Bobcat 743B lift Cylinder Help

[MikeLawrence]

I have a BC 743b and one of the lift arms is leaking oil at the connector at the front of the cylinder. It is close to the cylinder wall where the connector appears to be welded to the cylinder.

Both cylinders are mounted with the connectors pointed down toward the ground. The one leaking appears to be bent probably from something getting between it and the frame.

The pics I see of 743b's show the cylinders mounted with the connectors upwards. Can they be mounted either way?

Is that connector welded in?

Can it be welded if I remove all the guts first?

Or do I have to buy an new cylinder?

Thanks for any help.

Mike

 

[Chris 8603]

Mine are mounted upward on a 743. It really doesn't matter which way for it to operate correctly. The fittings are welded onto the cylinder barrel, a good tig welder could most likely weld up the fitting. I have had some others done in the past with good luck. Like you said just remove the seals and packing.
Good luck

 

[brdgbldr]

Here is a great video of a cylinder repair:

 

[MikeLawrence]

Mine are mounted upward on a 743. It really doesn't matter which way for it to operate correctly. The fittings are welded onto the cylinder barrel, a good tig welder could most likely weld up the fitting. I have had some others done in the past with good luck. Like you said just remove the seals and packing.
Good luck

Thanks Chris,

With the connectors pointed down, there is only about an inch of clearance between the connector and the frame. So being bent to the side slightly was probably due to something getting between.

Maybe at some point, they began installing them with the connectors on the topside...

I have a stick and mig welder, but not sure I want to try.

Wouldn't happen to have a good one for sale?

 

[laurencen]

you can weld it up with a mig welder, trick is clean and no oil in the crack, slightly groove the crack, test the welder on scrap to get a clean clean weld and go for it, worst that can happen it leaks again and try again, I would rotate the cylinders facing upward

 

[Chris 8603]

Thanks Chris,

With the connectors pointed down, there is only about an inch of clearance between the connector and the frame. So being bent to the side slightly was probably due to something getting between.

Maybe at some point, they began installing them with the connectors on the topside...

I have a stick and mig welder, but not sure I want to try.

Wouldn't happen to have a good one for sale?

No sir I don't. If you were here closer I would help you weld it.

 

[wings5j]

I have a BC 743b and one of the lift arms is leaking oil at the connector at the front of the cylinder. It is close to the cylinder wall where the connector appears to be welded to the cylinder.

Both cylinders are mounted with the connectors pointed down toward the ground. The one leaking appears to be bent probably from something getting between it and the frame.

The pics I see of 743b's show the cylinders mounted with the connectors upwards. Can they be mounted either way?

Is that connector welded in?

Can it be welded if I remove all the guts first?

Or do I have to buy an new cylinder?

Thanks for any help.

Mike

Mike,

Fittings down I believe is normal. If you need more clearance, I would check the spot where the lift arms rest on the frame. After years of use this area can get worn and needs built back up.

If the fitting attach point that is leaking is the one furthest away from the push rod end, you can probably get away with welding it without disassembling the cylinder. Once you have removed the cylinder, just fully extend the rod to get the piston as far away as you can.

Good luck,

John

 

[Markle]

Mine are down. i think the rear grease zerk access might be different if the cylinder was rotated.

 

[Chris 8603]

You definitely need to check your lift arm stop. Yours is going down way to far down. That's why it's bent the tube.

 

[miketurner]

Chris, that's good to know about the mounting orientation not being a big deal for function. I've been leaning toward trying to weld it myself, but you're right- removing the seals and packing is key. Have you noticed any performance issues when reusing a cylinder after welding? Always worried about sealing it properly again

 

[stevemurphy]

Appreciate the video recommendation! I'll check it out for some tips. Did you ever have to deal with a bent fitting like this? If so, curious if you think it's worth trying to bend it back into shape before welding or if that's just asking for trouble.

 

[laurencen]

Appreciate the video recommendation! I'll check it out for some tips. Did you ever have to deal with a bent fitting like this? If so, curious if you think it's worth trying to bend it back into shape before welding or if that's just asking for trouble.

could you post a picture of the fitting where its leaking, mine face downward, over the years I have welded fittings and bushings to cylinders, always used the mig, you have to clean well and grind the crack some to ensure good penetration

you could likely weld this up on the machine, raise arms block and remove pin, pull the cylinder end and seal off, piston far away from where its welding and go for it

 

[stevemurphy]

could you post a picture of the fitting where its leaking, mine face downward, over the years I have welded fittings and bushings to cylinders, always used the mig, you have to clean well and grind the crack some to ensure good penetration

you could likely weld this up on the machine, raise arms block and remove pin, pull the cylinder end and seal off, piston far away from where its welding and go for it

Hello, I don't quite understand you.

 

[laurencen]

the welding part of posting a picture of the fitting you are having issues with

 

[stevemurphy]

I don't have any issues with fitting, maybe I wrote not so-clear

 

[laurencen]

you have a leak close to the cylinder wall and said it was bent, Im assuming the bushing welded to the cylinder the connector screws into is bent and cracked at the weld, picture of the said connector and cylinder would give a better idea what was going on