B21TLB Replacing oil cooler return pipe

[nyone]

I would try to weld a patch on the line while it was still in the machine. It's a low pressure line so something like JB weld may possibly even work just fine.

I have tig welded high pressure hydraulic lines before. It took a few hours to chaise pin holes but the replacement piece was connected to a $1000 cylinder. That unit hasn't leaked in 5yrs and i still own it.

 

[kubotaswede]

After dividing the return pipe it easily came off the tractor. Mostly superficial corrosion but one quite large hole (2 mm) in a corrosion pit on the underside of the pipe (see photo). I have bought a new pipe to bend and a compression union. The structure is quite complex (see photo) so I am not sure I can get the bends right. Would it possible to repair the leak with a small MIG weld on this low pressure pipe? Or should I go for trying to bend the new one?

 

[Smokeydog]

Welding depends on the welder and condition of the pipe you can’t see. I once welded a pin hole leak on a Kubota B20 hard line for the power steering circuit on the tractor. Thought it would be a temporary fix but was permanent over 10 years till I sold the tractor. I have more luck than skill.

Had the B20 for over twenty years and B26 since 2016. Excellent machines for our small hillside farm.

 

[rScotty]

I've done a lot of similar repairs working as a tinker in the third world. All done with oxy/acetylene.
I wouldn't weld it, I would carefully form a patch out of tube material that covers about half the diameter of the pipe. Then use silver-braze for strength and flowability to braze the patch over that whole area.
If it is beyond your ability, I am sure there is an old torch welder in your area that can do it. All it takes is patience and a good hand with the flame.
rScotty

 

[kubotaswede]

Thank you rScotty. This is far beyond my ability. But the good news is that I managed to bend a replacement pipe for the foremost half which fits quite well and connects to the rear half with a compression union. I am now replacing the hydraulic oil and the filters. The hydraulic filter was not easy to find in the EU but I hope it arrives this week. Then I can test for leaks and hopefully the tractor is up for use after that. I thank the forum for interest and good advice in my problem. It has helped me to maintain confidence during the repair process. Thank you all!
Lars