DEF

Good Morning,

I usually fill up with fuel at truck stops - FlyingJ, Pilot, Love's. Anyone have any idea why, or maybe it is just my coach, the DEF tank is on the opposite side from the DEF hose? It is a semi pain to buy the boxes of DEF and add to the tank. I would much rather pump it in when I stop for fuel. Just wondering.

Because a lot (or most) RV's are not designed by anyone who actually uses them.  It probably would have cost $10 more to put the tank on the other side or route fill tube from the fuel fill side to the tank on the other side.

For whatever reason (maybe just a convenient place for the factory), Freightliner Custom Chassis originally located the DEF tank on the right side and no RV manufacturer went to the extra trouble/expense of relocating it or routing a filler from the driver side.  After hearing numerous complaints (it was a dumb design!), FTL moved the DEF tank to the street (driver) side, I think in the 2015 calendar year (so it shows up in 2016 models).    However, only on rear radiator models that year - side radiator chassis apparently didn't have a suitable location available.  I've heard that both FCCC  and Spartan are working on a solution for side radiator chassis, but I don't know the status of that.

Supposedly the DEF tank & feed line needs to be reasonably close to the engine exhaust system and protected from freezing. DEF freezes at about 12 F., so not a problem for most RVers, but the design has to work for everybody, not just most rigs.

One more reason I like my Frieghtliner M2 106 Chassis. It is set up for driving. The DEF tank is located where it should be on my Dynamax.

Gary RV_Wizard said:

For whatever reason (maybe just a convenient place for the factory), Freightliner Custom Chassis originally located the DEF tank on the right side and no RV manufacturer went to the extra trouble/expense of relocating it or routing a filler from the driver side.  After hearing numerous complaints (it was a dumb design!), FTL moved the DEF tank to the street (driver) side, I think in the 2015 calendar year (so it shows up in 2016 models).    However, only on rear radiator models that year - side radiator chassis apparently didn't have a suitable location available.  I've heard that both FCCC  and Spartan are working on a solution for side radiator chassis, but I don't know the status of that.

Supposedly the DEF tank & feed line needs to be reasonably close to the engine exhaust system and protected from freezing. DEF freezes at about 12 F., so not a problem for most RVers, but the design has to work for everybody, not just most rigs.

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Protected from freezing? What happens to the DEF in my truck during sub-zero weather?

Joel

It also depends on the coach model. Our 2011 Winnie (Freightliner chassis) has the DEF tank on the driver's side. Of course it's about 30 feet behind the diesel filler ports, so if I want to fill the DEF tank at the pumps, I still usually have to move the coach.

Kev

Great Horned Owl said:

Protected from freezing? What happens to the DEF in my truck during sub-zero weather?

Joel

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IT FREEZES;
From www.powerblanket.com/def-freezing-def-cold-weather/
"When Does DEF Freeze?

DEF, because of the urea, doesn?t have the freezing point of water. The urea mixture has a much lower freezing point of 12?F/-11?C. This solution doesn?t break into just urea and just water, either. The solution freezes at the same rate, and also thaws at the same rate. This means that at no point does the DEF freezing cause the solution to become over concentrated or diluted. DEF will begin to slush and then freeze.  There is no harm to the product which means that the urea solution is still safe to use if it has been frozen.
DEF Freezing and Expansion

Though it is safe to use again once thawed, expansion from freezing could cause problems.  Since DEF is a mixture of deionized water and urea, it reacts somewhat like water in that it does expand when frozen. DEF freezing usually causes about a 7% expansion. It is important to note that DEF freezing is usually taken into account when creating the packaging and tanks that are supposed to hold DEF. DEF packaging and tanks allow for expansion. However, one must be aware of the expansion of DEF when filling.  When storing equipment overnight or longer in temperatures that could result in DEF freezing, it is important to make sure the DEF tank on the equipment is not completely full or that it has an appropriate heat source. This will allow for expansion and help prevent cracking of the storage reservoir.
How to Prevent DEF Freezing?

DEF freezing was taken into account by the OEMs prior to creating the Selective Catalytic Reduction (SCR) systems. Therefore, the SCR systems are designed to provide heating for the DEF tank and supply lines; however, if the vehicle is shut down and exposed to freezing temperatures, then it is likely that the DEF will freeze. Diesel owners do not need to worry about DEF interfering with their vehicle, however. If DEF freezes when the vehicle is shutdown, startup and normal operation of the vehicle will not be inhibited. In most cases, the SCR heating system will quickly thaw the DEF in order to return it to liquid form and resume normal operation."

Our 2016 Berkshire still has it on the passenger side. I do have Fuel fill on both sides. If I am getting low and find it possible i just go through the fuel island backwards and can fill both tanks.

I'm still waiting for someone to market ABC brand DEF.    ;D

Lou Schneider said:

I'm still waiting for someone to market ABC brand DEF.    ;D

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: ;D ;D ;D