Merc hydraulic trim/tilt pump replacement

[Bane333]

Hi,

I am new here so I apologize if I am not posting in the appropriate section.

My trim/tilt pump went and i bought a replacement pump.

My original pump had two solenoids to control the up and down function of the tilt. The new pump only has one solenoid. Will this still work?, can one solenoid operate the tilt to go up and down?

According to the previous owner he had one solenoid operate it up and down. Just wanted to confirm this.

Any help would be greatly appreciated.

Thanks in advance.

 

[alldodge]

Howdy

Sounds like you bought an old used one. In the two pics below, which one is your old and which is the new one?

 

[Alumarine]

It should work.
There's just the positive and negative connections that goes to the battery as well as the 3 wire connector that goes to the trim/til control right?

Are you using it on a I/O or outboard? It's important to get the right one.
I believe the hose manifold on the bottom of the pumps is different but can be swapped.

 

[Bane333]

AllDodge: they both look like exactly like the pump in the second picture.

Marc C: yes and its an Inboard/Outboard 120 Hp merc 1979

 

[alldodge]

OK, then you have an older pump then the one you started with. You can either rewire it or take the relays off yours and install them on the other, or change wiring

 

[Bane333]

This is a great diagram. Thanks!

So should I use the one or two solenoid system? The pump I bought has one solenoid, and only one solenoid controlled up and down.

I mean I could put my two solenoids from the other pump on this new pump but is that necessary? will the new pump work if I change it from one solenoid to two?

Sorry if this is a stupid question.

 

[alldodge]

From the looks of the wiring it is just plug and play, no need to change, they both use 5 connections. If the plug is the same, then no need to rewire.

The new pump is just like the old one, it just uses a different solenoid

 

[Bane333]

Okay great, thanks so much for your help.

Once I change the pump do I need to bleed the hydraulic system? Everywhere I read it says the air will come out by itself once i run the tilt up and down a few times. I was just going to do that with the vent screw open. thoughts?

 

[alldodge]

It should self bleed by running in/out. If a cylinder was rebuilt then it is best to remove lines. If you did cylinders I'll post the procedure

 

[Bane333]

That's exactly what I read. No I didn't do the cylinders.

I also replaced the trim limit and trim sender. I know they are suppose to hook up to blue and purple sleeve wires and a brown sleeve wire and round, but the new trim limit and sender wires are all black so does it matter which of the two wires i hook up to where?

 

[Grandad]

The blue and purple wires lead to a simple switch contact, so there should be no concern for polarity. They're interchangeable. - Grandad

 

[Bane333]

Thank you all for your help!!!! Greatly appreciated. Maybe now i can finally put my boat in the water after a year.