Outer Limits 4x4 Board

I have a 75L LRA belly tank in my petrol GQ (15 years old). I pulled the tank out yesterday to check the pump and the filter sock was totally clogged with rust (none in engine bay filter).

I drained and flushed the tank and scooped out around 1/2 a cup of very fine rust powder.

Now i'm pretty happy with how clean the tank is but how do i stop this from happening again? The tank seems sealed as it always has a build up of pressure when i open the fuel cap.

James

POR 15 make a product for this purpose. I have not used it personally but a friend used it in his boat and it worked well.

Keeping the tank full will stop it rusting....

x2 for por15 used it in my bike tank worked a treat.

I would use a product from KBS coatings to stop rust in the tank. Aust. made and fast delivery also.
check there web out here

http://www.kbs-coatings.com.au/Tank-Sea ... 0-1-0.html

want33s wrote:Keeping the tank full will stop it rusting....

Only if there's no water in the bottom. Some people use a bottle of meths in the tank to emulsify any water and run it through the engine, but I've never tried it.

Don't use ethanol blend fuel in steel tanks. Ethanol attracts any water that may be around, including atmospheric moisture (humidity).

DAMKIA wrote:Don't use ethanol blend fuel in steel tanks. Ethanol attracts any water that may be around, including atmospheric moisture (humidity).

Unless your tank is open to the air, that moisture is in there anyway.

KiwiBacon wrote:

DAMKIA wrote:Don't use ethanol blend fuel in steel tanks. Ethanol attracts any water that may be around, including atmospheric moisture (humidity).

Unless your tank is open to the air, that moisture is in there anyway.

Tanks with emission controls have a valve that allows air into the tank to prevent the tank collapsing. The difference with emissional compliant tanks is they vent positive pressure into a carbon canister rather than simply venting to the atmosphere.

This is why there is almost always POSITIVE pressure in a tank when you open it.

DAMKIA wrote:Tanks with emission controls have a valve that allows air into the tank to prevent the tank collapsing. The difference with emissional compliant tanks is they vent positive pressure into a carbon canister rather than simply venting to the atmosphere.

This is why there is almost always POSITIVE pressure in a tank when you open it.

The tanks on my vehicles always have negative pressure (i.e. a bit of a vacuum) in them when opened.

KiwiBacon wrote:

DAMKIA wrote:Tanks with emission controls have a valve that allows air into the tank to prevent the tank collapsing. The difference with emissional compliant tanks is they vent positive pressure into a carbon canister rather than simply venting to the atmosphere.

This is why there is almost always POSITIVE pressure in a tank when you open it.

The tanks on my vehicles always have negative pressure (i.e. a bit of a vacuum) in them when opened.

Depends how long it is left. If you pull up to refuel then the carbon canister will have been exposed to the vacuum of the inlet manifold, and you will get a bit of vacuum, but if the vehicle is left for an extended time the tank in fact generates a positive pressure from the volatile vapours (normally trapped in carbon canister) build up. Emission controls are there to prevent the discharge of these vapours to the air, venting the vapours to the inlet manifold from the carbon canister via a valve on vehicle start up.

There is a separate valve that allows air into the tank above a certain level of suction (negative pressure) to prevent the tank from crumbling as you use fuel volume, and it is usually in the fuelcap

DAMKIA wrote:Depends how long it is left. If you pull up to refuel then the carbon canister will have been exposed to the vacuum of the inlet manifold, and you will get a bit of vacuum, but if the vehicle is left for an extended time the tank in fact generates a positive pressure from the volatile vapours (normally trapped in carbon canister) build up. Emission controls are there to prevent the discharge of these vapours to the air, venting the vapours to the inlet manifold from the carbon canister via a valve on vehicle start up.

There is a separate valve that allows air into the tank above a certain level of suction (negative pressure) to prevent the tank from crumbling as you use fuel volume, and it is usually in the fuelcap

No inlet vacuum on these vehicles, they're turbo diesels. Likewise diesel has a rather low vapour pressure.

KiwiBacon wrote:

DAMKIA wrote:Depends how long it is left. If you pull up to refuel then the carbon canister will have been exposed to the vacuum of the inlet manifold, and you will get a bit of vacuum, but if the vehicle is left for an extended time the tank in fact generates a positive pressure from the volatile vapours (normally trapped in carbon canister) build up. Emission controls are there to prevent the discharge of these vapours to the air, venting the vapours to the inlet manifold from the carbon canister via a valve on vehicle start up.

There is a separate valve that allows air into the tank above a certain level of suction (negative pressure) to prevent the tank from crumbling as you use fuel volume, and it is usually in the fuelcap

No inlet vacuum on these vehicles, they're turbo diesels. Likewise diesel has a rather low vapour pressure.

OP was referring to a petrol GQ. Tank may have been from a diesel but it was filled with and plumbed (vented through the OE tank?) like a petrol if my reading of the situation is correct.

DAMKIA wrote:OP was referring to a petrol GQ. Tank may have been from a diesel but it was filled with and plumbed (vented through the OE tank?) like a petrol if my reading of the situation is correct.

We got sidetracked way back at the ethanol part.

KiwiBacon wrote:

DAMKIA wrote:OP was referring to a petrol GQ. Tank may have been from a diesel but it was filled with and plumbed (vented through the OE tank?) like a petrol if my reading of the situation is correct.

We got sidetracked way back at the ethanol part.

Do they add ethanol to diesel?

The ethanol comments are still valid pertaining to petrol, and given it was an old diesel tank it may not have had much in the way of rust protection when originally manufactured, compounding the problem. There is exposure to atmospheric air when the vacuum is released via the valve in the cap after the displacement (consumption) of fuel.

Part of the "ethanol proofing" of new vehicles is the reduction of fuel contact with steel/iron (usually substituted with aluminium alloy), as well as the necessary change in polymers used in hoses. Coincidentally this results in lighter components.

DAMKIA wrote:Do they add ethanol to diesel?

The ethanol comments are still valid pertaining to petrol, and given it was an old diesel tank it may not have had much in the way of rust protection when originally manufactured, compounding the problem. There is exposure to atmospheric air when the vacuum is released via the valve in the cap after the displacement (consumption) of fuel.

Not to my knowledge, but people have added meths to a diesel tank to acheive that same purpose (soak up moisture and remove it from the tank). I'm thinking that ethanol would continuously remove the moisture compared to it seperating out and staying in the bottom of the tank.

KiwiBacon wrote:

DAMKIA wrote:Do they add ethanol to diesel?

The ethanol comments are still valid pertaining to petrol, and given it was an old diesel tank it may not have had much in the way of rust protection when originally manufactured, compounding the problem. There is exposure to atmospheric air when the vacuum is released via the valve in the cap after the displacement (consumption) of fuel.

Not to my knowledge, but people have added meths to a diesel tank to acheive that same purpose (soak up moisture and remove it from the tank). I'm thinking that ethanol would continuously remove the moisture compared to it seperating out and staying in the bottom of the tank.

Ethanol/methanol/alcohols generally are hygroscopic, ie they attract water, so it both carries the water with it through the system (cleaning out existing water), but importantly actively attracts water in the first place from the atmosphere into the liquid fuel. This is why it is unwise to use eth blend fuels in small infrequently used motors (generators, mowers, brushcutters, etc)

This is also why it is recommended to do a fuel filter change at least once within the first few thousand km of commencing the use of ethanol blend fuels in vehicles. They wash all the crap out into the fuel filter often causing the vehicle to run like crap due to poor fuel flow.

I ended up just cleaning it out. I will try and run normal fuel and put some E10 once in a while to soak up any water. Probably a good idea to make use of the bung and flush it out yearly.

How do we get in contact with POR15, please?

Well 6 months later and my pump is cactus again! I will be cleaning and sealing the tank this time!


Does anyone know the size of the drain plug that is used in the LRA tanks? I missed placed mine today while draining the tank


James




PS: I hate removing the tank!!!!

Jimbo wrote: Does anyone know the size of the drain plug that is used in the LRA tanks? I missed placed mine today while draining the tank


James




PS: I hate removing the tank!!!!

Ya d1ckhead!!!

4 Ears wrote:How do we get in contact with POR15, please?

http://www.ppcco.com.au//kits3.htm" onclick="window.open(this.href);return false;

I have used the tank kit for a 40 series and it is great. I would stress that you read the directions well. (There is some info on the bottom of the above page to read before you buy)
I managed to make a mess all over the grass, hands and shoes so be prepared for the stuff to run out all tank orifices.
I also had some left over and did the filler neck as well.

A tip, if you clean off some of the outside of the tank back to bare metal, you can paint this too with the left overs. But you need to do the prep before you start anything as once the can of por15 is open it will go off in a few hours.

quickly pour out the amount of por15 you require then gladwrap and put the lid back on the paint tin and put it in the fridge... i had some in the fridge for 3 months and was still fine when i did the next project.

chunderlicious wrote:quickly pour out the amount of por15 you require then gladwrap and put the lid back on the paint tin and put it in the fridge... i had some in the fridge for 3 months and was still fine when i did the next project.

I had mixed success with this method. But if you give it a go and if it works its a bonus
Better to let it warm up after it has been in the fridge before you use it too

Pal wrote:I would use a product from KBS coatings to stop rust in the tank. Aust. made and fast delivery also.
check there web out here

http://www.kbs-coatings.com.au/Tank-Sea ... 0-1-0.html

This is what I'm using for my fuel tank. Have also used their Rust Seal. Great stuff but like all these types of products it can be a messy application and you go through heaps of disposable gloves keeping the stuff off your hands.