1150 power trim and tilt hoses

utfyrfytr

Petty Officer 2nd Class
Joined
Jul 14, 2014
Messages
190
Can someone tell, or show me where each hose connects to the pump unit for the PTT? This is on a 1975 1150 Merc two cylinder system. I know they can really only go two ways which gives me a 50/50 chance, but I don't want to have to take it all apart again after filling and bleeding the system. I took this apart 1-1/2 years ago and my marking system seems to have disappeared. Thanks for any help.
 

Jhoppy

Petty Officer 3rd Class
Joined
Oct 30, 2009
Messages
77
I don't think you can hook it up wrong the small ports are hooked together in the pump and the large ports are hooked together in the pump. The small lines just go to the small holes the large lines go to the large holes. Just don't strip them out is aluminum as I recall
 

utfyrfytr

Petty Officer 2nd Class
Joined
Jul 14, 2014
Messages
190
I assumed that it would make a difference which port the starboard or port side was hooked too. Are there valves in the pump that directs the fluid when the corresponding switch or button is pushed and the lines are just going to a resevoir so to speak?
 

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
27,953
The PTT hoses connect to a control valve bolted to the pump/reservoir. That control valve allows for the motor to kick up, if it hits something, as well as allows the motor to hold trim at full power. The pump runs in both directions to pump oil to the up side of the control valve or the down side of the control valve.
 

merc850

Commander
Joined
Jul 7, 2010
Messages
2,046
Bolting the unit to the transom can cause rotting where the bolts break the fiberglass, and may pull out if you hit big waves and don't sit the unit on the stainless steel part of the hose.
Just connect the hoses to the outlet which put them closest to their ram - make sure that there's slack in them because they move when operating and when they're connected follow this bleeding procedure power-trim-bleedingsmall.jpg
 

merc850

Commander
Joined
Jul 7, 2010
Messages
2,046
This is my factory bracket (drawn from memory) it can be easily made from 1/8" aluminum and will provide a solid mounting considering the G forces involved.
PT-bracket.jpg
 

utfyrfytr

Petty Officer 2nd Class
Joined
Jul 14, 2014
Messages
190
Ok, have the hoses hooked up. I have never had the PTT before so wondering on the workings of the switch. If I push the top button by itself nothing happens. If I push the middle button the engine raises maybe an inch and then stops. When I push the bottom button the motor goes down and when I push the top and middle button together the motor raises to the trailering position. Does this sound like the control switch is working correctly?
 

GA_Boater

Honorary Moderator Emeritus
Joined
May 24, 2011
Messages
49,038
Yes, it's working.

The bottom and middle switches are for trim as you figured out. The trim up stops when the trim limit is sensed and shouldn't be raised anymore when running the boat. The top trailer button and trim up are used together to bypass the trim limit to tilt the motor to the trailer position.

So it's working properly.
 

merc850

Commander
Joined
Jul 7, 2010
Messages
2,046
You can adjust the limit switch so that the motor stops at at the right out angle using just the "out" button. This has to be done on the water Loosen bolt "C" in image and turn "B" all the way in - trim the motor all the way in and accelerate to full throttle then trim it out until the motor just starts to over-rev, turn nut "B" out until the pump shuts off - tighten "C" back up. This might need some trial and error and don't let the motor continuously over-rev; I put the tilt pin in the first hole near transom.
limitswitch.jpg
 

utfyrfytr

Petty Officer 2nd Class
Joined
Jul 14, 2014
Messages
190
GA_Boater and Merc, thanks for the information, it's good stuff to know and helps out a lot. I didn't make my pump mount as fancy as your drawing. I just took a piece of 3/4" ply wood and 2-10" "L" brackets from Home Depot bolted the ply to the brackets the pump to the ply and the brackets to the deck. Not sure about the G forces you mentioned. I ran the trim and tilt up and down a number of times without the pump bolted to the deck and it never moved. After I get everything else finished I may then take the time to make a more professional looking mount. Thanks again for all of everyone's help, I'm sure I'll be back again looking for advice.
 
Top