1980 merc trim tilt issue.

[lemmer18]

I have a 1980 merc 90hp v6 2 cylinder trim cylinders. Internal mounted trim pump motor. Problem is that all of a sudden I can't trim my motor upwards. Motor runs and sounds good. Motor trims down but once down I can't get it back up. I have to release the pressure by unscrewing a bolt on the one cylinder to drain fluid and release pressure to lift motor back up. I think it has to do with the 2 wires coming from the trim tilt mount cylinders which might have to do with the trim limit switch. I ran into this problem once bc when installing the new trim pump I had those 2 wires connected incorrectly with the blue and green up and down wires so I switch them and never had the issue till now. I connected the two wires together to bypass the trim limit switch and still nothing. Any guidance would be appreciated thanks.

 

[Fun Times]

Re: 1980 merc trim tilt issue.

I think it has to do with the 2 wires coming from the trim tilt mount cylinders which might have to do with the trim limit switch.

Hi there, Does the trim pump motor have electrical power while trying to go up? Do you think it's a electrical power problem or a hydraulic type problem?

 

[lemmer18]

Re: 1980 merc trim tilt issue.

The trim pump motor runs. When. It seems like the hydraulic pressure builds up and locks when trying to lift the motor up. Not sure why it does that but last time when installing the trim it was bc of those two wires coming from the trim cylinders at the motor

 

[Chris1956]

Re: 1980 merc trim tilt issue.

If the trim motor runs in the up direction, then something is wrong with the hydraulics. First of all you have an inline six, right?

Trim limit switch keeps motor from running, so that is not your issue. You have a single solenoid on that PTT unit? It is connected to the blue wire, right?

 

[lemmer18]

Re: 1980 merc trim tilt issue.

Ya inline 6 and I have 2 solenoids one attached to the blue and one attached to the green. I tried I by pass them to see if it was a solenoid and it still did the same thing but not sure if I bypass it correctly just used the positive wire going to the ptt and touched it to the green and blue wires at the solenoid

 

[racerone]

Re: 1980 merc trim tilt issue.

If there are 2 wires going to the trim motor then I believe you might have to touch one of the power trim motor wires to + and the other to - on a battery.--Then reverse the wires to make it turn iin the opposite direction.

 

[lemmer18]

Re: 1980 merc trim tilt issue.

Well the two wires come from the drive side ram cylinder not sure what there for or do. Thought it wa the trim limit switch bug are those the wire u said that might have to go to the pos and neg. I had them going to the green and blue wires before and everything worked fine for about a 10 uses or so and now this problem

 

[Dukedog]

Re: 1980 merc trim tilt issue.

Ya inline 6 and I have 2 solenoids one attached to the blue and one attached to the green. I tried I by pass them to see if it was a solenoid and it still did the same thing but not sure if I bypass it correctly just used the positive wire going to the ptt and touched it to the green and blue wires at the solenoid

You should have two solenoids. One for tha up and one for down. 3 wire pump motor. If they pull in as they should and tha pump runs its like Chris said, hydraulic.............

 

[lemmer18]

Re: 1980 merc trim tilt issue.

So I took the trim motor out it runs good shoots fluid from the up and down ports. Motor I can lift up and down so nothing was ceized. I have the trim pump SAE J1171 with the plastic reservoir, the reservoir is slightly loose just can twist back and forth about a 1/4" to 1/2". It's always been like that so not sure if that's an issue. I'm leaning towards air was in the lines possibly.

 

[Chris1956]

Re: 1980 merc trim tilt issue.

SAE J1171 is a marine designation, not a part number. I would think that your motor came originally with a metal reservoir that was attached to the motor and pump upper with many perimeter screws. Sounds like you have some sort of Mercruiser PTT pump. You might post a picture.

 

[lemmer18]

Re: 1980 merc trim tilt issue.

Yea I purchased it from someone which did come from a mercuiser. The price was right. There's no nut for a relief valve the only information I could about the relief valve is that it's mechanically set to relief the pressure once a certain psi of for e is reached. So I'm not quite sure how I could bleed the ram cylinders to make sure the air is out of them. The PTT is usually self bleeding.

 

[lemmer18]

Re: 1980 merc trim tilt issue.

I took the trim motor apart and tested to see if it needed a rebuild or brushes cleaned worked good with alot of power.

 

[Chris1956]

Re: 1980 merc trim tilt issue.

OK, I know a bit about the mercruiser PTT units. Your OB trim cylinders have different sized trim hoses, so that cannot be mixed up. I think the Mercruiser trim hoses were the same size. So you must have some sort of adaptor to make it work. Also the Mercruiser pumps had two hose output. This was converted to a four hose setup on the I/O transom bracket. Where is your conversion done?

Do you have the correct up and down hoses on the PTT trim cylinder fittings? They would be easy to switch, if they were not different sizes.

 

[lemmer18]

Re: 1980 merc trim tilt issue.

Yes I have the two ptt lines coming off then they have a fitting to divide in 4 lines. I believe there in the correct locations. which lines are for what? white braided and black coated? Ones up and ones down. I can't remember what I had them at. I think braided I have on the up. Not sure though, I'd have to look again.

It all worked then one day it decided not to. I'm in the middle of purchasing used set of ram cylinders and hoses that came off of a workin unit. Maybe my hoses have been damaged but its so small I haven't notice any oil leak. I know iv bent the braided ones by accident acouple times. Not sure what they consist of inside but they are getting up there in age .

 

[Chris1956]

Re: 1980 merc trim tilt issue.

Original hydraulic hoses were black neopreme over white nylon braid, over rubber core. MerCruiser hydraulic lines were stainless braid exterior. Original PTT pump had a control valve mounted on it's bottom. Obviously the MerCruiser PTT system had a similar device, although it may be built into the pump itself.