Alpha outdrive trim not going down

My outdrive is all up(out) hydraulic pump runs. Nothing happens when I try to run down(in) I think it is an oil dyne power trim control system. Where do I start?

 

Welcome to the form.

You probably have a stuck valve in the pump. Try getting someone to push (down) on the drive leg (hard) while using the trim down switch. Naturally, you'll want to be on the trailer, or have a swimmer do chin ups on the ventilation plate, if in the water.

You can also try using a small (light) hammer (less then 10 ounces) and lightly tap around and on the pump housing, again while using the trim down switch. This can free up a stuck valve too.

Lastly, you'd be best advised to pick up a manual for this drive/engine package. They're cheap (usually about 30 bucks retail) and run through all the diagnostic information. It would also be a good time to "level the playing field" by preforming the routine maintenance, that's needed on these assemblies. This way you know where you stand with the engine, drive, tilt/trim, etc. More importantly, you'll become intimate with the workings and condition of the various assemblies, so you know what you'll be looking at, the next time an issue comes up and probably a good idea where or what to look at for the specific symptom(s).

 

This is a 18ft Baja with a Mercruiser alpa one. It has been sitting a couple of years. The trailer switch took it out but cannot trim down. It is on the trailer. I will try to stand on it. I just got the manuals, but reading was not clear for this problem. Do I need ignition on? The maintenance level checks etc are clear. Thanks for your reply.

 

No, you shouldn't need ignition on, though try it anyway, in case there's a short or some crossed up wiring.

When boats sit, they tend to lock up and once freed can continue on their life cycle. You could pull the cylinder pins on the drive and see if they move, without the weight of the drive on them.

 

Clean the cylinder shafts with warm water and some detergent if you didn't do that already, then spray them with WD-40 or equivalent. The cylinder seals on the shaft are a very tight fit, when salts accumulate it gets even tighter.

Then proceed as PAR told you. Do not keep pressing the switch too long if the leg won't come down, otherwise you might ruin the relay on the pump bracket.

 

It may also be a bad solenoid. They can be bypassed with jumper wires to test the pump motor works both ways. If the problem is in the valves you should hear the pump running, but nothing moves.

 

Alpha outdrive not going down

Thanks to all for the tips. This was my first crack at using a website chat for help. The trim down solenoid klicks but no pump run. Bypassed and put 12 volts on the green connect to the motor. Worked good. Looks like I need a new solenoid. The trim up(out) doesn't even click the solenoid. Could be another issue maybe switch. Although the trailer mode trim raises(out) ok. This solenoid should be okay. I think replacing both solenoids would be a good idea. thanks guys until my next problem

 

Replacing the solenoids certainly is a good idea because they are the main cause of hydraulics failure.
Part of the interior in these cylindrical relays is a thermoplastic that gets deformed by heat if corrosion of the contacts causes an internal voltage drop or the buttons are pushed too long.

Use rectangular automotive relays 12V/40 Amps or larger as replacement. They cost just a fraction of these "marine" types and are much more reliable.

 

if the cylinders are blocked or siezed up the pump will work but the oil will only go around in a circle via the relief valve.

wet alloy hydraulic cylinders are high maintence... take the rams off and service them.

 

Pull out the trim switch and jumper the common and down wires. More than likely, the trim switch is defective...Don't forget that this is an item that takes a lot of physical abuse...it should be the first place to look for problems.

Cheers, DocWet [ Everything has limitations...and I hate limitations.]