Power Steering Pump Issue
 

Yesterday I started my boat to warm it up and after about 3 minutes I saw smoke out of PS pump. I shut down engine and the pump was HOT . This is the second pump in 4 years. Something is going bad inside the pump because the pulley doesn't seem to be turning smoothly when turning by hand. I had a used spare pump. After installation I filled up the pump with ATF and turned the wheel while the engine was running.. No noises, worked fine...As the day went on a few hours later I was parking in a slip and if I turned the wheel all the way to the left or right it would start to screech.. But only while holding it all the way to one direction. 1992 Fountain with Imco external steering hooked to old style Saginaw inside transom. 2 power steering pumps failed in 4 years... Tired of buying pumps...help!

With the engine running and the cap off does the fluid look like it has alot of air in it? You could have a leak on the suction side and it will not leak fluid... Causes the pump to cavitate.

There is no air or bubbles. When I first pump the pump in yesterday and started it up, I turned the wheel all the way to one direction and then back. No squealing or any noise. Checked the level and it was good , no foaming either. Every once in awhile I see some red fluid in the bilge. I have looked for this slight leak and can't seem to find it. Its definitely not on the pressure side, possibly on the return but its not consistent. one day there will be some fluid and the next day nothing.. I always check my level several times a day. I was wondering if there is a difference between marine and regular automotive pump. Is there a pressure difference?? I'm going to flush the system today. Drain the fluid from the pump and the external steering and put new ATF in. Is ATF ok.. or should I be using Mercruiser clear PS fuild
thanks for your reply

The pumps will always screech when you are at full lock. It is hard on them, so avoid doing that.

ATF is fine.

Drained all ATF and replaced with mercury power steering fluid. Flushed 3 times and no screeching.. A mercury mechanic said that the mercury oil is synthetic and will not break down as easy as ATF. We will see what happens now..

Took me two seasons to finally figure out my PS issue..turned out to be the low pressure return line..had a small pin hole leak in it, and would cause the fluid to leak out and cause problems. I would just check, or replace the line, its simple to do, esp since you said you seen fluid in the bilge sometimes..

could it need a power steering cooler???

Power steering cooler is part of the oil cooler in back of motor.. 3" diameter. Oil temp cruising 3400 rpms is around 215.. I heard 1 screech today .Is there a way to make sure its flowing smoothly. Should I drain it again and blow air through the system to make sure nothing is clogged?. Should you see oil movement looking in pump?. Thanks for your replies.

according to some they say the marine P/S pumps used with full Hyd steering use a bearing on the shaft vs a bushing which can cause this issue..ck with AGR on their marine pumps...hardin also sells the same pumps..not cheap..I put one on mine not long ago when I went to full hyd...also was told to use only GM high performance non-foaming power steering fluid...

I have twin cable steering not full hydraulic. The Imco actuators hook up to the Saginaw control valve inside the transom, Came this way from Fountain