Cylinder pin removal thoughts...

[wp6529]

I have to rebuild the stick/crowd cylinder on my Komatsu backhoe, the rod seal is now leaking too much to be useable. While I rebuild most of the cylinders myself, the stick/crowd and boom cylinders are just too damned big for my modified 36" pipe wrench pin spanner so I'll end up taking it to a hydraulic shop. Fortunately the boom cylinder looks to have been rebuilt at some point so it's in good shape.

The current challenge is removing the pins to get the cylinder out. The cylinder ends are the greased rotation points and they are nice and free and also no load on them as I have the boom cribbed in place and the hydraulic lines to the cylinder disconnected. The pins don't want to budge much in their fixed holes though, a bit of PB and hammer and they only move back and forth perhaps 1/16".

As there is not really any way to clamp some sort of brace to use a port-a-power style cylinder to push the pins out my current thought is to weld a 1/2" bolt to the end of the pin so I can couple it to the pull-back cylinder from my hydraulic KO punch set and then add spacers as needed to pull the pins out with the limited stroke of the pull cylinder.

I'm not going to be able to do this for a bit due to endless rain here, so I have time to ponder other options.

Thoughts?

 

[bc]

I don't know. Last time I couldn't open a backhoe cylinder and took it to the shop, I cried when I got the bill. Heat the rod end and melt some wax around the pin. It must still be in tension or binding somehow. Get your wife to hold a punch while you swing a sledge hammer. The pin might be bent just a little and the last resort is to cut it out.

I fought getting a hub off of a 6 foot mower that I had tipped up on its side. Had a chain double wrapped around it and a 12 ton hydraulic jack. Don't own a portapower. Supported the end of the jack with a ladder and blocks. Stood back away and pumped it tite. Still had to alternate applying heat with a rosebud and pumping on the jack. Had the pump lever pointed to the side so I could stand away cause when it broke loose everything landed on the ground.

I would like to see a picture of your modified pipe wrench. When I took my cylinder to the hydraulic shop they just put it in a big bench vice and 2 guys with chain tongs and a pipe wrench with a cheater pipe broke it loose. You might just need a long cheater and heat to break loose and unscrew the cylinder end. Of course you still have to get the pins out. Back in my oilfield days I couldn't break a well head loose with a 48 inch pipe wrench. Picked up a 30 foot joint of 2.5 inch tubing, slid it on, and walked it around.

Don't know if any of this helps. Good luck.

 

[wp6529]

I don't know. Last time I couldn't open a backhoe cylinder and took it to the shop, I cried when I got the bill. Heat the rod end and melt some wax around the pin. It must still be in tension or binding somehow. Get your wife to hold a punch while you swing a sledge hammer. The pin might be bent just a little and the last resort is to cut it out.

I fought getting a hub off of a 6 foot mower that I had tipped up on its side. Had a chain double wrapped around it and a 12 ton hydraulic jack. Don't own a portapower. Supported the end of the jack with a ladder and blocks. Stood back away and pumped it tite. Still had to alternate applying heat with a rosebud and pumping on the jack. Had the pump lever pointed to the side so I could stand away cause when it broke loose everything landed on the ground.

I would like to see a picture of your modified pipe wrench. When I took my cylinder to the hydraulic shop they just put it in a big bench vice and 2 guys with chain tongs and a pipe wrench with a cheater pipe broke it loose. You might just need a long cheater and heat to break loose and unscrew the cylinder end. Of course you still have to get the pins out. Back in my oilfield days I couldn't break a well head loose with a 48 inch pipe wrench. Picked up a 30 foot joint of 2.5 inch tubing, slid it on, and walked it around.

Don't know if any of this helps. Good luck.

I'm no stranger to opening hydraulic cylinders, this one is just too big for my tooling. 36" Harbor Freight pipe wrench ($25) and about 45min in the shop making a replacement for the pin-in jaw with a radius to match the cylinders it will fit and a 3/8 pin for the spanner slots. The moving jaw I just milled in a pocket for another 3/8" pin. Works fine on the cylinders it fits and some still require extreme torque. The cylinder in the back above the WB140 is the problem one, too big for the wrench to fit. The cross pins are also problematic.

 

[Janicholson]

I'm no stranger to opening hydraulic cylinders, this one is just too big for my tooling. 36" Harbor Freight pipe wrench ($25) and about 45min in the shop making a replacement for the pin-in jaw with a radius to match the cylinders it will fit and a 3/8 pin for the spanner slots. The moving jaw I just milled in a pocket for another 3/8" pin. Works fine on the cylinders it fits and some still require extreme torque. The cylinder in the back above the WB140 is the problem one, too big for the wrench to fit. The cross pins are also problematic.


View attachment 69433

Look for a pin or cross bolt keepimg it in place, a manual might help. Jim

 

[bc]

I'm no stranger to opening hydraulic cylinders, this one is just too big for my tooling. 36" Harbor Freight pipe wrench ($25) and about 45min in the shop making a replacement for the pin-in jaw with a radius to match the cylinders it will fit and a 3/8 pin for the spanner slots. The moving jaw I just milled in a pocket for another 3/8" pin. Works fine on the cylinders it fits and some still require extreme torque. The cylinder in the back above the WB140 is the problem one, too big for the wrench to fit. The cross pins are also problematic.


View attachment 69433

Ok. I'd like to see a pick of your modification. Might have to invest in a 48 for the big one. I forget how mine came loose but it was either a 36 stretched out to its last lug or chain tongs. A little hammering also helps.

I have a couple swing cylinders that need new seals. Plan is to cut a piece of plate and drill holes where the pins go. Use bolts for pins. Then weld a big nut or something on it or else cut the plate so it has its own handle that a cheater will go on.

Did you post this down on the backhoe forum? Might get some help there.

 

[wp6529]

Look for a pin or cross bolt keepimg it in place, a manual might help. Jim

Already removed, one of them uses a cross bolt, the other snap rings. Just parts that do not rotate and get rusted in place over the years so need some force to get out.

 

[Mule Meat]

I do not know the width measurements of the parts. Just throwing this out there for something to ponder while it's raining.
Ball joint press? If one will not work. It may give a little inspiration on Fabricating something.

 

[wp6529]

I do not know the width measurements of the parts. Just throwing this out there for something to ponder while it's raining.
Ball joint press? If one will not work. It may give a little inspiration on Fabricating something.
View attachment 69444

I have one, way too small. We're talking pins roughly 1 3/4" dia x 13.5"+ long that have roughly 4"+ at each end somewhat rusted in place. Big stuff.

 

[BarnyardEngineering]

If you take "preserving the paint" off the table, a whole new world of possibilities opens up for you. For example, you can't clamp something to push from, but you sure as heck can WELD something to push from.

 

[Fixingfarmer]

Step one fine someone younger and dumber with a bigger hammer. Use one of those pin holders for yourself so they aren’t calling you lefty this summer. 16 lbs sledge or better.
That failing it’s time for the broko torch. Lance that thing out. If not available normal torch will work just be careful of the ears both yours and on the ones the pin goes through. If you have to cut the pin out then work on it in pieces without the cylinder in the way. That sounds like a fairly skinny but long pin for what the application is it should come out pretty easy

 

[wp6529]

If you take "preserving the paint" off the table, a whole new world of possibilities opens up for you. For example, you can't clamp something to push from, but you sure as heck can WELD something to push from.

I considered that but concluded that welding a bolt on the end of the pin would be least impactful, would not damage the pin and was easily ground off. When the pins are out I can slap them in the lathe and polish them clean with so abrasive cloth. Have to imagine replacement pins are a bit pricey.

 

[WESnIL]

I would not pound on the end of the pin with a punch and sledge. Mushroom the end of the pin and you'll never get it out. Penetrating oil, patience, heat and rapid cooling with repeated applications of each would be my methods of choice. Your first indication of progress is whether you can get the pin to rotate.

 

[miangus]

I think someone above had it, a bigger hammer and someone younger to wield it. I would heat the pin with a torch, don't go crazy. Spray with oil, repeat. You want to expand the pin to crush the rust and then cool it to pull the oil in. I would try this cycle at least 5 times from both sides. This will work or find someone who has experience removing crawler track pins.

 

[wp6529]

The modified wrench which works on cylinders with end caps up to about 4 1/4" dia. Perhaps I just need to mod a larger wrench to fit the current 4 7/8" cap and the boom cyl cap which is about 5 1/2" dia. ETA: It appears a 48" wrench will only get me to 5" capacity which would do this cylinder but not the boom one. HF also doesn't appear to have a 48" option and the cheap one I find is $80.

 

[Fixingfarmer]

I would not pound on the end of the pin with a punch and sledge. Mushroom the end of the pin and you'll never get it out. Penetrating oil, patience, heat and rapid cooling with repeated applications of each would be my methods of choice. Your first indication of progress is whether you can get the pin to rotate.

Well I’ve done probably a thousand pins in this manner. The heat idea is good but how on earth you would mushroom the pin I’m not sure unless you go at smacking on the edge with the hammer directly. I found a picture of a fancier tool than I had but the idea is the same.

Hoss thumps the big end. You keep it in the middle. If it’s solid steel like mine wear gloves while holding the punch. This fancy cable thing isn’t necessary but it should get the point across.
This is what they are made to do if I stopped and made every pin rotate before I drove it out id still be out there fighting the first wheel loader pin. This is more on the order of a sprayer boom pin albeit a bit beefier most of those are only 1 and a 1/4 at the most but the Length is about the same. Most heavy equipment pins are going to be 2 inches around or better

 

[Charles in Aus.]

Could the pin have worn and have a ledge in the centre ? This might be stopping it from moving . Levering or blocking up the base of the cylinder ever so slightly might just let the pin slide past if that's the case .

 

[wp6529]

Could the pin have worn and have a ledge in the centre ? This might be stopping it from moving . Levering or blocking up the base of the cylinder ever so slightly might just let the pin slide past if that's the case .

I don't think so, it's moving with great difficulty, i.e. rust buildup, the cylinder isn't showing any sign of being pushed to one side it shifts back and forth by hand easily.

 

[Janicholson]

I'm no stranger to opening hydraulic cylinders, this one is just too big for my tooling. 36" Harbor Freight pipe wrench ($25) and about 45min in the shop making a replacement for the pin-in jaw with a radius to match the cylinders it will fit and a 3/8 pin for the spanner slots. The moving jaw I just milled in a pocket for another 3/8" pin. Works fine on the cylinders it fits and some still require extreme torque. The cylinder in the back above the WB140 is the problem one, too big for the wrench to fit. The cross pins are also problematic.


View attachment 69433

A portapower in that configuration has far less pulling power than pushing power due to the cylinder ram being on that end.

 

[wp6529]

A portapower in that configuration has far less pulling power than pushing power due to the cylinder ram being on that end.

That is the 5T rated pull back ram. I doubt the wrench could withstand anywhere near the limit but it did take a good amount of pull to get that end cap loose.

The current problem cylinder is on the backhoe and is too large dia for that wrench to fit. The stuck cross pins are also a lot longer than they are on the loader.

 

[mike in mo]

2 plate of heavy steel some 1/2 inch chain and a bottle jack that works on it side. Cut a hole in one plate for the pin to pass thru chain the plates one on each side with the jack on the pin and crank away.