Sierra Fuel Filler And Breather

[peter_m7uk]

I will shortly be installing the fuel tank and filler on my Lightweight and I was

thinking about a breather system, but not really sure what to do. I kept

the filler and all the attached bits from my Sierra, as you can see in this

pic: fuel filler system .

 

My question is how it all works?! Obviously the large diameter pipe goes straight

from the cap down into the tank, but there seems to be a second smaller pipe

which would have gone to the tank. Presumably this lets air out when you fill

at the pump? But what are the 2 bits attached to the side of the large pipe and

the other hoses. Some sort of valve and air flow arrangement, but what do they

do and how?

 

Hope someone can help

 

Pete

[Guest gdc]

hi pete

what engine are you fitting ?

carbs?

injection?

ect

further info rqd .

re your bits i assume as described vent ect other bits i dont know

are you using the kneck cos its there or do you need further info to assertain the need for the bits on the kneck

graham

[peter_m7uk]

My engine is a 2.0EFi Pinto and the donor was a 1989 Ghia model.

 

Just wanted to know how the breather works for general info - I'm not

reusing the Sierra one. Also so I can plan a breather for the Lightweight.

 

Cheers,

 

Pete

[Guest paul thompson]

Hi,

The large dia pipe is obviously the fill tube, attached to this is a smaller but still large dia pipe, this is the sensor tube which stops the gun from overfilling the tank. when Air cannot escape because the sensor tube is covered with fuel, the fuel fills up the filler and the gun cuts off. The sensor tube is fixed to the top of teh filler. The small dia tube is a general breather, and is connected to a rollover valve. This prevents the fuel from leaking out of the breather in the event of .... wait for it... a rollover, and this just vents to atmosphere after the rollover valve.

There you have it in a nutshell.

These days you are not allowed to vent to atmosphere as it won't meet the Carbon emmission legislation. As a self builder, you fortunately are not required to meet this legislation, only if you want type approval.

These days, the vent needs to go into the engine via a vapour management valve controlled by the ECU.