Stern drive stuck in up position

[roemere]

My stern drive in my '77 SRV 220 is stuck in the full up position after being stored that way this winter. Tried standing on unit while trying to lower it--no luck.

Shafts are not stuck/froze, I loosened the hydraulic lines a little (to allow pressure to release) and was able to push the unit down a little without problem (some fluid was pushed out as well). Re-tightened hydraulic lines then tried to operate power trim but it would not go up or down.Pump "runs" but not sure it is doing anything.

I figure likely the pump is bad? Solenoids? Read about a valve that could be stuck...where is this valve and how can I check/release/replace the valve?

Would replacing pump and solenoids likely solve issue?

 

[Bt Doctur]

what color was the oil released? What style of trim pump?

 

[roemere]

Color was pretty clear/clean. Reservoir by pump says use motor oil...not sure about pump style...

 

[Bt Doctur]

As long as your hear the pump running ,solenoids are working. http://www.*******.com/merc/Techbk/94/94hsa6.pdf replace the*s with b,o,a,t,f,i,x no comma`s
This style pump?

 

[roemere]

Pump doesn't look like that one...

 

[roemere]

How do I find the correct pump model so I can get a replacement?

 

[peterkvs]

I had this problem on another boat and it would get stuck in the up position if I ran it to the upper stop. I had to crack loose the line going from the pump to the cylinder that pushes the out drive up and relieve the pressure. Then it would work fine until I ran it all the way up again. Real pain. Must have been a stuck check valve in the unit. I never did fix that before I sold the boat.

Good luck. Pete

 

[roemere]

I had this problem on another boat and it would get stuck in the up position if I ran it to the upper stop. I had to crack loose the line going from the pump to the cylinder that pushes the out drive up and relieve the pressure. Then it would work fine until I ran it all the way up again. Real pain. Must have been a stuck check valve in the unit. I never did fix that before I sold the boat.

Good luck. Pete

I loosened the "up" lines to relieve pressure and was able to push unit down a little (some fluid came out when the unit was pushed down), but after reconnecting lines, still cannot raise or lower the unit with the pump. Pump "runs" (I hear it spin) but doesn't seem to actually move any fluid. How do I find the replacement part number to buy a new pump? Is there some valve that could be stuck? How do I test for stuck valve? Where is valve located?

 

[roemere]

Pump has "74436" and I think "A2" on it. Found a 74436A9 online. What are my options for replacing the pump? Does number have to match exactly?

 

[scoflaw]

With the lines cracked or off, the rams should compress completely not just a little. I would disconnect the rams from the drive completely to make sure your rams aren't seized.

 

[roemere]

I was able to push them down about 1 to 1.5 inches. Could have gone further, buf didnt want to push too much fluid out, and didnt want them stuck down so I can trailer it in to shop if necessary. And when I say I pushed them down, it really did not take a lot of effort...

 

[roemere]

Can I use a 74436A9 trim pump unit to replace my original 74436A2 trim pump unit? Is the 74436a9 just a newer version of my 74436a2?

Or is there an after-market replacement for my 74436a2? Everything I can find online says they no longer make/sell model 74436a2, and can't find a new 74436a9, only used/rebuilt....

I have a 1977 Mercruiser 888.

 

[scoflaw]

Why not take yours apart to see where the problem is. Might be a real simple low dollar fix

 

[KC_Sundancer]

Why not take yours apart to see where the problem is. Might be a real simple low dollar fix

I agree, I'd take the old one apart first. Nothing to loose, it could just be a stuck solenoid valve.

 

[roemere]

Why not take yours apart to see where the problem is. Might be a real simple low dollar fix

While I would feel comfortable replacing the complete part (disconnecting wires and hoses, then re-connecting them), not so sure about taking something apart and then trying to put it back together again--not even sure I would have the right tools for that....

Anyone know if the 74436a9 is the same as 74436a2? Can it be used as a replacement?

 

[roemere]

Now I am really confused. Called MercuryMarine customer support to see if 74436a9 can be used to replace 74436a2. They told me there is/was no such part number as 74436a2. He could only find the 74436a9. Mine definitely says a2 and I also found other references online to the 74436a2 model.

 

[CliffA]

will the outdrive lower (by gravity) if you take both rams off the outdrive?......with both rams disconnected from the outdrive will the rams move in and out when the pump is operated?

cliff