Mercruiser outdrive won't go down.

[Oregonbythesea]

I have done a lot of reading but can't find an answer to this question. It is a 76 Mercruiser 888. The outdrive goes up quick and fast, no problem. When I push the down button the motor runs and oil pumps (I unscrewed the aft line on one cylinder) but the outdrive won't go down unless I stand on it. It doesn't matter how many times I put it down and bring it back up, it still won't operate by itself in the down position. It does start to go down but only a little, about 10th of the way. I cleaned the pump and used an air hose on the opening of the valve assembly to make sure they were clean. The cylinders look good and when disconnected, they move freely in both directions. Any ideas anyone?

 

[Bt Doctur]

Re: Mercruiser outdrive won't go down.

try reversing the up/down lines for the cylinders.if it now goes down but not up , could be a pump problem with the down pressures,if it dosent go down , the trim rams may be leaking internally .There are rebuiding kits available (o rings ans seals)

 

[Oregonbythesea]

Re: Mercruiser outdrive won't go down.

BTdoctur, thanks for the quick reply. I can't believe the questions posted on this site in one day. That's a lot. As to my problem, I will reverse the lines and see what happens. I put new "O" ring kits in both cylinders and was hoping it wasn't my work that is the problem. I was wondering about the slide valve in the valve body. Can it get stuck and if so, what happens? Thanks again for the quick and sensible answer.

 

[Bondo]

Re: Mercruiser outdrive won't go down.

I put new "O" ring kits in both cylinders and was hoping it wasn't my work that is the problem.

Ayuh,.... Did it work Before you fixed it,..??

No idea what the problem is but I once had a girl friend like that, I traded her for a different model.

Ayuh,.... Quite a few different models......

 

[Bt Doctur]

Re: Mercruiser outdrive won't go down.

when you repaired your cylinders did you remember to install the grey top hat looking thing in the tube end closest to the transom?

 

[Oregonbythesea]

Re: Mercruiser outdrive won't go down.

Now it really got weird. I swapped the two line on both cylinders. When the up button was pushed, nothing. When the down button was pushed, nothing. The pump runs though. I lifted the outdrive by hand and operated the down button (to lift the unit) and the untied the rope I had holding it up. It stayed up. I operated the up button and nothing happened. I operated the down button and the unit went down a few inches. I operated the up botton and the unit came all the way up again. I put the two lines on each cylinder back where they were and checked to make sure the aft lines went to the aft lines on the cylinders and the rear most lines on the gimbel housing went to the rear most lines on the cylinders. Any more ideas? And, thanks again for any good input. This problem is driving me crazy. I also forgot to mention that I by-passed the indicator valve assembly and the reverse lock valve.

 

[picklenjim]

Re: Mercruiser outdrive won't go down.

You may need a good system bleeding, especially if you had the lines off pushing the rams in and out by hand.Always be sure the reservoir never goes empty while bleeding.With the drive up if you were to disconnect one of the up lines the drive should fall by itself.If it does try this.Raise the drive.Be sure reservoir is full.Crack open the up line so the drive starts to fall real slow.At the same time have someone hold the switch down.When about halfway down tighten the line to stop the drive falling and let off switch.Refill reservoir.Crack open the line again and hold switch down.When all the way down run back up and see if it will come down now.If not repeat.If it does, run up and down a few times and it will bleed the rest of the way itself.Remember to always keep the reservoir full.

 

[Oregonbythesea]

Re: Mercruiser outdrive won't go down.

Picklenjim, thanks for the advice. I will try it in the morning and report back.

 

[fieldja3]

Re: Mercruiser outdrive won't go down.

Did you have any luck with your trim issues?? I am having a issue myself with my trim when there is a load on it.