Mercury Power Trim Stuck/Blocked

[Segal_ZA]

Hi All,

I have a Mercury Power Trim off a 60 hp, 3 wire unit like this one below


The unit will not move up or down, I get a small amount of down movement if I help push on it.
I have stripped the entire T/T and checked/services all parts. I cannot find anything wrong. The only thing I noticed was that if I blow compressed air into the below hole it is completely blocked. Ive worked out that this hole feeds the bottom of the cylinder and pushes the ram up. Is it normal that this hole is completely blocked?
Does anyone have any advise about this or anything else I can check. The motor is strong so its not that. It seems like the bottom passage that pushes the ram up is blocked



Thanks
Dani

 

[Texasmark]

Never had a PTT problem so this is just speculation: Simplistic in nature but surely you had the unit sitting upright with either ATF or PTT fluid filled to the top of the service port (threads) when you tried to operate it.

Could be a check valve requiring hydraulic pressure to force it open. Since most compressed air is 100# or less, may need more pressure to force it off it's seat.

Any reason to expect the unit is not functional? History from source where you purchased it? Assume you have it wired across a battery sitting on a work bench sort of thing. Tried reversing the power numerous times to purge any air that may be trapped, preventing it from functioning normally? Just random thoughts since nobody has tuned in on this, maybe this will get them respondiing.

Edit: 3 wire to me means a common power lead with the other two being ground being selected by one or the other, causing the direction of current in the DC motor to reverse, reversing the direction of motor movement. You wouldn't by chance have your connections to the battery on the wrong terminals?