Diesel & Gas Transfer Pump - Cross Contamination?

[MTBob]

I'm building a "proper" transfer pump that will be used for diesel and gas. After filling my yard implements with gas, and then filling my tractor with diesel, am I likely to get too much residual gas in the diesel when I change to that fuel - or vice versa? I'm planning on holding the discharge line high enough to gravity drain the current fuel out of the line and pump before using it on the other fuel.
Do any of you have experience with this situation?
Is it worse to have gas in the diesel or diesel in the gas?

 

[Edke6bnl]

My diesel pump is not designed for gas, maybe yours is. I believe too much gas in a diesel will harm the motor, too much diesel in a gas motor will run bad but will not destroy it.

 

[MTBob]

The pump (12v, 1/4HP, 15gpm) I purchased claims that it can be used for both gas and diesel. But, I do understand that gas can adversely effect pump seals.

 

[PaulL]

I'd imagine that as long as you have small residual fuel, and do a decent fill, it'll blend out. If you pump a tiny amount of fuel for some reason you may end up well out of spec.

Personally I think I'd use separate pumps. The cost of a blown diesel will far outweigh any savings from having a single pump and hose. Probably 99 times out of a 100 you'll be fine. That 1 time, however.....

 

[NorthwoodsLife]

Personally I think I'd use separate pumps. The cost of a blown diesel will far outweigh any savings from having a single pump and hose. Probably 99 times out of a 100 you'll be fine. That 1 time, however.....

Yes, Definitely.

2 pumps, 2 tanks. 1 with Diesel. 1 with Gas. No question about it.

They say that it can be used for gas and diesel. But...it can't be used for both, back to back.

 

[Runs With Scissors]

Yes, Definitely.

2 pumps, 2 tanks. 1 with Diesel. 1 with Gas. No question about it.

They say that it can be used for gas and diesel. But...it can't be used for both, back to back.

This +1

My pump is for "non-gasoline" applications only though, so I would not attempt it anyway.

Besides the diesel transfer pumps are readily available for under 100 bucks for a cheap one and 300'ish for a nice one, so no need to chance cross contamination IMHO.

 

[mikester]

I'm building a "proper" transfer pump that will be used for diesel and gas. After filling my yard implements with gas, and then filling my tractor with diesel, am I likely to get too much residual gas in the diesel when I change to that fuel - or vice versa? I'm planning on holding the discharge line high enough to gravity drain the current fuel out of the line and pump before using it on the other fuel.
Do any of you have experience with this situation?
Is it worse to have gas in the diesel or diesel in the gas?

One way won't go boom boom very well the other way might go kaboom and boom boom no more.

Cleaning your loaded guns is a bad idea too.

 

[GreensvilleJay]

agree TWO pumps, YELLOW handle for diesel, BLACK for gasoline
BIG colorful labels on the tanks too !!!

 

[torch]

Pipelines alternate between products like gasoline and diesel all the time, and they can't drain the pipe in between. But... They divert the first bit of new product to a holding tank called "transmix". Basically using the new product to flush the old product.

If you are going to use one pump, you could squirt the first pint or so into a separate container. Maybe use that in an oil-burner stove or 2-stroke engine, depending on which product was the flush today.

 

[lugbolt]

diesel in gasoline can damage catalysts...melts them, slowly over time.

gas in diesel hurts injectors, pumps, etc--and i'm told by the folks at Bosch, it doesn't take very much gasoline in the fuel to hurt parts.

 

[MTBob]

All good comments, thanks!!!
Now I'm rethinking "My Great Idea".

 

[North Idaho Wolfman]

Simple answer NO! Don't do it!
You do not want any gasoline in your diesel!
Like others have said, 2 separate tanks, two separate pumps!

 

[PaulL]

agree TWO pumps, YELLOW handle for diesel, BLACK for gasoline
BIG colorful labels on the tanks too !!!

In my part of the world, yellow diesel, red gasoline. Black is sometimes used for diesel, sometimes used for gasoline. Not that it matters that much as long as you know which is which.

 

[GreensvilleJay]

yeah red for gas makes sense, though I've got yellow tape on 3 of them to say 'diesel' as I can't buy 10L yellow cans.....

I'd love to know WHO decided Kerosene should be in a BLUE container !!!!
Ok, at 70 I'm cynical but really when I see blue I think water, drinking water....

I remember the 1st Amazing Race, guy cheepd out at the filling station, put diesel into gas car...hehehehehe, didnt win, DOH !