Outdrive slowly goes down

[cfpyne]

I have a 1976 Mercruiser Type 1 outdrive. When I put the outdrive in the up position it will slowly return to the down position. I see no visible signs of leaks. Any suggestions asa to what to do?

 

[hoot]

Re: Outdrive slowly goes down

since you don't see leaks, i would be thinking the trim cylinders. another place to look/feel is under the trim pump oil tank. there is a manifold underneath with several orings. the orings can break and leak allowing the unit to fall.

 

[kayakndave]

Re: Outdrive slowly goes down

Had this identical problem just a few weeks ago, and with help from this board - Problem solved. Although it's a Volvo Penta outdrive, I was told it was not the trim cylinders, but the tilt/trim pump assembly. A check valve at the pump goes bad and causes an internal leak-by, thus causing the system to loose pressure, and the outdrive will slowly drop down. I used it all last summer in this condition, adjusting the trim back up every ten seconds or so, but it finally got to the point where it wouldn't hold at all! Replaced the pump assembly, and it works like new again.

 

[cfpyne]

Re: Outdrive slowly goes down

Thanks for the replies. I have already replaced the o-rings on the manifold as they were leaking, but the problem is still there. Is there a way to check the check valve in the pump assembly?

 

[rodbolt]

Re: Outdrive slowly goes down

yes it is testable. but it takes some special gauges. it may be best to have it done. the hydrualic pressues may be over 1000 psi on certain tests<br /> good luck and keep posting