Help .... Frozen hydraulic pivot pin

   / Help .... Frozen hydraulic pivot pin #1  

Navvet

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I have a 1.5" hydraulic cylinder pivot pin that is seized and will not come out. It moves easily on the cylinder end but is frozen to the sleeves in the square channel on either side.

The pin was held in the sleeves with vertical drift pins but over the last 30 years moisture has gotten in them and rusted the pin to the sleeves.

All the others I have removed came out with a few taps from a hammer and a 1" steel punch.

I tried welding a 1/2" bolt to the end and turning it out, didn't budge.

I have used heat (Oxy / acetylene torch), various penetrating oils (WD, PB, etc), no go.

I made the jig in the pictures with 5" channel and used a 10 ton hydraulic ram, no go.

I have just about run out of ideas, I am thinking about cutting the cylinder out with a hack saw blade and then working on either side's sleeves individually, but I don't want to take a chance ruining the cylinder.

Any Ideas ???

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   / Help .... Frozen hydraulic pivot pin #2  
There come's a time when hiring a pro is cheaper than presisting with non-production. In this case profeciency with a cutting torch is what you need. In NM,LA,Tx and Ok outstanding metal workers can be found in the oil field industry. In NC,they might work at large mfgring plants or ship yards. You might ask for advice on "Weldingweb".
 
   / Help .... Frozen hydraulic pivot pin #3  
If there is enough room between the cylinder eye and the boom, slip a sawzall blade in there and cut the pin to free the cylinder. Provided the pin isn't hardened.

Then use a drill (again if it isn't hard) or a torch and blow the bulk of the pin out of the pin boss. Then try heat. Try heating what's left of the pin (making it swell). Then rapidly cooling with water (shrinking) and it will break rust loose. Or take a die grinder or your sawzall and cut what's left of the pin (after you made it hollow with drill or torch). That will relieve the press fit.

Using your jig with 10ton ram....did you try brute forcing it? Or did you put pressure on it and smack it with a hammer. You'd be surprised how that will break a pin loose.

A logsplitter also makes a good horizontal press with a bit more tonnage.

I can think of half a dozen different things I would try. But don't know your equipment or skill level.
 
   / Help .... Frozen hydraulic pivot pin #4  
There come's a time when hiring a pro is cheaper than presisting with non-production. In this case profeciency with a cutting torch is what you need. In NM,LA,Tx and Ok outstanding metal workers can be found in the oil field industry. In NC,they might work at large mfgring plants or ship yards. You might ask for advice on "Weldingweb".
Definitely need a pro with a torch. Could also use a carbon-arc.
Either way, expect a shower of molten steel in your face. Must have the correct PPE
A mask, not goggles, full leathers, etc.
 
   / Help .... Frozen hydraulic pivot pin #5  
I have a 1.5" hydraulic cylinder pivot pin that is seized and will not come out. It moves easily on the cylinder end but is frozen to the sleeves in the square channel on either side.

The pin was held in the sleeves with vertical drift pins but over the last 30 years moisture has gotten in them and rusted the pin to the sleeves.

All the others I have removed came out with a few taps from a hammer and a 1" steel punch.

I tried welding a 1/2" bolt to the end and turning it out, didn't budge.

I have used heat (Oxy / acetylene torch), various penetrating oils (WD, PB, etc), no go.

I made the jig in the pictures with 5" channel and used a 10 ton hydraulic ram, no go.

I have just about run out of ideas, I am thinking about cutting the cylinder out with a hack saw blade and then working on either side's sleeves individually, but I don't want to take a chance ruining the cylinder.

Any Ideas ???

I'd recommend you drill it out using a mag drill.

 
   / Help .... Frozen hydraulic pivot pin #6  
I like the mag drill idea. Also ideas:
1. Weld black pipe on end and use huge pipewrench
2. Cut pin with hacksaw or sawzall and get cylinder out of the way
 
   / Help .... Frozen hydraulic pivot pin #7  
First I’d try the sawzall blade between the cyl and frame, using another person to constantly dribble water on the blade. Lennox makes a diamond grit blade if its hardened but doubt that one is.
Second I would try a 90 lb pavement breaker and lots of air (1.00” air hose).
Third, an Oxy-lance torch with 90 psi of oxygen and bore a straight hole from both sides (making sure it goes completely through). and fire blankets and leather cover ups cuz the blazing H-E-Double hockeystick fire from damnation of molten steel will be aiming right for you…….. Then the 90lb pavement breaker after it’s cool.
 
   / Help .... Frozen hydraulic pivot pin #8  
Do you have a welder? If so then this should work: Drill a hole as large as possible a little deeper than than the thickness of the bushing. Then run weld beads on the inside of the hole. It will work better if the welds are run concentric to the hole. But if you need to run the welds lengthwise that's OK. As the welds cool they will shrink and thus shrink the outside diameter of the pin. Then the pin should practically fall out. I have used this method more than once and it has always worked.
Eric
P.S.
If you have a cutting torch you can blow metal out of the center of the pin instead of drilling. You will still need to run the weld beads.
 
   / Help .... Frozen hydraulic pivot pin
  • Thread Starter
#9  
Just an update, we have been able to move the pin a 16th to an 8th of an inch using the jig and a sledge but it just won't go through. Too much flex in the square tubing to allow me to push with full pressure. Next step is using the hacksaw blade to cut the pin and drop the cylinder out of the way and then just work on each sleeve independently.

There come's a time when hiring a pro is cheaper than presisting with non-production. In this case profeciency with a cutting torch is what you need. In NM,LA,Tx and Ok outstanding metal workers can be found in the oil field industry. In NC,they might work at large mfgring plants or ship yards. You might ask for advice on "Weldingweb".

I am keeping the "Pro" as a last option. I'm retired, stubborn, and cheap and don't want to admit defeat yet.

If there is enough room between the cylinder eye and the boom, slip a sawzall blade in there and cut the pin to free the cylinder. Provided the pin isn't hardened.

I'm hoping the pin isn't hardened. I'll find out in a few days...

Using your jig with 10ton ram....did you try brute forcing it? Or did you put pressure on it and smack it with a hammer. You'd be surprised how that will break a pin loose.

Pressure and a sledge have help move the pin a bit. Look at my last picture and how the 1/2" bolts and the channel with the pipe have bent.

I can think of half a dozen different things I would try. But don't know your equipment or skill level.

As far a skill level goes, I still have 3 active brain cells left over from the 70's ...

I'd recommend you drill it out using a mag drill.

That mag drill would be nice. I was thinking about rigging my benchtop drill press over the arm. May try that if the sawzall doesn't work out...
 
   / Help .... Frozen hydraulic pivot pin #10  
You have a welder. Weld a bar to the pin. At least 3 feet long and try turning the pin. You're looking for a tiny movement with lots of penetrating oil. Strike it in alternating directions. You might torch the center of the pin opposite the bar to help. If you get any movement, then try the opposite direction. If it moves at all, you'll get it free.

Edit.. YOu posted an update that you can move the pin. Unless you've mushroomed the end, rotation is the way to get it out. The rust builds a wedge that stops the movement. Alternating directions with penetrating oil to flush out the wedge material is the solution.
 
 
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