Trim up with a bang

Hello I have a 1972 Fiberform with 6 cyl inline 165 HP. My son asked me to raise the drive unit (It was submerged in a lg water tank so I could run it). I hit the up button , he said it was moving slow and then let out a loud bang and moved smooth and faster until reaching the up limit. However the catch basin under the engine turned very red . Fluid continued to come ot of a red hose that is at the rear of the engine and is directed to the catch basin.. I thought the worse thinking it is the motor/pump unit, but that drain hose is connected to a gizmo Ithink a reverse lock vave??? So folks what made the noise and how do I fix leak and insure it doesn.t happen again. Boat Shop is Out of the question poor man here. HELp Jim Athol Idaho

Re: Trim up with a bang

What outdrive?

Re: Trim up with a bang

MC-1 I believe, whatever its the original for the year..Somebody out there must know something. it seems like I get few replies on anything I inquire about..

Re: Trim up with a bang

fayjim2 said:

Hello I have a 1972 Fiberform with 6 cyl inline 165 HP. My son asked me to raise the drive unit (It was submerged in a lg water tank so I could run it). I hit the up button , he said it was moving slow and then let out a loud bang and moved smooth and faster until reaching the up limit. However the catch basin under the engine turned very red . Fluid continued to come ot of a red hose that is at the rear of the engine and is directed to the catch basin.. I thought the worse thinking it is the motor/pump unit, but that drain hose is connected to a gizmo Ithink a reverse lock vave??? So folks what made the noise and how do I fix leak and insure it doesn.t happen again. Boat Shop is Out of the question poor man here. HELp Jim Athol Idaho

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Sounds like you blow a hydraulic line from the trim pump. The red fluid is ATF. With a loud bang as you described it shouldn't be hard to find the blown line. My question is 'why' did the line blow. Maybe one of the rams is stuck.

Re: Trim up with a bang

That line should be attached to something gonna have to figure out where. That will be the first thing to replace. Maybe some pictures ?

Re: Trim up with a bang

fayjim2 said:

MC-1 I believe, whatever its the original for the year..Somebody out there must know something. it seems like I get few replies on anything I inquire about..

Click to expand...

You may not be getting a lot of replies if you don't provide enough information on the first post. It seems to happen more often with newer members. In this case you didn't originally give the model or type of the outdrive and there are a lot of different ones out there. Also, as the saying goes, a picture is worth a thousand words.

I can't help much with your problem since I only have outboards and don't know much about outdrives. Get some pictures and post them. There are a lot of very smart folks here that will help figure out what happened and help to get you running again.

Re: Trim up with a bang

It didn,t blow a line, the fluid actually came out of a drain line that I now have traced to the reverse lock something or other. I guess that means that would be the component that failed but why? I talked with a person the other day and he said if I had the shifter in reverse and trimmed up it should have stopped but it sounds like hydraulics may have overcome the reverse lock and broke it. Is this possible? Now I have more questions, I really haven,t been able to find one of those items and is it possible to change this system out with something more functional. naturally without a half a truckload of money. I,m thinging about putting a plug in that drain line any comments.. Thanks Jim

Re: Trim up with a bang

I'm not I/O guy but it doesn't sound right. My GUESS is that as soon as the trim reservoir is empty the trim will stop working. Plugging the line will most likely only work until the line bursts.

Re: Trim up with a bang

There is no drain line on the hydraulic circuit it is sealed. There is no reverse lock to keep you from trimming in reverse. You can put it in reverse and trim the drive all the way up if you want (not recommended). Everything is held in place by hydraulic pressure. Once again a picture is worth a thousand words. If you have fluid coming from a hose it is broken. Plugging the line will prevent it from working at all because the fluid in the cylinder either can't go out from the tank to the cylinders or can't come back to the tank.
Even if there were a "revese lockout" of some kind it would electrically disable the pump not hydraulicly.

Re: Trim up with a bang

OK, this belongs in the I/O section. I will move it there.

To fayjim2,

Yes, more info will lead to better replies. What many will figure is if you can't describe the items well, that you should probably not be working on it. It's not a criticism, it's just good advice. Suggesting modifications, and referring to a drain line help confirm those concerns. Again, nobody is trying to be critical, just help you understand why reply quality is down. My suggestion at this point is to go to a good Mercruiser mechanic. I am assuming it is Merc because of the MC1 info. We really need more help from you to be more helpful back though. Hang in there and we'll do what we can. Good luck!

Re: Trim up with a bang

Yes pictures are nice but I,m not the person able to do that right now. HOWEVER I really apprecate all the help so far.To make some more avaliable and to further my knowledge I did some book reseaRCH ON MY OWN.This boat is 1972 Mercruiser powered rig. There are some components on this thing that are not on a few years later. The Reverse lock is one of them which is a electric/Hydraulic item. That is where this I will now call it a line without a fitting on the end that I want to call a drain is connected but the open end conveniently ended up lying in the engine pan, making me think it is a drain. Sooo where does the end of that line go, I,ve looked it over until I was looking crosseyed. I have one more item also, on this era of Mercruiser the Reverse lock valve prevents trimming up/out while in reverse. So I,m still looking for the problem and if you have goof first hand info I would appreciate it. A mercruiser Mechanic garge is out of the question Thanks Jim

Re: Trim up with a bang

Find your manual here http://boatinfo.no/lib/library.html

I think it is this one: http://boatinfo.no/lib/mercruiser/manuals/mercruiser1.html

On this page http://boatinfo.no/lib/mercruiser/manuals/mercruiser1.html#/768

This old system looks very complicated compared to the newer ones

and here is the hydraulic schematic : http://boatinfo.no/lib/mercruiser/manuals/mercruiser1.html#/778
on the top right of the page.