Need vented gas cap?

[Bock62]

My recently-acquired 3000 MKII has a gas cap that appears is not vented -- is a vented cap needed for our cars?

 

[AUSMHLY]

Yes. The caps should have a small pin hole underside.

 

[BabaKahawa]

My healey came with a non vented fuel cap also.
I reworked the thin metal pressure wings behind the rubber gasket so the cap still closed properly, but was loose enough to vent the tank. It worked and the cap has not come off or makes noise.
I have also heard others who drilled a small hole through the cap to vent the tank.
Good luck.

 

[DerekJ]

Absolutely. I had a non-vented replacement cap before I understood the system. On a long road trip the fuel pump would eventually act like it was sucking air. Every 100 miles or so I would stop and tighten everything but, coincidently I always stopped at service stations, at which time also I took the opportunity to top up with petrol.

The refuelling allowed air back into the sytem and off I went blindly thinking that my frantic tightening had done the trick!

BTW that cap was purchased from a supplier of AH parts. They should know better than to sell these things.

 

[Bob_Spidell]

If you still have the original tank, there will be enough pinholes in the tank for venting :wink:

 

[bob hughes]

My cap is original - no vents and I don't have any problems.

Probably due then to the rubber connection between tank and filler tube as the tank has been replaced at some time with a aluminium one (No pin holes I hope)and when I fill her up there is a strong smell of petrol ( gas) in the boot - ( trunk) for a while.

Bob

 

[tahoe healey]

There is a great picture of an original cap in this month Healey mag. I don't remember which one.

 

[Bock62]

Thanks for all the help! -- When I fill the tank is also strong smell of petrol in the boot for a while.
Since have had no other issues, will assume was 'chasing a ghost" and leave it as is...

 

[Randy Forbes]

I've seen a lot of cars that seep gasoline around the sending unit when freshly filled. Look for stains...

Besides the gasket, there's supposed to be copper sealing washers under the six (6) mounting screws.

 

[Bock62]

Thanks -- I'll check it again......