AC high pressure line crack

About a month ago my AC hard line in front of the motor right next to the pressure sensor developed a very large crack. It literally broke in half. My guess is it developed a crack due to vibration with the 2 semi-solid motor mounts and 230k miles of hard driving.
Checked everywhere and nobody makes a replacement part and no NOS parts available.

Luckily, i work in a facility that has greatly skilled welders.
Took it in and had someone TIG weld it in 2 passes. I then FPI'd it (penetrate inspection) with our NDT level 3 inspector. No issues with the weld.

Took the line home, installed and AC ran great.

Last week i lost all R134A and saw a small crack developing in the middle of the weld.

My question is; can this line not be welded? It would appear the crack is from stress, same as the first time. Can i wrap it with rubber hose to help insulate from thermal and vibration?

He did not do an argon purge and i only did a acetone clean and light scrub with a brush to clean the crack before welding. Really didnt think that was going to crack again, but it looks like the weld bead is structurally weaker than the parent material.

Other options for repair?

So far plan is to route out the weld bead, clean, argon purge, re-weld, FPI and UT test for penetration. Then wrap the weld with either rubber hose or maybe even JB weld to prevent future cracking

Damn. Sucks that it's on the bend. Yukons have a bad habit of rubbing through the rear A/C lines under the car. We have repair sleeves that we use. The line gets cut, and the sleeve gets crimped (with a special tool) and then soldered, much like indoor plumbing.

Besides what Abaddon said, maybe check around some junkyards/Morad for one? I can't imagine it being unique to just our cars...

My guess is metal fatigue, can you replace the line assembly?

Mr.Riviera wrote:

About a month ago my AC hard line in front of the motor right next to the pressure sensor developed a very large crack. It literally broke in half. My guess is it developed a crack due to vibration with the 2 semi-solid motor mounts and 230k miles of hard driving.
Checked everywhere and nobody makes a replacement part and no NOS parts available.

Luckily, i work in a facility that has greatly skilled welders.
Took it in and had someone TIG weld it in 2 passes. I then FPI'd it (penetrate inspection) with our NDT level 3 inspector. No issues with the weld.

Took the line home, installed and AC ran great.

Last week i lost all R134A and saw a small crack developing in the middle of the weld.

My question is; can this line not be welded? It would appear the crack is from stress, same as the first time. Can i wrap it with rubber hose to help insulate from thermal and vibration?

He did not do an argon purge and i only did a acetone clean and light scrub with a brush to clean the crack before welding. Really didnt think that was going to crack again, but it looks like the weld bead is structurally weaker than the parent material.

Other options for repair?

So far plan is to route out the weld bead, clean, argon purge, re-weld, FPI and UT test for penetration. Then wrap the weld with either rubber hose or maybe even JB weld to prevent future cracking

The line is unavailable.
This is the fix i went with.

And its broke again. Im assuming the same spot but ill check tonight.
Really not sure WTF to do with it now. its 102° out down here

This time it has a pinhole leak in the same hose, different area. Another trip to the shop for TIG welding prob wont fix it for long.

Anyone have a parts riv with this hose still on it??