[PURE340i]

Hey guys. Just had my DEF tank replaced. The bottom cap is the active tank refill correct? The top one is like a reservoir to fill the active tank up when it gets low if I recall correctly, but is the top tank suppose to be pressurized if you remove the cap? I topped off both tanks so i don't have to deal with it for a while, but if i remove the top cap after driving cycle its pressurized and DEF starts to spill out. Is this normal?

[kbsilver]

I'm not an expert but I believe both tanks are atmospherically vented and neither should be pressurized. DEF should not pour out (other than a little that my be sitting in the filler pipe) when the cap is removed. I only fill the passive tank to prevent the DEF from getting stale/old and possibly overfilling which can end up plugging the vent filter if the DEF crystallizes in vent. When I get the xxx miles to no start, I simply fill the passive tank with one 2.5 gallon jug of DEF. The pump will move it to the active tank. No start warning goes away after a few miles as I recall. 2.5 gallons for me is about 10K miles.

[PURE340i]

Originally Posted by kbsilver

I'm not an expert but I believe both tanks are atmospherically vented and neither should be pressurized. DEF should not pour out (other than a little that my be sitting in the filler pipe) when the cap is removed. I only fill the passive tank to prevent the DEF from getting stale/old and possibly overfilling which can end up plugging the vent filter if the DEF crystallizes in vent. When I get the xxx miles to no start, I simply fill the passive tank with one 2.5 gallon jug of DEF. The pump will move it to the active tank. No start warning goes away after a few miles as I recall. 2.5 gallons for me is about 10K miles.

Cool thanks. I actually popped open the cap again and it was no longer pressurized.