Pressure in fuel tank

[GreaseMonkey]

I filled up yesterday and when I parked the car at home noticed a petrol smell.
Couldn't find any leaks, but when I opened the filler cap a fair quantity of petrol came gushing out.
This is on my Crayford converted 280SE wagon, so the tank is not standard, it is a custom made flat one under the floor, but presumably uses all the original pump/filter and accumulator etc although I can't see a breather anywhere.
I am guessing that when filling up, the petrol from the underground bowser tanks is cold, and as it was a hot day yesterday, it may just be expansion causing it to overflow, but is there any other way the tank could be getting pressurised?
Any thoughts appreciated.
Chris M.

 

[OzBenzHead]

Chris: I haven't yet made a direct visual comparison between my Crayford tank and a spare W108 tank I have, but I have read (somewhere? Crayview mag?) that the W116 Crayford used a W108 tank. If that's the case, I wonder what Crayford did about the breather / charcoal cannister arrangement that supposedly deals with fumes and pressure from the tank in a standard W108 installation.

When those items are cactus on a W108, there is a strong petrol odour whenever I add fuel; it takes quite some time to dissipate. On one 108 I changed the relevant hoses and the canister doover, and no more fumey pong.

Check your tank to see if it's a W108 part; if it is, check for the fume-gadget and see if it needs replacing / repairing.

Otherwise, I haven't a clue.

Here are the W108 workshop manual pages that illustrate the device I refer to.

 

[GreaseMonkey]

Thanks, if that's what it is, I'll get under and have a look.
Chris M.

 

[B13]

Did you fill it until the bowser clicked-off and stop, or did you pull the bowser hose out a bit and keep going until you can see petrol literally dripping out of the fuel filler?

Its tempting to do with the current price of petrol.

I.

 

[GreaseMonkey]

Did you fill it until the bowser clicked-off and stop, or did you pull the bowser hose out a bit and keep going until you can see petrol literally dripping out of the fuel filler?

Its tempting to do with the current price of petrol.

I.

The bowser shut off and it was below the filler opening, then I drove 6 or 7 kms home, so not overfilled.
C.M.

 

[BenzBoy]

I filled up yesterday and when I parked the car at home noticed a petrol smell.
Couldn't find any leaks, but when I opened the filler cap a fair quantity of petrol came gushing out.
This is on my Crayford converted 280SE wagon, so the tank is not standard, it is a custom made flat one under the floor, but presumably uses all the original pump/filter and accumulator etc although I can't see a breather anywhere.
I am guessing that when filling up, the petrol from the underground bowser tanks is cold, and as it was a hot day yesterday, it may just be expansion causing it to overflow, but is there any other way the tank could be getting pressurised?
Any thoughts appreciated.
Chris M.

Have you got a charcoal canister (or similar) that is blocked? Normally that way the excess pressure vents back through the motor. I know there is not one in OBH's schematic.
Regards,
Benz-Boy

 

[GreaseMonkey]

OBH mentioned that, I will have to get under and check.
C.M.

 

[OzBenzHead]

Have you got a charcoal canister (or similar) that is blocked? [...] I know there is not one in OBH's schematic.
Regards,
Benz-Boy

I thought it was item #35 in the diagram (1st graphic). There was a much larger charcoal canister in US-market versions. Item #35 is what I referred to as having replaced; I always thought it contained a charcoal element.

 

[BenzBoy]

I thought it was item #35 in the diagram (1st graphic). There was a much larger charcoal canister in US-market versions. Item #35 is what I referred to as having replaced; I always thought it contained a charcoal element.

Having scrounged for parts at wreckers in the past I have found that some have a kind of expansion tank and some later ones (more commonly) have the charcoal canister as was required under the ADRs. A blockage in whatever system the Crayford has would explain the blowback. My forint's worth.
Regards,
Benz-Boy

 

[GreaseMonkey]

Thanks for everyone's tips here.
I will get under and report back next week.
C.M.