Filling the expansion tank?

[prc]

Re: cooler fueller

Originally posted by cheshire cat
This is a fair point, I assume that the pump (PD) is constant volume and therefore returns the surplus to either the filter, if cold or the tank when hot , via what I assume is the fuel cooler under the drivers side floor. The less fuel used and the hotter the weather the more churn and more cooling needed. There is obviously a large fuel temp gradient allowed for as volume is adjusted in relation to fuel temp(Foxy Mod) I hope that you Seat techs' will jump in and correct or expand any of this. I can say that on the hottest day we hade recently (28+C) on filling my ventectomied tank I could see hot vapour or steam coming out of the top right hand vent having just done several slow miles on a low tank (no light on) Am I right in thinking the valve on the fuel filter top is temp controled or is that done somewhere else. Hope I havn't hijacked the thread.

Yeah, but AFAIK the cooler is hooked to the fuel return line. I think it's there to cool down the high pressure fuel a bit (remember increasing pressure also increases the temp ). It's true that the volume is related to the fuel temp, but not only that .

Valve on filter top? I don't seem to remember this. Time to take another look in the engine bay.

 

[prc]

Originally posted by muddyboots
Slightly off topic, but related to fuel...
What would be the implications of running out of diesel?
Would it eventually start again after a refil, or would you have to mess about disconnecting pipes and priming etc ? I remember my dad running his Pug 305 van dry, and having to loosen some of the injector pipes to bleed air out while cranking the starter. Wouldn't fancy having to do that with the kind of fuel pressure PDs generate....

This is no longer necessary as the system is self priming (since early to mid 90's on most cars). It will take a bit to get started, make a ton of smoke, and will have a rough idle for a few minutes.

 

[deezal]

Originally posted by aceman
If you fill up until the nozzle clicks off and then depress the little lever on the right hand side of the filler with the nozzle you will be able to hear a hissing sound. This is the air trapped in the top of the tank being released. If you continue to hold the lever in I can get on average an extra £7-8 quid in which accounts for about 10 litres. Mind you as Paulo states be wary of not over doing it as the system is actually designed to deliberatly stop you filling all the way up so as to allow the fuel to expand in the tank

Everytime I fill the tank until near brim-full theres a hissing sound when screwing the cap on -must be the air trapped in the tank being released.

 

[g60jet]

ok, tell me more does the leon have this?

 

[stoneyfordNI]

yes , and as for the bit about PD pressure , dont forget that pressure is in the unit injector itself is it not , think its 2050 bar

 

[H & H 2.3]

Please can someone put a picture up of where you press with the nozzle to get this extra diesel in

 

[devonutopia]

Its at about 3 o'clock - Just rest the nozzle against this general area of the side of the mouth and you should hear a distinct hiss as the air releases.

 

[slimjim]

Everytime I fill the tank until near brim-full theres a hissing sound when screwing the cap on -must be the air trapped in the tank being released.

Yup... that is the cap pushing down the little black valve we are going on about.
If you fill up to the top, then put the filler cap back on, hear the hiss, take the cap off again and another 8-10l can fit in. Or just use the fuel pump nossle to push it in, as suggested

 

[andycupra]

is it really wise to be filling up the expansion part of the tank.

dont come crying to me when your tank bursts

 

[andycupra]

ok, tell me more does the leon have this?

yes, its at about 8 o'clock as you look down the pipe about 2 inches inside.

 

[slimjim]

is it really wise to be filling up the expansion part of the tank.

dont come crying to me when your tank bursts

I do sometimes vent and fill.. BUT ONLY if I know im going to be doing at least 40 miles or so as soon as I pull off the forecourt.

Even though people are saying it is safe, I wouldnt fill to the brim, vent, fill to the brim, vent, fill to the brim, then leave the car after half a mile, in the sun for two days....

IMHO that would be a daft thing to do. The vent IS there for a reason, to STOP you over filling. In my eyes if you are going to be using 30-40 miles worht of the fuel as soon as it it put in, the risk is neglegable.

Promise I won't come to you when my tank bursts

 

[cheshire cat]

is it really wise to be filling up the expansion part of the tank.

dont come crying to me when your tank bursts

I don't think they are designed (even in this day and age) down to the difference in the weight of 8-10 nlitres of diesel, any what Jim said was a good point to follow, long trips etc

 

[nomad]

is it really wise to be filling up the expansion part of the tank.

dont come crying to me when your tank bursts

I fill mine to the brim all the time all the time and had no probs yet !!

Hang on,.. what was that large bang from down in the office car park

 

[andycupra]

I don't think they are designed (even in this day and age) down to the difference in the weight of 8-10 nlitres of diesel, any what Jim said was a good point to follow, long trips etc

its not the weight...
its fact that petrol or diesel expands or contracts dependant on temperature!

you will know what i mean if you have ever filled up one of those green 5 litre petrol canisters for your mower, left it in the shed, thought one day "hey its sunny and a nice day ill cut the grass"..
you will be thinking:
now wheres that square shaped canister..
funny it was here the other day....
all i can find is this round one....

;-)

 

[slimjim]

now wheres that square shaped canister..
funny it was here the other day....
all i can find is this round one....

Good point... well made....

 

[cheshire cat]

well I don't have a diesel mower to compare, but diesel is just not as volatile as petrol

 

[andycupra]

well I don't have a diesel mower to compare, but diesel is just not as volatile as petrol

another good point made...

but it still applies!
so there

 

[R4nger]

Just a note...

http://www.killspills.org.uk

 

[Phil_beeza]

question - is it a Bad Idea having a (proper) plastic can of 5 litre in the boot?

 

[dmjw01]

question - is it a Bad Idea having a (proper) plastic can of 5 litre in the boot?

Depends how likely you are to run out of fuel!

Personally, I wouldn't keep a can of petrol in the boot because I'd be concerned about the fire hazard in the event of a serious rear-end shunt. The car's fuel tank is designed and positioned to minimise the risk of bursting in a crash, but the plastic can in the boot could easily burst. Diesel is much less of a fire hazard though.

http://www.killspills.org.uk

This is the principal reason why I don't vent when I fill. It may be slightly unlikely that you'll get spillage, but the consequences could be catastrophic for anyone coming along the road after you. None of us here really know for certain whether it increases the risk of spillage - but even if there's just a small risk then in my opinion it's not a risk worth taking just for the sake of an extra 100 miles of range.

I have first-hand experience of just how scary a diesel spill can be. One morning on my way to work I felt an unusual twitch of understeer on a corner I know well. I managed to correct it and was just thinking "that was a bit odd", when I went around the next corner and was confronted by a car coming towards me broadside-on in a four-wheel sideways skid. It stopped inches from me. If either of us had been on motorbikes we'd have been in real trouble.