Def header/ sending unit replacement on a freightliner Cascadia. Inaccurate def gauge. Coolant leak

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How to replace a def level unit/sending unit/header unit from a def tank. Either inaccurate def gauge or coolant leak at top of sending unit. Whatever you reason is This is how its done.

[@h22amonsterb18c]

Did one on a M2 today and have one on a sleeper tomorrow thanks for the refresher my dude

[@brytonkupser3312]

I've never done this before nor trained how to do it and this video helped substantially! Thank you!

[@bustedknucklebydieseldr3228]

Thanks for reaching out ,glad this came in handy for you. hopefully more videos on this channel prove themselves useful to you. Stay safe out there

[@richardgeister5423]

Thanks for posting this video I am replacing my def tank and header as its cheaper to buy that way then just the header. Nice to be able to see it explained so well .

[@Traveler5824]

00

[@josemayoral5596]

Good education for the ones who like to get duty,thanks keep up the great work.👌💪

[@stanlyhanson2142]

I was messing with that sensor clip for an hour before I found this video I didn’t realize the red one slid over first.

[@josecuellar775]

Oh thank you very much for the information you have a nice day my friend

[@bustedknucklebydieseldr3228]

Very welcome, glad to help in any way. Stay safe out there

[@mfddb3084]

Good to know that I'm not the only one making weird sound effects when I'm wrenching on shit lol

[@bustedknucklebydieseldr3228]

Haha ya we’re all a bunch of weirdos. A special breed if you will.

[@jerometaylor554]

Guess I better order my tank/header and get to work

[@tsehayearaia2450]

Thanks for your sheering your knowledge! How I flash my radiator ?

[@jamespemberton6593]

Busted knuckle. Thank you for your videos. My low def light keeps flashing and my turbo and voltage meter aren't working at the same time. Then randomly it will work for maybe 30 min then stop again. It's a 2015 frieghtliner cascadia dd13. Any info would be much appreciated. I am at a loss and not enough money in the bank to take to dealer. Hope you have a great day.

[@bustedknucklebydieseldr3228]

I believe you have two separate issues here. Could be a simple voltage or battery issue for that gauge issue. The def light will need a computer to diagnose , so hopefully you have a buddy with a diag computer to look at those code.

[@steveowens3142]

Thank you JD

[@demichealburton2536]

Bro your channel is very helpful

[@bustedknucklebydieseldr3228]

Always appreciate that positive feedback.

[@rooseveltrainesjr7618]

Good video thanks

[@pedrotamayo8561]

Thanks very much

[@BlitzedNostradamus]

Keep em comin' buddy.

[@bustedknucklebydieseldr3228]

Thanks for the positive feedback

[@chillywilly9611]

Thank you! Great video!

[@bustedknucklebydieseldr3228]

Appreciate it man. And awesome name by the way.

[@rooseveltrainesjr7618]

Freighter just replaced my bad Def pump Filters in my 1 box. Knock sensor. My 18 model derate an I had to get it tow.

[@bustedknucklebydieseldr3228]

When it derates it’s a horrible thing. But atleast you weren’t stuck on a freeway.

[@calgarynorthwestmal8162]

In most cases you don't need to slide the DEFD tank out to remove the DEF header, you can remove the header from tank on it's original place, and in most cases you can repair the header if it doesn't show major cracks.

[@shdadedam7355]

Bro did you see how long was the heater inside the tank? How could you take it out of the tank when don’t need to slide the tank out???

[@ravshana]

Does coolant have to be drained before attempting to replace this header?

[@bustedknucklebydieseldr3228]

Thanks for recahing out. The coolant should be drained to make it easier but if you have pinch of pliers you can work around this and just work quick.

[@tittat2440]

Was wondering rigging a heater into fuel tanks and connect to APU this freeze in the Cascades a headache is it do able

[@JorgeMartinez-nj2jk]

Jorge Martine thank you for sharing your knowledge have you ever cross with dd15 fault codes 521049, 521050, 521052 all fmi 31? and fix it? thank you

[@bustedknucklebydieseldr3228]

So that code is just a def inducement code. That would typically mean any def related issue would cause this to come active. Do basics. Check all the sensors for any drifting, checking def doser for the correct amount produced , check the onebox for any excessive build up. One of these should lead you to your issue. Realistically a computer would be needed to assist in diag so without that your kinda limited. Hope that helps.

[@derrickrichardson2395]

Will a bad sending unit cause those coolent line connecters to keep breaking off and shooting coolant everywhere?

[@yevgenaleksyeyenko8291]

Thanks bro

[@johnbuitragoqww7958]

Hey man . What cause that the def gauge not going down . I drove my truck already like 2400 miles and the tank still full. I disconnect all the lines def is coming down , so the lines are not clogged. I already change the def pump because i have code 4374 fmi 0. Thanks for videos and help.

[@bustedknucklebydieseldr3228]

Great question. That actuall use of def is very minimal but over time it should go down. The gauge might not match the actual level. If the tank Is still full after that many miles I wouldnt worry about it. If a cel comes on for def related issues than we worry. There are many factors that cause def usage and less usage. So if the system is working fine and your barley using any than I’d say we’re ok still.

[@mariselaadame1050]

I am trying to replace the air vent for the DEF tank. Do you have a video that shows how to?

[@bustedknucklebydieseldr3228]

Thanks for reaching out. I do not but that is a good idea. They do just snap off but will majority of the time break apart due to age.

[@alextrucking2204]

Good video hello question what is price of DEF HEADER?

[@sebastianstarnes4291]

So drain the coolant first would be a good tip cause I tried removing the coolant hoses and coolant shot out and continued to pour for a while

[@bustedknucklebydieseldr3228]

Well you got a few choices with the coolant. And leaving it alone is prob not a good option. You’ll learn real quick. I prefer putting it under a vaccum and very little comes out at that point.

[@ivanhernandez5682]

MR KNUCKLE BIG FAN! Of you bro. GOOD VIBES GOOD JOB . 👍 Why did you replace it

[@bustedknucklebydieseldr3228]

Thanks for watching and the positive feedback. Exactly what I need. I replaced this one due to def contamination mixing with the coolant. When that happens you flush the def tank, replace the pump and replace the def header unit. Other reasons to replace it is gauge showing incorrect level in icu or check eng line for circuit codes related to the header unit. Hope that helps

[@ivanhernandez5682]

@@bustedknucklebydieseldr3228. THANKS YOU FOR THE REPLY MR KNUCKLE. So the coolant line broke?.. how did you know it was mix. .. did you had a check engine light..

[@bustedknucklebydieseldr3228]

@@ivanhernandez5682 Surprisingly there was no check engine light but when I was doing another repair for the cooling system I noticed a strong DEF smell in the coolant reservoir. Than I just went from there to the only possibly sources.

[@ivanhernandez5682]

@@bustedknucklebydieseldr3228 alright Alright. That's good to know. Thank you bro... 🔧. Stay posted with the good videos..

[@alr9170]

Need some help with Dd15. DEPF filter Clean, EGR Clean, DEF doser Clean, DEF filter Replace 5 months ago, but the truck keep asking for Rgen every 500 miles. Any idea what can be the problem?

[@bustedknucklebydieseldr3228]

With consistent regens this is usually due to low loads with the truck and bad rpm ranges. I often see units over 1800rpm for majority of the travel time and this will cause over fueling leading to more regens. Could be as simple as this or something much more troublesome like a onebox not cleaning well enough.

[@unclemike8467]

JD will you do this same repair on a New Cascadia sometime? Remember I’m one of your earliest subscribers :-)

[@bustedknucklebydieseldr3228]

Been with me from the beginning , I appreciate that. I guess the trouble with that is I have yet to have one go bad on a 2018 and up. So far looks like there lasting. But give it some miles and I’m sure they will start going out.

[@unclemike8467]

We’ll that’s actually good news for a system that hardly ever has good news. Keep me in mind when you do see it in the future, which we both know you will.

[@fahimrehrah5266]

Hello . I have def light blinking with full def tank ! And I can’t drive over 55 mph . Any help what to do please?

[@bustedknucklebydieseldr3228]

There is a code that’s logged that’s derating you. Best thing to do is have a diagnostic computer hooked up otherwise we’d play the guessing game and that’s no fun.

[@brandoncooper4868]

Do you have to plugin and reset anything with the software?

[@bustedknucklebydieseldr3228]

Thanks for reaching out man I do appreciate hearing from you guys. There is nothing to reset with this repair just plug and play. I do like to do an SCRADS self check through the computer to make sure nothing is leaking but that’s all.

[@brandoncooper4868]

@@bustedknucklebydieseldr3228 awesome thanks

[@dave684333]

Cascadia 2016 dd15 .def empty light on .but my def tank is full.. what happens..please help..thanks

[@bustedknucklebydieseldr3228]

Thanks for reaching out. Well I’m no magician but you have one of a few failures. Def sender unit,, wiring failure,, or def gauge inaccurate.

[@LittleRedsGarage]

Ive got a 2013 cascadia and the DEF quality light comes on, been to the dealer several times cant find anything wrong. Is the DEF quality sensor made into the sending unit? Im thinking the sensor is malfunctioning randomly.

[@bustedknucklebydieseldr3228]

Great question man. On the older models there are built into the def metering unit on the side of the one box. Unfortunately that style usually gets built up and dried def in there and throws off the readings. There’s not a true fix other than flushing that metering unit often. As long as you know for sure the rest of the system is fine. Just a poorly made design. But they did improve in the next generations higher.. hope that helps somewhat. Stay safe out there.

[@WorldPremiere2018]

What’s Up JD This just happened over the weekend DEF is Full But The Gauge is showing 1/4 ? Do you think the sensor needs changing And how did you drain the tank?? In the Video

[@bustedknucklebydieseldr3228]

Thanks for reaching out. Def header is most likely the culprit. Either screwing up or def crystals on the float. You can pull it out, plug it in and test it with the icu gauge. There is no drain for the tank. So sucking the fluid out or just being careful moving it are the only options.

[@WorldPremiere2018]

@@bustedknucklebydieseldr3228 Thanks Bro I Can Always Count On You!!

[@GangstaVI1]

I got a coolant leak coming from the valve or one of the lines…what I want to know is can i block the lines if my DEF is deleted to prevent the leak?

[@bustedknucklebydieseldr3228]

Great question, and yes deff you can block the lines if your stuff has been deleted. I would find plugs for where they go into the coolant pass through manifold on the upper p/s of the engine. That was you don’t have to worry about the lines at all.

[@GangstaVI1]

@@bustedknucklebydieseldr3228 thanks a lot man definitely will do that! Bout to subscribe to your channel as well!

[@hassanelhuur2494]

Hello, Diesel Dr. I am trying to bring in my truck… where in Phoenix, AZ? Where is the shop you work for or have one yet? Address, I am trying to stop by to fix high air gauge pressure… 150 PSI and above. Thanks.

[@bustedknucklebydieseldr3228]

Thanks for the reach out I replied to your other msg about the press issue. I don’t have my own shop yet or a shop I can name on here but hopefully if this channels takes off I can get one started. Thanks for watching and showing support.

[@robertwhite3732]

I have a leak around the coolant fitting That’s on the top of the dpf tank is there suppose to be a rubber seal on it?

[@bustedknucklebydieseldr3228]

Great question, I guess it would depend on what exactly is leaking. The fittings on the def tank are built into the header unit itself and can’t be replaced so if it’s leaking the def header will need to be replaced. A lot of times the line is the issue and the line will need to be replaced. So just have to differentiate between the two.

[@robertwhite3732]

Thanks for the response I guess I’ll be replacing a coolant line in the morning

[@verajavi12]

No electric motor as part of sending unit??

[@bustedknucklebydieseldr3228]

There is a solenoid to control coolant flow on top of the the header. But no bulky motor.

[@ronaldparker2643]

I have a 2012 freightliner m2 106, fault code 3651 and my def tank is abnormally hot. Would you say this issue is the cause of a bad Def header and or def heater tank valve ? Also is it safe to drive while my engine light is throwing this code ?

[@caucasiansensation147]

I'm dealing with derate issues concerning DEF quality on a 2017 cascadia with a dd15 in it. I know very little about detroits. Is the DEF quality sensor built into this tank head?

[@bustedknucklebydieseldr3228]

Quality readings will get is values from the def tank header itself. I would check for a diluted system which a refractometer would come in handy with that.

[@caucasiansensation147]

@bustedknucklebydieseldr3228 didn't have a refractometer, but got Diagnostic Link 8 from a friend. Found the reading of quality was stable but reading diluted @ 28.7% urea/water. Siphoned out all the old stuff and put in new stuff out of jugs (we normally buy our bulk DEF from Love's) and it straightened up after a regen and 100 miles of driving. Back to full power now. Thanks for getting back to me!

[@SFMARK69]

@@caucasiansensation147how have you been running with that bottle def ? I have never used the bottle def, I too always get bulk def from loves, since this comment have you noticed a difference?

[@caucasiansensation147]

@SFMARK69 Yes, things have improved since switching to DEF jugs. In those times jugs aren't available, we have refractometers in every truck and instructed our drivers how to test bulk DEF before filling the truck's tank

[@SFMARK69]

@@caucasiansensation147 testing the def? How are they doing that? Is that easy to do ?

[@toplinkslogistic8736]

Low def light came on, speed derated down to 55mph, and now i have a stop light

[@bustedknucklebydieseldr3228]

Sounds like you have what we call in the industry a problem.

[@glackaglack1534]

What code this issue caused to pop up if a any ?

[@bustedknucklebydieseldr3228]

So this issue was the driver telling me his def gauge was inaccurate. There are codes that will cause this to be replaced but not in this case.

[@glackaglack1534]

Oh ok. Spn 4273 pop and I replaced the def pump and that code came right back along with spn 3936. So now literally just throwing parts at the truck to get rid of the codes.

[@JoseVargas-km1xq]

Where the shop you work i think I'm bringing you my truck

[@bustedknucklebydieseldr3228]

Appreciate you watching and reaching out. Unfortunately I can’t mention my shop on here but as always I recommend dealers because of there knowledge and specialty tooling.

[@abneralvarenga4118]

Hi, thanks for the video, changed mine but light came back on. Do I have to force regen?

[@bustedknucklebydieseldr3228]

Thanks for reaching out. I guess it depends what light is coming on. If it’s the low def light than either wiring issue or stuck def on the sending unit. If it’s the check eng light than it may need to be cleared or ads self check routine may need to be ran. Regen should not be needed for this repair but a computer will definitely be needed. Hope that helps

[@johnsnow3457]

@@bustedknucklebydieseldr3228 pls advise. I dont have any fault codes. But my def pressure is low 7 psi almost all the time. Replaced def pump, one of the def lines from pump to the def tank cuz i had fault code def heater line # 5, then I replaced it. But i still have this issue. When its 20 F outside i noticed white smoke coming from exhaust pipe on a cold start. And I hear weird cyclic noise on a low rpm sometimes especially when its cold outside (my def pressure 160 psi at that time).

[@bustedknucklebydieseldr3228]

@@johnsnow3457 Thanks for reaching out man, what year is your truck or ghg model if you know it.

[@johnsnow3457]

@@bustedknucklebydieseldr3228 freightliner cascadia dd13 2018

[@bustedknucklebydieseldr3228]

@@johnsnow3457 well I guess my question is how do you know your pressure is 7psi. Are you able to run a ads self check or a def quantity routine. Because those two right there will direct you to an issue. Low pressure is usually failed pump or clogged screens.

[@ThinkEagle7]

Do you have to drain the coolant?

[@bustedknucklebydieseldr3228]

You have three options. Drain system. Put system under and vacuum. Or pinch of the flexible coolant lines to the def header.

[@ThinkEagle7]

I changed everything, but still, the light is still blinking with the stop engine sign.

[@bustedknucklebydieseldr3228]

@@ThinkEagle7 you will need a diagnostic computer for this but the system will need to be run either a regen or an ats self Check to make sure everything still operating properly.

[@СтепанБандера-ы8у]

Nice 👍🏻

[@fightsforrights]

Bro do you have to do regen to computer affer installing sending unit?

[@bustedknucklebydieseldr3228]

Good question. You do not have to do a regen but it is good to do a ads prime and self check through a computer.

[@fightsforrights]

@@bustedknucklebydieseldr3228We had a road service come out and did a diagnostic on the truck and said active codes were for the header or sending unit. We got part from dealer and still truck runs barey 5 miles per hour.

[@bustedknucklebydieseldr3228]

@@fightsforrights sounds like you had a bad diagnostic done. But just replacing the part doesn’t fix any issue. Truck needs to see that the part is good so test need to be done such as the ads self check routine. Hope that helps.

[@fightsforrights]

@@bustedknucklebydieseldr3228 Thank you, I really appreciate it.

[@fightsforrights]

Btw what does ads means I am new to this def scr problems.

[@kwadjookai8172]

How much is a job like this

[@bustedknucklebydieseldr3228]

Thank for watching and reaching out. For a def sending unit replacement figure about few hundred in parts and 5 hrs of whatever the door rate is.Hope that helps and dont forget pass these videos around.They make a great bday present.

[@wnatasheh]

Where is your shop

[@bustedknucklebydieseldr3228]

No personal shop yet but hopefully in the near future. Thanks for watching and reaching out

[@tabcaan22]

Tkns

[@tazzeman211]

Got a question about def gauge can you respond

[@bustedknucklebydieseldr3228]

Sure thing.. what’s going on with your gauge.

[@fahimrehrah5266]

Spn 6162 code

[@CashNYC]

Spn 5397 fmi 31 can u explain solution for this problem?