F-hose

Part No: 078 133 784 AJ

Number 28 here:

Notes

Part number 078-133-784BG is listed for the AZB, and is probably not an F-hose.

Note that when replacing the F-hose, the coupler (number 29, part number 078-133-587) is very brittle and might break.

Fortunately, it is NOT a check valve, only a coupler, and can be replaced by random parts and some teflon tape.