removing piston from tilt ram???? F225TXRD

[fairdeal]

So I want to replace the herniated oil seal on the tilt ram.

I've removed the t/t unit, and removed the tilt ram -

now I need to separate the piston from the ram so I can change out the seal.


According to the shop manual, I just hold the piston in a vise

(with a suitable non-scarring "special tool")

and un-thread the ram - presumably right-handed thread.




But looking closely at the piston - there's a tiny roll pin

Its not mentioned in the manual, not called out in the parts schematic.

It LOOKS like it must be pinning the piston to the shaft....

and if its not - WTF is it doing there?

[pstephens46]

How would you ever line it back up when reassembling if it extends into piston?

[pstephens46]

Unless there is a groove that extends completely around the piston.

[pstephens46]

Would it keep the piston from unscrewing itself from ram? Guess we will wait for Rodbolt and his Sat morning coffee?

[rodbolt17]

hold the TOP of the ram,where the anchor pin goes through, in the vise.
remove the torx screw making sure you don't lose the washer.
dump out the pins,springs rods and balls.
insert two 5/16ths bolts in the holes.
use a screwdriver and unthread the piston from the ram.

DO NOT mess with that roll pin.

[fairdeal]

THANK YOU, Rodbolt!

I really like the screwdriver/bolt trick!

Now, my first task this morning is to search the entire floor of my shop - on my knees -

I watched the g-d little ball slip out of my fingers -

and then it bounced and disappeared.....

[boscoe99]

Nothing like a gray ball on a gray floor.

The ball will take several bounces and then make a 90 or 180 degree in an different direction when you are not looking.

When you find it you will find it in the last place that you look for it.

[rodbolt17]

you were warned
those tiny parts tend to jump very well.

[fairdeal]

double happy ending!

Very interesting.
It turns out that that roll pin serves to capture the ball of a check valve (for air relief?)
I can barely see it down in there - but I can hear it rattle.




and, Rodbolts "bolt trick" solved both my problems!

Not only did it let me easily unthread the piston -

but as I applied the torque, the workbench shook -

and the missing ball suddenly reappeared at my feet!



btw, what do you make of that greenish material on the threads in the photo?

its hard/brittle - like epoxy

I've never seen green Loctite - but it seems the last time it was assembled, there was some sort of substance used..

[fairdeal]

Nothing like a gray ball on a gray floor.

The ball will take several bounces and then make a 90 or 180 degree in an different direction when you are not looking.

When you find it you will find it in the last place that you look for it.

you were warned
those tiny parts tend to jump very well.

True - mea culpa. I got real lucky that it turned up.

Although I was already resolved, if necessary, to proceed with some salvaged steel ball -

either from a Windex bottle pump - or motor bearing - or chair caster....

[rodbolt17]

that ball is to allow the tilt ram to drop back to the memory piston after impact.
that locking compound is done at where ever that unit was made.
I typically use gel seal or loc-tite 518.