Provincial
Well-known member
I am repairing my Case 580E backhoe. After 30 years the steel line to the hydraulic oil cooler developed a rust pit that leaked under the radiator. At first, I thought it was the $750 hydraulic pump, but I dodged the bullet!
The tube had a lot of rust pitting in the front end where dirt built up where it isn't accessible to pressure washing. The tubing wasn't painted or plated before assembly, and the factory paint job didn't reach that area. Since the rest of the tube was in good condition, I spliced a new section where it left the frame and crossed under the radiator. I did this to both the inlet and outlet tubes, and primed and painted them before assembly.
The tubes connect to the oil cooler using short 1/2" hoses and worm screw hose clamps. This is a low pressure return line, so Case kept it simple. The tubing is 5/8" outside diameter, and Case reduced it to 1/2" by brazing a short piece of 1/2" tubing inside. The smaller tubing has a bead formed near the end to help retain the hose.
I have a set of tools to form the beads in tubing, so I was able to duplicate the factory end. I found that the smaller tubing was a very loose fit in the larger tubing, and wanted to expand it enough to hold it in place while I brazed it, but also leave a gap for the brazing rod to flow into.
I used the beading tool to expand the other end of the small tube just enough to hold it firmly in place. This worked perfectly, allowing the brazing rod to flow into the gap between the two tubes.
Attached are photos of the small tube, the tools, and the assembled joint before brazing.
The tube had a lot of rust pitting in the front end where dirt built up where it isn't accessible to pressure washing. The tubing wasn't painted or plated before assembly, and the factory paint job didn't reach that area. Since the rest of the tube was in good condition, I spliced a new section where it left the frame and crossed under the radiator. I did this to both the inlet and outlet tubes, and primed and painted them before assembly.
The tubes connect to the oil cooler using short 1/2" hoses and worm screw hose clamps. This is a low pressure return line, so Case kept it simple. The tubing is 5/8" outside diameter, and Case reduced it to 1/2" by brazing a short piece of 1/2" tubing inside. The smaller tubing has a bead formed near the end to help retain the hose.
I have a set of tools to form the beads in tubing, so I was able to duplicate the factory end. I found that the smaller tubing was a very loose fit in the larger tubing, and wanted to expand it enough to hold it in place while I brazed it, but also leave a gap for the brazing rod to flow into.
I used the beading tool to expand the other end of the small tube just enough to hold it firmly in place. This worked perfectly, allowing the brazing rod to flow into the gap between the two tubes.
Attached are photos of the small tube, the tools, and the assembled joint before brazing.
