THOMASPIN
Airhead
After 43 years my gas cap started leaking when full, only ceasing to do so once 2 gallons had been used.
Time for a new gas cap cork seal - p/n 16 11 1 230 603.
The pivot pin is serrated and only comes off to the left, using a pin punch:
Vise grips depress the seal against the strong spring to expose the retaining rivet:
A Dremel abrasive wheel is used to grind off the rivet head, taking care not to remove any of the post material:
Dismantled - old seal - shot, spring and rubber spacer on shaft:
The tricky bit. You need to drill a 0.17” (#17 drill size) hole dead center and perpendicular. I locked the cap in place in the wooden jaws of the vise, checking that the rim was equidistant either side from the surface using a dial caliper as a depth gauge, then clamped this simple right angle drilling jig to the bench after centering. I started with an oversize drill to establish a centered cone cut (a small drill bit is too prone to wandering), then switched to the #17. Sadly I sold my drill press years ago which would have made this easy:
The drilled hole is tapped for an M6 x 1.0mm bolt, which is 0.23” in thread diameter (I’m mixing metric and English!):
The tapped bore. I used WD40 as cutting lubricant:
Ready for reassembly - rubber collar, spring, washer, lock washer and stainless steel M6 bolt, after blasting everything with compressed air. Blue Loctite is used on the threads:
Job completed - note the vent hole to relieve tank gas pressure - orientation is irrelevant:
The first seal lasted 43 years so I will be replacing this one when I am 110.
T.
Time for a new gas cap cork seal - p/n 16 11 1 230 603.
The pivot pin is serrated and only comes off to the left, using a pin punch:
Vise grips depress the seal against the strong spring to expose the retaining rivet:
A Dremel abrasive wheel is used to grind off the rivet head, taking care not to remove any of the post material:
Dismantled - old seal - shot, spring and rubber spacer on shaft:
The tricky bit. You need to drill a 0.17” (#17 drill size) hole dead center and perpendicular. I locked the cap in place in the wooden jaws of the vise, checking that the rim was equidistant either side from the surface using a dial caliper as a depth gauge, then clamped this simple right angle drilling jig to the bench after centering. I started with an oversize drill to establish a centered cone cut (a small drill bit is too prone to wandering), then switched to the #17. Sadly I sold my drill press years ago which would have made this easy:
The drilled hole is tapped for an M6 x 1.0mm bolt, which is 0.23” in thread diameter (I’m mixing metric and English!):
The tapped bore. I used WD40 as cutting lubricant:
Ready for reassembly - rubber collar, spring, washer, lock washer and stainless steel M6 bolt, after blasting everything with compressed air. Blue Loctite is used on the threads:
Job completed - note the vent hole to relieve tank gas pressure - orientation is irrelevant:
The first seal lasted 43 years so I will be replacing this one when I am 110.
T.
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