Hydraulic Leak on KH66 Excavator - How to repair?

[Woody3]

My KH66 has a couple of leaks. One serious and t'other not so.

The worst of the two is on the elbow of the metal pipework on the boom, as pictured below:


URL of the original image: http://i785.photobucket.com/albums/yy139/Woody3_photos/DSCN6641.jpg


URL of the original image: http://i785.photobucket.com/albums/yy139/Woody3_photos/DSCN6643.jpg

It is this weld that has the airline crack:


URL of the original image: http://i785.photobucket.com/albums/yy139/Woody3_photos/DSCN6642.jpg

Is this possible to weld?

[martyn williams]

Looks like a bad old repair job,best way is to take the ram off, take out the rod,clean all the oil off it, remove all the old weld and start again.
Its very important to have a good clean bit of metal with no oil contamination or paint.I have electric welded these in the past but brazing will do a good job.I would renew the metal pipe if you can get hold of some if it corroded or damaged .A straight forward job, but the key to this repair job is to have a good clean pipe end and elbow.As its a small ram it will be easy to do on a workbench and make a good job of it.
Martyn

[Woody3]

Thanks for your reply Martyn.

I've only had the excavator about 6 weeks, so everything is new to me at the moment.

Is the ram easy to remove? I've just been outside to get a grasp of the work involved and have come up with this step by step method (couldn't find a "how to" on the Internet!)

> rest bucket lightly on the floor, in this position:


URL of the original image: http://4.bp.blogspot.com/-lL5Oqot6bUk/TcVRRZIs4SI/AAAAAAAAABA/vsCcEWxwZ34/s1600/Excavator.jpg

> secure the boom in place. I think I'm going to ratchet strap it to a beam in my workshop, so it won't move.

> disconnect hydraulic pipe and drain fluid into container

> undo nut and bolt holding pin in at the top of the ram. Remove pin

> knock pin out at bottom of ram

> remove ram

Does this sound ok to you?

[FOWLER MAN]

Hi Woody,
Sounds OK to me.
The elbow and pipe in your Pics. have already been brazed.
It will be necessary to remove every trace of that braze if you are to weld it. This could be difficult to achieve.
It may be simpler to braze it again.
Make sure that the ram is empty and closed not to heat and dammage the piston seals.
It will be sufficient just to melt the existing braze till it drops off and re-make the joint, the heat should burn off any oil residue so you wont have too be too fussy about cleaning it. (just wire brush). I find the plain brass rods and separate flux better than the all in ine fluxed rods as they are more controlable.
Turn the ram to braze down hand as you go, or the braze will drop away.
Fred

[martyn williams]

The most important thing is to make sure that the boom is secure and cannot fall before carrying out any work on the ram.Then release any pressure in the ram by moving the lever.
Martyn

[FOWLER MAN]

The most important thing is to make sure that the boom is secure and cannot fall before carrying out any work on the ram.Then release any pressure in the ram by moving the lever.
Martyn

Yes, but theres no need to attatch it to a beam. If you keep the arm vertical and rest it on the floor the boom can't drop or move anywhere.
Fred

[martyn williams]

What I used to do is to is keep it vertical as Fred says but also have the back of the bucket against a solid object like a wall or other machine.Yours is only a small size machine so its not a problem.Good luck with the repair and be safe.
Martyn

[Woody3]

Well, it took me all of 5 mins to get the ram off. I was expecting it to be a big job, whoops.

I've stuck an acro prop under the boom for added security!

All I've got to do now is find someone to fix it for me...

I've been advised on the following options:

1) Cut pipe and elbow off and tig weld new hydraulic nipple?/union? in place and put a 90 degree bend on the hydraulic pipe

2) Remove existing brazing and rebraze

3) Remove existing brazing and tig weld

What are your thoughts?

[essexpete]

If you get it too hot you might damage the gland seal.

[philwheelton]

there are some hydraulic firms that will replace the pipe and pressure test it fairly cheap