how to diagnose a cracked power trim cylinder?

mallardtone-man

Petty Officer 2nd Class
Joined
Sep 22, 2008
Messages
110
I posted recently about an issue I am having with my power trim pump where sometimes when it is trimmed part way up it will refuse to go up any farther. It will go down and I have to trim it all the way down before it will go up again. Sometimes it goes back up right away, other times I have had to repeatedly hit the down button while the pump is already bottomed out. it will make a squealing sound of sorts when I do this, I never hold the button down for more than maybe a second when doing it for fear of damaging the pump.I doubt this is good for the pump but don't know too much about how the system works. when I am having this issue I get zero noise from The pump or motor when trying to trim it up, not even a Click, I have had people suggest that the fluid may be low or contaminated but at least one person thought it sounded like a cracked cylinder. I have not had a chance to check the fluid yet, I I am just curious as to how I can accurately determine whether or not the cylinder is cracked. also if this is the case what does it mean for my pump? Is this something that can be replaced or rebuilt or am I looking at a whole new unit? Thanks in advance for any help james
 

schematic

Lieutenant Junior Grade
Joined
Jan 12, 2008
Messages
1,102
"I get zero noise from The pump or motor when trying to trim it up, not even a Click" Not a cracked cylinder if this is true. Check for voltage at the motor when unit fails to rise. Sounds like bad switch/relay/wiring issue.
 

Ant-Knee

Petty Officer 2nd Class
Joined
Oct 14, 2011
Messages
139
I think you have 2 relays,
One for up and the other for down..
They should be the same relays as one another,
You can try and switch them and see if the problem switches to down instead of up, If so I would think you have a bad relay...

Ant...
 

Ant-Knee

Petty Officer 2nd Class
Joined
Oct 14, 2011
Messages
139
Oh yea, Forgot to mention, You may also need to bleed the air out of the system...

Ant...
 
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