Sub Tank - "Losing Fuel"??

[Tony]

Hey it's me again!! Howzit everyone - Here's an odd one, if I fill up both tanks, and I don't use the sub tank, when filling up the main tank - (and this happens every time) I always open up the sub's cap to check the level, and when I see no diesel, I always tell the jockey to fill it to the brim again. I end up putting anyting up to two litres into a previously full (to the brim) tank. There is never any smell or evidence of leaking, it just seems to vanish! Any ideas??

[Stefan]

What distance are you getting on "both" tanks?

[JoshJ]

Hi Tony,

It says in the manual that you get with the car on pg 2-23 that it automatically pumps feul from the sub to the main tank everytime you start the car.

Stefan, I get +- 850km in town on both tanks.

[JoshJ]

Forgot the important part. It pumps automatically for a few seconds everytime you start the car hence the 2liter shortage over a long time period.

[Kagiso II]

it is also very bad to fill a tank to the brim .. leaves no room for the fuel to expand under heat conditions .. ALSO .. you will loose fuesl at the overflow [I normally tell attendant to STOP when the pump auto stops ..]

[Tinus lotz]

I agree with josh every time you start you here the pumps kick in so you can loose a bit of feul to main tank

[ricster]

or possibly a siphon effect if the level of the main tank is lower than the sub tank. it may be the 2 litres that sits in the pipe from the tank to the top of the filler.....

[Herrie]

Ek stem saam hiermee!

Noudat my Patrol baie gebruik was toe ek my knie operasie gehad het en vir drie weke nie self mag bestuur nie is my subtenk al amper half en niemand het die subtenk se knoppie ge druk nie.

Ek maak die subtenk gereeld leeg as die maintenk half is net om seker te maak dat die subtenk nog behoorlik werk.

[JoshJ]

Harry ek doen ook so. Ek ry altyd al 2 leeg, so maak ek seker dat ek weet die sub is in n werkende toestand. Ek wil nie op 99 uitvind ek het n probleem nie.

[Tony]

Ok, that makes sense as I am certain that there are no leaks, also if it was coming out of the overflow pipe I would surely smell the diesel.
Stefan, I do on average about 900 km on both tanks - (650 - 700 on main & 250 odd on the sub)