520 hydro that sat 5 yrs

[300zx 7]

This is the same 520 I mentioned in the RS engine forum. I am now getting ready to install the engine and see how the hydro does. As I mentioned in my other thread, the tractor sat unprotected for the elements for 10 to 15 hears. So it has taken a while to free up all of the control linkage with PB Blaster. My current plans for the hydro are to just change the oil and filter. The questions I have are:

1. should I add any seal conditioner to soften up any rubber parts, and if so what kind?

2. is there any other maintenance I should do on the hydro before trying it out?

3. after running it for a while, should I change the oil? I don't expect I will get all of the oil out of the system on the first drain, like a car automatic transmission there will be oil in the system that will get flushed out the first time I run it and cycle the lift cylinder.

As always, any advice would be appreciated.

Here is another picture for those interested. I am electrostaticly cleaning a part every 24 hours. This is a first for me to use this process, but so far it is working well on the rust, grease and paint.

[bgrizzle 0]

Nice horse if i have found with the seals as long as thiers no cracking in them you can take some trans fluid and rub it on the seals to bring them back. As for the Fluid change drain it and flush with kero then replace it hydro fluid did this on a 74 1250 cub and it sat for 15 years and havent had a problem with it. :thumbs:

[300zx 7]

bgrizzle, when you say "flush", do you mean pour keosene in, let it sit over night and drain, or do you mean run the hydro on keosene for a few minutes and then drain? These hydros use 10w30, so keosene would be mighty thin for the hydro. I have used this method on gear drives, but I must admit I am new to hydros. Did you change the filter before or after the keosene?

[bgrizzle 0]

Let it sit overnight and change filter after.

[rickv1957 76]

How did oil look that was drained out,any water,Rick

[300zx 7]

Rick, there was a tablespoon or so when I pulled the plug. The oil was fairly dark, but no red rust look, and it drained thinner than what I would have expected from 10w30. The dip stick showed it was full and there wasn't any rust on it like I have seen on the 8 speed gear drives. Again, realize this is my second experience with a hydro. When I was restoring the C161-h earlier this year, the oil drained like 10w30 and was much clearer. No water in it. I have seen water in the gear drives because of worn out shift boots, but I am curious how water got into the hydro unless it was condensation.

[300zx 7]

Well, I decided today I am going to try 3 qts of 10w30, 2 qts of transmission fluid and change the filter. Transmission fluid is high detergent and should clean out any sludge. I will run it for a while with no loads and then drain it out, refill with 10w30 and change the filter again. Unless someone says "whoa, don't do that", that is where I am headed.

[bgrizzle 0]

Sounds good let us know how it works it alway good to have more than one idea. :thumbs:

[pfrederi 18,971]

Early Sundstrand hydros used ATF (Type A Dexron) Later models used 10w30or40wt Motor oil. The Wheel Horse Sundstrand manual was pretty adamant about not mixing the 2. You could convert from ATF to oil but the system had to be completely cleaned out....

I know you have an Eaton so I do not know if the same advice is pertinent....but may be cause for rethinking....

Maybe something like Marvel Mystery oil instead of ATF....