Frozen Pins

[hotsacks]

I've got to get a stabilizer cylinder off to replace the seals.I can't get the bottom pin out,the one closest to the pad.I've tried heat,soaking with WD,and a combination of both (great flames!!!). Am I going to have to cut this sucker out?No amount of beating with a sledge moves the thing.With snow coming soon,and a 1/4 mile driveway,I;m getting desperate.Any old hands here have any tricks up their sleeves?

 

[smalltime]

Would spraying the pin with a fire extinguisher work??
Maybe heat the parts around the pin then spray the pin with the extinguisher, I think it should cool it quickly, possibly shrinking it enough to drive out.

 

[Squizzy246B]

Only thing I can think of is a hydraulic puller/pusher or use a mag base drill. Both specialised operations that you will need to contact some pros for advice with. Enerpac make great hydraulic power packs which are hand pump operated.

http://www.enerpac.com/

You either need a bridging structure or to drill and tap the pin to attach a pulling point. Hiring a mag base drill and carefully boring it out will be extra time consuming and you will need specialist drill bits. I'd be loathe to try this.

Without seeing the arrangement a treatment of heating and rapid cooling can work but you need to know what your doing. Do you have a hydraulic repair shop nearby? they may be able to advise.

 

[xkvator]

try and rotate the pin? ...or weld a big nut on the end...or if you can get it on, get a big pipewrench & pipe for a handle extension

 

[hotsacks]

Yeah,I tried the pipewrench method with a 3' pipe breaker bar.Nada.
Haven't tried the heat/freeze process.Sounds worth a try.But I'd like to hear from someone who's actually chased this bear...and whupped it.Seems like a problem a lot of people with old equipment are going to run into.

 

[Dwan Hall]

could you post a picture of it. I work around old equipment but need to know what I am looking at first.

 

[Wulf]

If you can get a new pin I wouldn't mess around... I'd just lance the centre of the seized pin out with a cutting torch

 

[digger242j]

No amount of beating with a sledge moves the thing.

Actually, that might be part of the problem. Beat on them too much, and you can mushroom the end--not so much that you'll notice it with your eyeballs, but enough that it'll no longer fit through the hole. You might already be to the point that burning it out is the only solution.

 

[hotsacks]

Yeah.The Mushroom Effect has started.Next problem after the first problem.I figure I can grind the end bulge down AFTER (IF) I can get the thing to move.I'm not sure cutting it out is the way to go.Too much heat on the ductile and I've got a deformed hole.

 

[Wulf]

I'm not sure cutting it out is the way to go.Too much heat on the ductile and I've got a deformed hole.

If you try and blow a hole through the centre of the pin (from both ends)leaving the outside intact it shouldn't damage the pin bosses or the cylinder rod. Such method is used on seized track master pins and it works every time with no damage to the link bosses.

 

[DigDug]

My theory would be to put on more heat. HEAT, HEAT, HEAT, Maybe you have , but most times generous heat will expand metal and the internal part can be driven out . BUt..... if normal heat wont work heat both female ends up cherry red beyond your liking and and try driving out pin. Is the pin stuck in the end of the ram bushing or is it stuck in the actual outrigger flanges? Guaranteed if enough heat is applied maybe more than once the pin will break free from where its seized. Good luck . doug

Pics would be a great also.

 

[rino1494]

If you can get a new pin I wouldn't mess around... I'd just lance the centre of the seized pin out with a cutting torch

ding ding ding........we have a winner !!!

 

[Grader4me]

Yeah,I tried the pipewrench method with a 3' pipe breaker bar.Nada.
Haven't tried the heat/freeze process.Sounds worth a try.But I'd like to hear from someone who's actually chased this bear...and whupped it.Seems like a problem a lot of people with old equipment are going to run into.

I have seen pins that were seized in and the only way they would come out is with the heat and rapid cooling. In some cases we had to do this a few times in a row, but eventually it would free up the pin. :yup

 

[hotsacks]

Grader,what did you use for freezing the pin?
Inspired by Digdug,I used up a B tank yesterday putting heat to the thing.Had most of the area cherry red.Nothing moved.Kind of leaves you with that empty feeling.

 

[Grader4me]

Just sprayed it with cold water after it was cherry red. Keep in mind though...have your pin ready to come out...if it is mushroomed, you have to grind that down or something. Once the pin starts to come, you have to try and remove it as quickly as possible as it will stick again in a short period of time. Then you have to start the process all over again.

 

[hotsacks]

Well Grader,no acetylene until tomorrow but I'll be following your direction when I get the tank filled.Seems to me heating the casting would be better than heating the pin ends,yes? Anyone know the physics of what goes on when heat/cool is used? Are we breaking the rust bonds? I like to know these things when I'm playing with things worth 3 or 4 grand.
And thanks.

 

[Wulf]

I'm no expert in metallurgy but the steel pin, cylinder and bosses would have been 'heat treated' during manufacturing in that the temperature and rate of cooling would have been controlled to ensure the steel and its additives crystalised properly.

The pin and the other components also probably went through additional treatment to provide strength, resistance to fatigue and wear properties, this may include quenching in a controlled environment

IMO...continuing to overheat and cool the components with a torch and quenching with water or fire extinguisher may damage the components and may result in deformation or even cracks... it may also be OK but you will use a lot of time, gas and frustration and you maye end up lancing the pin out anyway.

 

[Squizzy246B]

Hotsacks, Your getting a lot of "site unseen" advice. Wulf is right and it all depends on the actual arrangement...wether its cast steel or fabricated etc etc. As stated before a pic would really help a lot. A portable hydraulic press can apply hundreds of tonnes pressure and will be the safest option. Cutting may be the go depending on the arrangement. Is it the free end of the ram or the cyclinder end?

 

[Grader4me]

These guys are right..I am only telling you what worked for us. It will be your decision on what to do on your machine.

 

[hotsacks]

Squizzy,I apologize for the lack of pictures but I don't have a digital camera.Wulf makes a good point.The bosses are cast steel and would have been spec'd to death in manufacture.But I would have to lay off cutting the pin out to a mobile welder @a quoted C$300. Add that to the cylinder repair bill and I've exceeded my budget for backhoe repair for the next long while.
Besides,there's pride involved here.It's a shadetree thing.
You're right though.A lot of good advice here.Keep it coming.These boards help us all.