1978 johnson tilt/trim issues

[parttime]

Hi everyone,

I'm new here on the forum and new to Iboats. I've acquired an '82 model boat with a '78 Johnson seahorse 150. I got the boat for free so if I spend a few hundred and use it for a season or two great, if not, well it was free. I'm having an issue with the trim and tilt. I've removed the electric motor and rebuilt it myself to get it working. now the motor works and the pump is working somewhat but I feel like its not building sufficient pressure of its not bleeding itself out. The system doesn't appear to be self bleeding because theres no vent that I've found. I am operating the trim using the three wires and a battery with the engine separated from the boat. the two smaller cylinders are actuating although one is slower than the other. I can extend and retract them. the large cylinder in the center will not actuate and it sounds as though theres alot of air moving around inside. the manual release valve on the side blows a ton of air and foamed fluid out if I crack it after actuating the unit a couple times. I'm looking for some answers on actual operation and repair. the original problem as I was told, was that the motor portion had failed, although it only had a frozen bearing/bushing. with that resolved I am currently in the process of trying to fill the unit with fluid and bleed to check for leaks before installing everything back on the boat. any help that can be offered will be greatly appreciated. I am an automotive technician and have the ability to troubleshoot the system but I have to have a good understanding of how it's supposed to work before I can figure out whats wrong. thanks again

 

[Joe Reeves]

Re: 1978 johnson tilt/trim issues

The PTT unit is actually self bleeding internally. Keep the manual release valve closed excepting when it's necessary otherwise to manually extend the cylinder and trim rams.

The tilt and trim rams must be extended fully in order to fill the units reservoir.

The trim rams, when the unit is removed from the engine will move independently of each other due to the missing weight factor. These trim rams also are designed to move slower than the main tilt ram.

 

[parttime]

Re: 1978 johnson tilt/trim issues

thanks for the quick reply. essentially what you're saying is that i need to mount the engine back on the boat to keep the reservoir upright and tilt the engine to full extension and fill the unit. After this it should self bleed back to the reservoir. how much fluid should it take?

 

[Joe Reeves]

Re: 1978 johnson tilt/trim issues

No, it doesn't need to be back on the engine. You can do the job on the bench. Just have it in the proper position as if it were on the engine. The reservoir needs to be filled to the overflowing point.