Post by ronnie27478 on May 26, 2020 10:28:09 GMT -9
This is in regard to the switch assembly under the fuel selector levers that select which tank the gauges are monitoring. From the IPC,
Plate Assembly - Fuel Control Switch Piper PN 52220-0 and the associated limit switches, Piper PN 487 807, AKA MS25253-1 (microswitches).
I found the left outboard switch bad and pulled the assembly to replace it. While it was out, I decided to replace the other three switches as well as a preventative measure. I was very careful to put the new switches in the exact same position as the old ones (marked the position before removing them) and changed one switch at a time so as to make sure I put it back together just as it cam out. When I put it back in and tightened up the mounting screws, including replacing some missing ones, I was shocked to find the switches did not engage as the fuel selector was moved. After lots and lots of time of removing, adjusting, repeat, etc, etc, etc, I finally got all working except the one for the left inboard tank. I've finally discovered that the phenolic board the switches are mounted on bows downward when all the mounting screw are tightened to the point that the actuator rides up and on top of the left inboard switch. I now believe this was the reason for the missing mounting screws; to limited the amount of bowing in the board.
I have done this without removing the roll pins on the fuel selectors and cross feed control and removing the top metal cover. Rather, I was able to remove and replace the assembly via the opening in the right side of the pedestal.
Does anyone have any experience with this they can share? Have you run into an issue with the mounting board bowing? What is the best method to adjust the position of the switches? The inboard ones seem so very critical in their placement; too far out and they are not engaged by the actuator; too far in and the actuator hits the switch or rides up over it. This seem like a very poor design and I'm quite frustrated with the amount of time and effort this has consumed so far. Any pointers would be greatly appreciated.
Thanks,
Ronnie
Plate Assembly - Fuel Control Switch Piper PN 52220-0 and the associated limit switches, Piper PN 487 807, AKA MS25253-1 (microswitches).
I found the left outboard switch bad and pulled the assembly to replace it. While it was out, I decided to replace the other three switches as well as a preventative measure. I was very careful to put the new switches in the exact same position as the old ones (marked the position before removing them) and changed one switch at a time so as to make sure I put it back together just as it cam out. When I put it back in and tightened up the mounting screws, including replacing some missing ones, I was shocked to find the switches did not engage as the fuel selector was moved. After lots and lots of time of removing, adjusting, repeat, etc, etc, etc, I finally got all working except the one for the left inboard tank. I've finally discovered that the phenolic board the switches are mounted on bows downward when all the mounting screw are tightened to the point that the actuator rides up and on top of the left inboard switch. I now believe this was the reason for the missing mounting screws; to limited the amount of bowing in the board.
I have done this without removing the roll pins on the fuel selectors and cross feed control and removing the top metal cover. Rather, I was able to remove and replace the assembly via the opening in the right side of the pedestal.
Does anyone have any experience with this they can share? Have you run into an issue with the mounting board bowing? What is the best method to adjust the position of the switches? The inboard ones seem so very critical in their placement; too far out and they are not engaged by the actuator; too far in and the actuator hits the switch or rides up over it. This seem like a very poor design and I'm quite frustrated with the amount of time and effort this has consumed so far. Any pointers would be greatly appreciated.
Thanks,
Ronnie