Trim Pump problems for Mercruiser 188HP 74 Slickcraft

[Sandman70]

Hello Everyone,
I have a 1974 Slickcraft with a Ford 302 Mercruiser 188HP motor. The trim pump has been giving me problems on an off for a couple of years and recently I noticed a leak. Turns out the o-rings falling apart between bottom casing bolted to the pump body. I replaced them and hooked all wires up again and everything worked great for a couple of weeks with no leak. Then I started just getting a click sound with no movement. I double checked the wires and ended up hooking everything up and then would work for a little while then nothing again. Now I can hear the sound of the pump running normally but no movement on the motor. Fluid is good, power looks good, sounds like it is running but the motor won't move. I am assuming the pump is shot and I will replace. However if someone out there has experienced the same thing please let me know and what you did to resolve. Thanks in advance!

 

[wahlejim]

Double check your connections, make sure they are clean down to shiny metal. What outdrive do you have? I had an MC-1 that was acting similar. Check the rams and make sure they are not bound up on bad gaskets. If you remove the rams from the outdrive and remove the hoses going to them, you should be able to move them in and out easily by hand. If not, they are the cause of the problem. When it comes to power trim systems, each part is expensive so it is best to be sure of the problem before you just start throwing money at it. Also check the Mercruiser forum, those guys helped me out a lot already. Even just reading the postings, I have learned a lot of information about my boat and where to start looking for various problems. For them to help, you will need models and serial numbers. The more they know, the more they can help you.

 

[Sandman70]

Wahlejim, thanks so much for the response. You will probably laugh however I don't know what the rams are. I can tell you I loosened the one of the lines going to the lower unit and I was unable to move the motor up or down. At least it is in the full down position. However you are right, I should be able to move the unit up and down. I will post on the mercruiser forum once I figure out what rams are.....LOL. I usually have a mechanic handle it but they are all too busy.

 

[Sandman70]

Well, I just googled it. If I disconnect both fluid lines going to the lower unit the lower unit should move freely. I guess then I will know.

 

[Sandman70]

I disconnected both lines and yes the rams are fine as the motor moves (lower unit) moves freely. So I picked up a different trim pump, hooked everything up and just got a "click" when trying to go up or down. I must have something not quite right on the wiring and can't figure it out.