Mercury Power Trim Help

[umfangler]

I have an old Merc with power trim. I just got the boat/motor and the previous owner told me I need to fill and bleed the trim system. What type of fluid is used and what's the procedure? Here's a picture of the port side cylinder and another of the pump.<br />Thanks<br /> http://i11.photobucket.com/albums/a174/umfangler/DSCN0247.jpg <br /> http://i11.photobucket.com/albums/a174/umfangler/DSCN0248.jpg

 

[82RAYSONCRAFT]

Re: Mercury Power Trim Help

Normally it will take a 30wt oil, but will need some more info, Like how old? Is the oil level on the dip stick at proper level. A lot of things could be wrong from low oil level, bad piston cylinders seals, bad o-rings in the pump motor hydraulics, electrical problems. Provide Us with a little more info as to about what year of manufacture and more detail as to Hyd or Elec troublshooting.

 

[Laddies]

Re: Mercury Power Trim Help

Never use 30# oil in a trim system, if you don't know whats in it use dextron it mixes well with anything, some of those style cyl. have bleed screws at the top, some must just be run up and down to get the air out and remember to ck the fluid level when the engine is up--Bob

 

[Chris1956]

Re: Mercury Power Trim Help

Umfangler, That system usually uses 5W-30 oil. It is not self bleeding. There is a 4-5 step process to bleed the system, in the service manual. Basically, you need to unbolt the trim cylinders from the motor, leave them in a verticle position, remove the top bleed screw (next to the grease fitting) and run the trim motor "down". When the oil comes out of the bleed hole without bubbles, replace the bleed screw on that cylinder and repeat for the other cylinder. Now, turn the cylinders over and lay them flat. Remove one bleed screw, near where the two hoses attach. Run the trim pump "Up" until the oil has no bubbles. Replace the bleed screw and repeat for the other cylinder.

 

[SeaKaye12]

Re: Mercury Power Trim Help

I have a 1977 Merc 850 and the Owner's manual that comes with it states to use SAE 5W-30 oil in the Tilt/Trim system.<br />Thanks for reading, Chuck

 

[jheron]

Re: Mercury Power Trim Help

By the lack of paint on the cylinder starting at the top bleed screw I would say that some one put brake fluid in the pump I would flush it out with plenty of fresh 5w-30 and check it for leaks <br />With your pump system its self bleeding... make sure the vent screw (next to the fill screw) is always open and just run her up and down a few times untill she's not spongy any more! <br />Jon

 

[timmathis]

Re: Mercury Power Trim Help

Wal-Mart has tubes of power trim fluid 12 oz $2.97<br />I have the same system. I just use Dextron 3 atf fluid(works well)$2.19 for 16 oz. Just fill and go up & down a few times and refill. If it is leaking at a fitting be careful and do not over tighten.