How do I know which trim cylinder is bad?

[Greg68S]

1989 Mercruiser 5.7L V8
Alpha One Out drive
Engine serial
0C664458
Drive serial
0C796105
Transom serial
0C724496

My trim goes up and down normally but under load it won't go. The pump is working normally and my trim fluid I found to be extremely milky in texture. I assume that this is a moisture problem. So how do I know which cylinder is no good? The it will trim under a load under 15 miles an hour, after that the load is to great and won't push it. I have since flushed my fluid and replaced with new.
Thanks guys
-Greg

 

[alldodge]

Re: How do I know which trim cylinder is bad?

If your sure you got all the air out maybe its the pump. Pump should be around 2500 to 3000 up and 800 to 1000 down if you can find a gauge.

If your sure its the cylinders, but they usually show some kind of a leak don't they? When I was bleeding my Alpha before, I would leave them connected to the transom and move them in and out. In this position you could also watch it start lifting the boat when they came in comtact with the floor. I would be careful to not let it push to hard and damage something, but it may give you an idea.

 

[RRitt]

Re: How do I know which trim cylinder is bad?

it is probably the pump.

if it is not the pump then it is rust from water on a bypass valve inside one of the cylinders. In which case it does not matter which cylinder is bad because you need to rebuild both of them while also flushing all water out of the entire system.

 

[Greg68S]

Re: How do I know which trim cylinder is bad?

How do I rebuild them? Is there a kit? How do I know if its the pump or cylinders?

 

[Greg68S]

Re: How do I know which trim cylinder is bad?

I thought the pump was self bleeding..