to double check that today. Would that affect the shock load relief valve? I believe it would. Will that also cause my steering issue? That top cover has been off the tractor recently because I can tell the gasket looks fairly new. But it was before I owned the tractor.

I do not know if I can get a flow rater to test the pump. Would you plumb it in the remote ports? I think I still will check the pressure with a set of gauges just to know.

Attn: J.Schwiebert- Hello I was just wondering if you had a chance to check you email that I sent you? I included the information and numbers I found while testing the 1600. No hurry I was just making sure the Email went thru, thanks again...

Don't mean to shoe horn in on another's post and if not proper please ignore... I have a similiar issue with my 1650 when the engine rpm is below 1300 the three point drops and when I speed the tractor up the three point raises again. So I removed the seat platform but could not seat the elbow referred to above. There is a bit of oil in the pan and I am assuming I need to get this oil out to see where is elbow is and what is all going on if it is in fact cracked or what. Does anyone have a picture that they could share so I would have an idea where to look?

No problem its always good to as questions to people who are dealing with the same problems you are having. Anyway the problem you are having seems to be possibly the same as mine. I have not had my top cover off yet so I cannot completely answer you question. It will be a few weeks till I tear into mine. I am pretty sure you will need to remove the fluid from the system to check that elbow and psi relief. Can you see the lift cylinder? Hows your steering? I know there are others on this forum that can answer your question. I know you do need to raise the engine rpm to lift the three point but 1300 seems a lot more than needed. I would say 800/900 is more like it, at least my 1800 and 1850 it seems to be around there. I did check my hyd. pressure after using the tractor the other day till it got hot and would not lift anymore. The pressure was good even then about 1900psi. I also timed how long it took the three point to come up @1900rpm, with nothing hooked to it. I took an average of four times and it was 1.8 seconds. I believe that my pump may be ok, its either that elbow and valve or the lift cylinder seal is leaking and not holding pressure or both. I am waiting to get in contact with J.Schwiebert to see what he thinks. Hope that helps some