800 COM hydraulics questions

This may be a little long winded, but...
I have an 800 COM gas. If I start the tractor after it has sat for a day and put a disk/4rw planter in the ground, it will raise the implement after the first round. However, after that when the tractor is running warm, the hydraulics (even after throttling all the way up) will not lift. I have made do.
Last winter I never was able to use the tractor/snowblower because something was frozen. I chalked it up to water in the hyd fluid that was crystallizing OR freezing in the Eagle Hitch lift cylinder. So last spring I changed the fluid. The hydraulics still wouldn"t lift any implement, but again I made do.
This winter, as long as the temp was above 30ish, everything seemed to be okay. But rarely do I need to blow snow then! There were times that the spout wouldn"t even turn, much less the hitch lift the blower.

So... I am thinking one of two things. 1) Worn out pump. 2) Filter

I am in NE SD and still have considerable snow on the ground so I have not had the chance to even look at the back end. Over the winter, though I bought a pump (the whole assembly). What to do next?
If I replace the pump, do I just pull the whole assembly off and put the new one on? (I don"t know much about hyd pumps) If so, can I find a gasket or will the "liquid gasket" be sufficient?
If it is the filter, is it something that is cleaned or is it paper? Can I find replacement ones?

I know this is long, but I am in search of help. I follow this thread and look to you experts to assist me. I am hoping to pick up a yellow 1070 later this month, and will probably have many more questions.

Thank you in advance!
Paul

Paul: Filter is behind a round, 3 bolt cover, lower right side of PTO-HYD Housing. Should have been serviced when you changed the fluid. They are available from CASE, but are meant to be washed & re-used. However, over considerable time, they get punky & need to be replaced. Before you begin to change pumps, check out the Relief Valve assembly on top of the valve body. Could be something wrong in there, such as a broken spring. To help those old pumps out, I add some 85W140 Gear Oil to the thin fluid.

On mine, I had the relief spring break. Changed it, and added a shim, now I have decent hydraulics.

The spring is okay. A guy told me to stack washers inside the assembly and that would help. I didn"t notice anything. I will start with the filter. I"m sure it needs replaced.

Dumb question: do I need to drain the hyd fluid before I remove the filter?

Also, when I changed the fluid I used SuperTech R&O anti-wear hydraulic oil (from Wal-Mart - same guy that told me about the washers told me to use this oil). Is that okay? Should I be using something else?

Send me an e-mail with your ph# and addy. I have a package to sent to you.
Loren

Forget wal mart for your oil. I bet part of your problem is your oil. It's foaming and causing the pump to suck air. Bet it's milky looking.
caseman-d

Caseman-d: milky looking is an adequate way to describe it! What should I be using? And are the washers under the spring okay?

Paul

Paul: I don't want to get into a discussion on oils, but I had a contractor, who owns CASE & CAT equipment, tell me he uses Wal Mart Lubes, their best, if he has a choice. I think you got something else going on. #1.If your relief valve is OK, & your pump builds so little pressure, I don't think more washers will help. I don't think it is building enough pressure to lift the valve. #2.Sounds like your pump is sucking air. I would check O10910AB Rubber Gasket that seals between the pump & the suction tube elbow.

John: Thanks. Three questions:
1) should I be using oil without detergent? I read somewhere that anti-wear hyd oil can cause foaming. Because the system is old, should I be using oil that is not so thin?
2) warning: amateur question... Is the suction tube elbow in the pump assembly or something that is/can be accessed from "outside"?
3) warning: super amateur question... Do I need to drain the oil reservoir in order to check the filter? It certainly appears to be low enough that if I remove the 3 bolts and pull the cover off my oil will spill out. I want to make sure that I am prepared to put it all back together once I start on it!

Paul: Hyd Oil is specifically designed to be anti-foaming. That's why it is designed for hyd. systems. A Transmission-Hyd. oil is better yet, because it has the anti-foaming properties, and also "Extreme Pressure" protection for the gears. I recomended adding 85W140 gear oil to the Transmission-Hyd. oil to thicken it up.

Pump & Valve assembly will need to be pulled to replace the seal. There is also the same seal on the return elbow. That should also be replaced. If either one of those seals are blown, it will churn the oil.

Yes, when you pull the filter, the housing will drain.

Thanks again John!! I'm hoping to take a look at this in the coming week. Your information is most appreciated. Can you answer two more questions for me?

1) if the wal-mart 'super-tech' oil is okay to use, should I continue using what I did OR should I switch to the Heavy Duty Tractor and Transmission Oil (http://www.walmart.com/ip/Super-Tech-Heavy-Duty-Tractor-Hydraulic-and-Transmission-Fluid/16213442). I don't currently have a manual (obviously) and I want to make sure that whatever oil I use is okay for this system. Concurrently, how much gear oil should I mix?

2) I assume there is a gasket between the pump and the tractor body? Is this a part that is available or can I use the 'gasket in a tube?'

Thanks again. As mentioned earlier, I am hoping to purchase a 1070 late April but for now the 800 is my work horse. I'd sure like to have the hydraulics working well before I start working dirt!

Paul