125 HP power tilt and trim

hello all,
ive been having trouble with my power tilt and trim pump. after many hours frustration and 2 failed valve body rebuilds, i finally decided to bite the bullet and spend the money for a new valve body.
my question is- what is a good brand of fluid to use? seeing as it is a new part i would hate to ruin it by using the wrong fluid or too heavy of fluid (which suits some of my diagnostic findings). every manual ive seen just says #20 weight oil. it does not specifiy as what type- motor oil, hydralic etc. however, it does say NOT to use automatic transmission fluid which is what i used to troubleshoot my problems based on abundance and availibility. since then it has been flushed of ATF.
any advice would be helpful. this is my very first boat and i will be visiting these forums often. thank you in advance

~specialist z

Re: 125 HP power tilt and trim

Motor oil.If it doesn't work right after you clean it out then contact RRitt he rebuilds them.220779892902 E-bay this is his site.J

Re: 125 HP power tilt and trim

Which new valve body will you install? The one from ebay or something else?

Re: 125 HP power tilt and trim

shakazulu said:

Which new valve body will you install? The one from ebay or something else?

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they are all the same these days. They are made from softer aluminum, have lower grade steel, single regulator, short posts, and have metric threaded end plugs with allen key. The price difference is how many times it is being stepped on between you and china. I think they are fine for smaller engines 70 and under. As horsepower increase the softer metal in check valve is going to be a bigger and bigger problem. I doubt they will last more than a couple of seasons on a 150HP ski boat.

A US company used to make them - API i think. The US made ones were equal to the original, if not identical to the 1989 design. It could be argued that they were better since they were only making the most durable revision. The original went on to use threaded end plugs and adjustable regulators. Both were substantially easier to make but slightly less durable. The threaded end plug in particular had a problem with internal swelling on 120-150Hp that would cause the check valve to burst. If you can find a new API then buy it. It will serve you as good as new.