This has been discussed on many forums for most of the model years with the SCR system. But although there is lots of discussion, I have yet to see where anyone completed such a modification. It makes one ask, how come? I plan to go forward with the modification and I will share my process and results here.
Some of you might say, "why?". Well, some of us have unique situations with our trucks that make DEF more likely to be a problem for us. For instance, I will drive my truck 4000-6000 miles a year. Most of that time is towing our RV. The rest of the time the truck is a garage queen. Driving so little makes for DEF being in the tank for a long time, and so I might want to drain it on occasion and refill to keep it fresh. Also keeping a low tank tends to cause other problems like drying out in the tank and producing solids. With a drain plug I can keep the tank full and then drain it when I believe it is getting too old. Secondly, I live in the middle of the Mojave Desert. It gets very hot for about 3-3.5 months out of the year, where daytime temps are never below 105 and usually hotter. This is bad for DEF, making the shelf life dive down to about 2-3 months. So again, being able to drain and put fresh DEF in the tank to avoid problems is desirable. I have no desire to do a delete on the SCR system for many reasons, so that isn't an option for me.
It is my understanding that on most model years siphoning the DEF out of the tank is not possible. There isn't a lot of info on the 2021 trucks like mine, but I have no reason to believe that has changed. A drain plug is the best and simplest way to accomplish what I want.
There are a lot of unknowns going down this road, and most surround what the inside of the tank looks like. I have no idea at this point, and I have found zero info on this. And the tank in the 2021/L5P is a different shape than previous models, so getting info on the inside of the tank is very difficult. I would like to know if the tank has baffles (if you know for sure please let me know), and if so, how are they laid out. Also, it would be nice to know where any electrics are inside the tank for things the truck needs to run like sampling or fluid level, etc. Cutting a wire during the valve install would cost a lot of coin to fix. Again, if you know, let me know.
I found a Blind bulkhead tank bung that isn't affected by Urea. It is made of stainless steel and the gaskets are made of nitrile, both are unaffected by Urea. You can see what I'm thinking about HERE. Unless one of you have a better idea, this is my plan for the drain plug.
I've been under the truck and looked at the tank and its mounting location. It is more of a bugger to get out than previous tanks. So, at this point it is my plan to cut the hole with the tank in place. The first of two locations I have decided on for cutting the hole is at the front of the tank on the outside/left side. The second choice is at the rear of the tank, again on the outside/left side of the tank. The biggest impediment to these locations are being able to get in there with a hole saw. It will probably take a 90 degree angle for the drill.
If anyone has ideas or constructive suggestions, speak up.
Some of you might say, "why?". Well, some of us have unique situations with our trucks that make DEF more likely to be a problem for us. For instance, I will drive my truck 4000-6000 miles a year. Most of that time is towing our RV. The rest of the time the truck is a garage queen. Driving so little makes for DEF being in the tank for a long time, and so I might want to drain it on occasion and refill to keep it fresh. Also keeping a low tank tends to cause other problems like drying out in the tank and producing solids. With a drain plug I can keep the tank full and then drain it when I believe it is getting too old. Secondly, I live in the middle of the Mojave Desert. It gets very hot for about 3-3.5 months out of the year, where daytime temps are never below 105 and usually hotter. This is bad for DEF, making the shelf life dive down to about 2-3 months. So again, being able to drain and put fresh DEF in the tank to avoid problems is desirable. I have no desire to do a delete on the SCR system for many reasons, so that isn't an option for me.
It is my understanding that on most model years siphoning the DEF out of the tank is not possible. There isn't a lot of info on the 2021 trucks like mine, but I have no reason to believe that has changed. A drain plug is the best and simplest way to accomplish what I want.
There are a lot of unknowns going down this road, and most surround what the inside of the tank looks like. I have no idea at this point, and I have found zero info on this. And the tank in the 2021/L5P is a different shape than previous models, so getting info on the inside of the tank is very difficult. I would like to know if the tank has baffles (if you know for sure please let me know), and if so, how are they laid out. Also, it would be nice to know where any electrics are inside the tank for things the truck needs to run like sampling or fluid level, etc. Cutting a wire during the valve install would cost a lot of coin to fix. Again, if you know, let me know.
I found a Blind bulkhead tank bung that isn't affected by Urea. It is made of stainless steel and the gaskets are made of nitrile, both are unaffected by Urea. You can see what I'm thinking about HERE. Unless one of you have a better idea, this is my plan for the drain plug.
I've been under the truck and looked at the tank and its mounting location. It is more of a bugger to get out than previous tanks. So, at this point it is my plan to cut the hole with the tank in place. The first of two locations I have decided on for cutting the hole is at the front of the tank on the outside/left side. The second choice is at the rear of the tank, again on the outside/left side of the tank. The biggest impediment to these locations are being able to get in there with a hole saw. It will probably take a 90 degree angle for the drill.
If anyone has ideas or constructive suggestions, speak up.
