Air in power trim system or ???

[nigxlzodiac]

Noticed that last season that my 2004 F100A would trim itself up slightly when under hard deceleraton or coming off the plane.
I guessed it may be bushes on the upper or lower pivot points of the trim motor / ram.
I did see some slack in the lower mount so changed them for new but I noticed that on full tilt I could still force the ram up by maybe 10mm by lifting the lower unit by hand.
I have checked for fluid level and it seemed full as it dribbled out of the fill hole.
Boat was slightly downhill however and also with the trim motor connected up it's also naturally downhill anyway.
Would it be a good idea to disconnect the lower mount so that the motor hangs vertically to check for level?
I'm guessing I have air in the system??

[robert graham]

Is this creating a problem for you?...or are you just worried about it?

[99yam40]

does it go back down to where it was or stay there?

[TownsendsFJR1300]

Crack the manual bleed screw loose and re-tighten.

If it's slightly loose, it'll bleed down and not hold the engine.

[nigxlzodiac]

Is this creating a problem for you?...or are you just worried about it?

Not a problem more of a concern

[nigxlzodiac]

does it go back down to where it was or stay there?

It goes back down, making me think air or a valve that doesn't shut off maybe.

[nigxlzodiac]

Crack the manual bleed screw loose and re-tighten.

If it's slightly loose, it'll bleed down and not hold the engine.

Ok will try tomorrow. It does stay up fine for weeks when on the mooring though in fact it doesn't creep at all.
Thanks

[99yam40]

Did you open the manual release and lift the motor by hand a few times to see if that would work some air out?

[robert graham]

Maybe no problem here???

[TownsendsFJR1300]

Just to clarify, quote:

"would trim itself up slightly when under hard deceleration or coming off the plane."

Is the engine T&T motor turning on OR the motor moving physically on it's own(no T&T power)? And is the motor when NOW up, stay there?

[pstephens46]

Putting the motor in reverse with a good bit of throttle should do the same thing.

Once while bleeding, I didn't get the manual release tight enough. I think it only calls for 5 lb ft of torque. Didn't want to over tighten the sorry flathead. I would lose my trim position while running...

Doubting this is the op's issue unless he had been using the manual release prior to the issue.

[nigxlzodiac]

Just to clarify, quote:

"would trim itself up slightly when under hard deceleration or coming off the plane."

Is the engine T&T motor turning on OR the motor moving physically on it's own(no T&T power)? And is the motor when NOW up, stay there?

No the trim motor isn't running just motor moving physically which leads me to think I have air in the system. Yes the engine stays up under its own weight fine.

[nigxlzodiac]

Putting the motor in reverse with a good bit of throttle should do the same thing.

Once while bleeding, I didn't get the manual release tight enough. I think it only calls for 5 lb ft of torque. Didn't want to over tighten the sorry flathead. I would lose my trim position while running...

Doubting this is the op's issue unless he had been using the Manila release prior to the issue.

No I havn't used the release at all since owning the engine.

[TownsendsFJR1300]

I gather no change loosening and tightening the manual release screw?


Take a look at this video, it may help:
https://www.youtube.com/watch?v=nfPyXNQQOf4

[nigxlzodiac]

I gather no change loosening and tightening the manual release screw?


Take a look at this video, it may help:
https://www.youtube.com/watch?v=nfPyXNQQOf4

It's tomorrows job unfortunately, my day ran away.