How full is full?

[MagicalArmchair]

We have the two 150 litre tanks of water, and one 150 litre tank of diesel.

For fear of overfilling, I will go and whip the hose pipe out of the water tank at just over 3/4 on the gauge, robbing me of probably half a tank over all. How full do you fill your tanks? Stop at 3/4? Is there space 'above' the full on the gauges? Or do you just wait for it to pour out the filler? My fear being that it will leak out the top of the tanks, or out the breather with the diesel!

[JEN-et-ROSS]

We just keep filling until it overflows..Simple .......The gauges are really inaccurate, just use as a guide..........Bill

[MagicalArmchair]

Wow, exciting, no worries about it leaking out of the top of the tank where the hatch is? With three kids on board, we get through a whole lot of water, so a bit extra will go a long way  .

Same with fuel too? A bit like filling up your car??

[Symphony]

Just fill until water comes out of the overflow. From memory the forward tank vents into the chain locker and the aft one overboard. Be a bit more careful with fuel for obvious reasons, particularly filling with a hose as foaming makes the last few litres potentially messy. I fill from 20l cans of white from Tesco, usually 2 at a time to keep it above half full on the gauge. Half a tank (75l) gives 35+ hours or around 200 miles - more than enough for my pottering. When doing long passages like my trip across the Med, much of it motoring, I counted the hours running time and topped up based on 2l an hour with 2 * 20l cans as reserve,

[AFRiCA]

If you live in a climate with generally high humidity you may find that having the fuel tanks full most of the time will reduce the possibility of moisture forming inside the tank and the resultant problems associated with a water and fuel mix.

[Yngmar]

Water tanks until they overflow. Fuel tanks until the gurgling in the vent indicates they're about to, as you don't want those to overflow.

If you have a leak at the tank fittings, fix it! They will leak even with a half full tank when the boat heels and rolls and the tank contents begin to slosh around.

[Salty]

We just keep filling until it overflows..Simple .......The gauges are really inaccurate, just use as a guide..........Bill

Like others who have replied similarly, I also wish to join the queue of saying “Me too.” (Then sometimes I take a quick look for any leaks).🙈
The fuel tank gets stopped when the filler pipe starts to gurgle.

[Rampage]

Full to overflowing as well!  I put a wodge of kitchen paper under the fuel vent, listen for the “I’m full” gurgle and hopefully stop just before the vent is sick. 
Man who sells fuel from his mini tanker in Sammi has the gurgle method down to a fine art: he leaps on board with his hose, fills the tanks whilst crouched over the filler.  A real piece of street art and he really does get the tank full: he wants to sell you that extra litre or two!

[Noelio Abrunhosa]

 hi. on my filling hose i have a water meter. normally run 1 tank dry, swop to 2nd tank, then fill with exact 150 litres.
regards
Abby

[Jeffatoms]

Somewhat on/off topic but we keep our diesel tank topped off.  The gauge is wonky and not very accurate.  We my have filled too much last time as during our pre-ouring check I found clean about 2 cups of fuel under the oil pan.  NOT GOOD is it indicates  fuel leak somewhere.  This has never happened before and my current theory is it back flowed thru the diesel-to-fuel tank return line by way of sloshing in the tank.  We had a diesel mechanic try to trace it to the source and he concluded it was gear oil but could not identify the source on our MD22L, not diesel because it didnt have the diesel smell.  I disagreed.

As with all leaks, I try to find the definitive cause by setting up little mouse traps with isolated paper towel squares. I'll get it but I will not be stopping off with fuel up the fill hose until I do.

[geoff]

On my md22l I had an engine oil leak from the front of the engine. It dripped  from the base of the cam belt cover. After one false start it was cured by a new oil pump which on the md22 is external and reasonably easy to change once the cambelt is off. Geoff

[MagicalArmchair]

What a revelation. With three kids and the wife now celebrating the fact we have a shower on board, we would get through both tanks when I filled them to 3/4 on the gauges in a day of washing up, drinking tea, washing and showering. We went to Yarmouth yesterday and stayed on the moorings all day, going to the beach, coming back (bringing most of the beach on board with us), showering, cooking, drinking, washing, washing up, and we only used one, full (now completely full!) tank.

Perfect. Thanks for the assistance.

Good luck Jeff with the fuel leak hunt!