We currently have a bad wheelspace thermocouple on our GE7FA 1st stage inner wheel space temp probe (the -2). As no one in our group has experience replacing this exact one, we are wondering how involved or tedious is removal and installation. I know it bends quite a bit in its tube. Any info could help.

Thanks.

 

In spite of their length, removing the old thermocouple hasn't been difficult, especially when the TC is broken into 2 pieces. Unfortunately, this has always been the failure mode on these particular TCs on our 7FAs. The tube fails and takes the TC with it. Removal of the broken section & replacement of the guide tube then requires upper casing removal. However, you may be lucky and have a bad (but physically intact) TC.

Assuming the old one is intact, stretch the new & old TC's out side by side to ensure they're the same length. Mark the position of the Swagelock fitting from the old TC onto the new TC so you know when you're close to home. Getting the TC started into the passageway is the tricky part. It's possible (if not likely) you'll get it started & insterted a ways without actually being in the passageway. It's hard to push it in when you miss the passage. It should go in with little force initially, and get harder as it goes in further but never so hard as to bend it out of shape. It does bottom out against a protruding tip, so don't worry about it rubbing against the wheel. It takes patience, trial & error. Good luck.