Help .... Frozen hydraulic pivot pin

[MinnesotaEric]

Penetrating oils don't really work until the stuck bit starts to move, then they start to work. Alternatively, you can try heating and then hit it with oil to try to draw the oil in to loosen then stuck bits.

If my heat it up and hit it with the biggest air hammer you get your mits on doesn't strike your fancy and neither does lancing it out, then you can try heating, and rapid cooling with a hose over and over until the thing cracks loose as you would with the stuck exhaust header bolt.

 

[RancherGuy]

Penetrating oils don't really work until the stuck bit starts to move, then they start to work. Alternatively, you can try heating and then hit it with oil to try to draw the oil in to loosen then stuck bits.

If my heat it up and hit it with the biggest air hammer you get your mits on doesn't strike your fancy and neither does lancing it out, then you can try heating, and rapid cooling with a hose over and over until the thing cracks loose as you would with the stuck exhaust header bolt.

They work for me. I had a 1950 Ford tractor that sat out in the humid weather for decades. It had a locked up transmission and I bought it that way. I wanted to give my father the front axle, so I put penetrant on all lug nuts - front and rear. A day later, added a little more. A day after that, more. On day 4, I put a socket wrench to them and they all acted like they were installed the week prior. If there is movement, my experience is that there is faster action, but even without movement there is success because it penetrates just like the water that entered in the first place. Like you say, sometimes the approach used requires consideration of available time.

 

[JPRambo]

This stuff if you can find it, is amazing. As said earlier a couple squirts in morning and again at night. A couple days and it's free. Not as cheap as WD-40 but works tons better.

 

[metalbender]

The exothermic lance will do it in minutes, what's the hold-up?

 

[Big Barn]

The exothermic lance will do it in minutes, what's the hold-up?

Thank you....

 

[efox]

Retired oilfield machine shop welder kicking in my 3.5¢. Some good ideas here and as I’ve done this kinda thing daily for years I’ve found out nothing works on everything every time. My attack procedure became to try the simplest thing that likely would work and move up in difficulty and time demand as needed. Most, if not all these suggestions have their time and circumstance.
I would avoid for now the oxy or air lance on that small pin since it is unlikely that you can gouge through without gouging the frame bosses-or cylinder sleeves. If you do that you may as well have cut them out with a torch and replaced them. The saws all is a good idea but it may take some time to cut through and then you’ll still have to press the pin parts out.
IMHO the best shot is with the mag drill. It’s hard to make a solid pin or shaft shrink if it doesn’t have a space to shrink into. What usually binds, if the pin isn’t doglegged, is the boss or sleeve in the rect tube beam being pushed elliptical by the flex in the beam. If you can’t block that solidly very close to the bore, the press is actually jamming the pin in tighter. In a 1.5 dia. pin that center hole will be best if bored at least 3/4”. Any bigger will help but the goal is to provide a space for the pin to contract into.
Step 2: heat the pin from the inside bore. The idea is to expand the pin and compress the rust or scale tightening the fit, then to allow the pin to cool and shrink into the annular bore. You need not do that with a welder. It does tend to quick heat and self quench but if you fill the hole with weld metal you may not gain as much shrinkage as if it were left open. Differing opinions but I’m my experience you are better off not to quench. It may crystallize and cause the pin to break when pressed. Time is on your side and there is no real hurry to cool it down. Anything below 300° and you can cool with water or oil and finish the shrinkage. Better to pull than push the pin but unless you have a hollow center ram and are real good at welding a pull rod on that is probably out.
Now for the real radically, extreme suggestion: rebuild the cylinder in place. Remove the packing gland/nut while the cyl base is attached, remove the cyl from rod and piston, remove piston and packing nut from the rod end, rebuild and replace.

 

[CADplans]

When the pin is distorted, or galled on the end,, force is almost impossible as a method to move the pin.
The distortion or galling is actually increasing the diameter of the pin,,
Pressing, or hammering must then distort the mating part to get the pin to move.

Oils do not help when the issue is an interference fit,, a pin that is galled on the end is an interference fit.
Pressing, or hammering, beyond a reasonable amount,, only insures the mating part will also be destroyed.

This is not a threaded joint, it is a pin, in a hole.

Threads respond to penetrating oils,, pins,, not so much,,

Cut the pin, save the mating parts. the pin is the low cost item to replace.

 

[wdchyd]

Navvet, after you get it out have your hyd shop cut at piece of hyd rod stock for a pin. It’s made from 1045 medium carbon stock and will work nicely. You might get lucky and he has a chunk in the scrap bin.