1999 F100 power trim leaking fluid out top dust seal

[wasabe1995]

The power trim on my 1999 F100 TXRX has slow leak out the top dist seal. Other thanthat it operates properly and is in good condition. I wanted to try to change the inner seals but have trouble getting piston assembly (#4 in parts diagram) out of the shochk absorber cylender (#35 in parts diagram). Does anyone have advise on how to dissassemble it? Does it remove from the top by removing cylender end screw (#6) in order to get to inner o-ring seals?

Also, ther appears to be some vertical grooves on one side of the inside of the cylender (#35) ? I'm not sure if thes grooves should be there or if they got scored in and by internal metal to metal and I need to replace entire assembly? There did appear to be some fine metallic particles in the fluid when I opened it up causing me to think Par nomber 35 is damaged? Anyone know if this part is supposed to have verticale grooves on the inside or should it be smooth all the way around?

[99yam40]

I really have not looked at what you are talking about, but if o rings have to seal against something them grooves will not allow it to seal properly.
Metal in the fluid will mean a complete disassembly to inspect and clean all parts

[vr4rhoads]

all you need to do is remove the end cap and replace the seals, if its your tilt rod then your hurting cause youll have to take the motor off the mount to replace it. if its a trim rod then its not bad, hardest part is getting those dang caps off! They are torqued on good and the spanner wrench for them is expensive. I just made my own out of aluminum, tried the other day to get the caps off but the bolts I was using as studs bent (they are 4mm, they were rated 8.8 so not hardened) so I went and ordered some 12.8 rated bolts so really hardened bolts to wrench those caps off. you can also use a punch but they might mess up the end caps. also you might be able to borrow a spanner wrench from a boat shop.

[boscoe99]

Might want to look at this particular trim and tilt assembly.

There is no standalone tilt piston and there are no standalone trim pistons. It is an integrated unit.

There is a cap within a cap.

A Yam is not a Yam is not a Yam.

The F100 trim and tilt assembly has been known to whip a mechanics ass.

I don't know of any Yamaha that has to be unmounted for the trim and tilt assembly to be removed and replaced.

[vr4rhoads]

yeah thats different haha, as far as the tilt, thats what I was told, havent taken it off yet waiting on my hardened bolts and they ill find out if thats the case or not. but read that the rod wont come out with the motor sitting on its supports, rod is too long I guess (70 hp yamaha) but like I said ill find out this weekend

[99yam40]

If too long then retract it some

Did you notice he said there was metal in fluid?