Mercury 115 1979, power tilt question

K

Krockd

Recruit
Joined
Mar 25, 2012
Messages
2
Hi all, I'm a noobie. from NZ. I have just had a 79 merc 115 hp put on my old boat. Having troubles tilting up...very slow. From what i've read and done so far it has air in the lines that needs to be bled out. I have the twin hydraulic model with pump in the boat. I have loosened the flat head and the hydraulic fluid that is coming out is frothy full of micro bubbles, the tilit motor itself is going fine but you can hear the sound change as it hits the air.
My question is - where is the reservior for topping up? - I can let the stuff out ok but I'm not sure where to fill it again - guessing on the pump (in boat) but what am I looking for? also what is the best fluid to use.
Thanks in Advance :)
Justin
 
C

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
28,922
Re: Mercury 115 1979, power tilt question

That system has the resevoir mounted directly under the PTT motor. Look for a stainless slotted round head screw on the top right of the rectangular resevoir. That is where the 5W-30 motor oil or ATF is introduced to top it off. Figure out what is in there already and add more of it, until it reached the base of the threads. The PTT resevoir is self bleeding.

The trim cylinders have two bleed screws each. With the motor in operating position, unscrew one of the flat head slotted screws next to the grease fitting on the top end of the PTT cylinder. Run the PTT motor down until all the air is out. Reinstall the bleed screw. Repeat with the other cylinder. Now unbolt the PTT cylinders and turn them so the Hydraulic hose attachment point faces up. Remove the bleed screw next to the attachment point and run the PTT motor in the down direction, until all the air is out. Replace the bleed screw. Now repeat with the other bleed screw.
 
You must log in or register to reply here.
Top