Low mileage 2011 f750 Cummins 6.7

[Skizzlez]

Quick update:
Getting truck back from service center today -- they replaced the SCR under a campaign.

I asked the tech to look at the urea doser, because of the crystallized DEF hanging from it. He called me this morning to let me know I should replace the doser, because it is all caked up and corroding at the tip. He suspects it is leaking, causing the 3574 low pressure code. Which was what I was thinking too..

He wanted $500 to swap the valve, but being that it is only 10 miles from my own shop, i'm just going to do it myself -- the parts can be had for $150 i've seen. Anyone used one of the aftermarket brands that hang out on Ebay/Amazon? I'd imagine they are just serviced bosch units, but they are only $40.. thoughts? Doser Part number is 2888173 -- just for reference.

Hoping this solves the low pressure code.

Next job is to service the EGR system =)

Thanks,
Jason

[Waterloo]

Get the real thing, odds are it will last a quite a bit longer than the eBay parts... Critical parts, and that Doser is, best to use OEM parts. Many of us have been there, and done that, and it is usually never worth the savings.

[Chamberpains]

if you can verify that they are actual Bosch parts I might take a chance. But if they are chinesium aftermarket stay away.

[Skizzlez]

Sounds good. I figured that was the case - but ya never know. You guys may have tested and verified they work.

Thanks as always.

[JimT]

I tried that $40 Amazon route for the DEF doser. Was leaking from the moment I installed it. Only ran a month or so before the system was abolished, so I can't say what long term effects would have been seen.

The doser appeared 100% legit. I'm guessing maybe it didn't pass QC inspection? Or maybe it was just an extra production run, off the books. Either way if I had to buy one again I'd go with an authentic one that you can return if it's defective.

Also, do some research, there's a metal gasket and an isolator that goes between the doser and the mounting bracket on the can. Not sure if it applies to your engine, but at some point they updated the design and the gasket and isolator are a different size. They are both compatable with any can or doser, but the gasket and isolator need to match. When replacing the doser you should replace the isolator as well and that might mean you need a newer gasket to match.

Info about this was found on quickserve.

[Skizzlez]

Thanks Jim,
Saw that about the gasket and isolator. Plan to get those as well.

(08-21-2020 )JimT Wrote:  I tried that $40 Amazon route for the DEF doser. Was leaking from the moment I installed it. Only ran a month or so before the system was abolished, so I can't say what long term effects would have been seen.

The doser appeared 100% legit. I'm guessing maybe it didn't pass QC inspection? Or maybe it was just an extra production run, off the books. Either way if I had to buy one again I'd go with an authentic one that you can return if it's defective.

Also, do some research, there's a metal gasket and an isolator that goes between the doser and the mounting bracket on the can. Not sure if it applies to your engine, but at some point they updated the design and the gasket and isolator are a different size. They are both compatable with any can or doser, but the gasket and isolator need to match. When replacing the doser you should replace the isolator as well and that might mean you need a newer gasket to match.

Info about this was found on quickserve.

[Skizzlez]

Hey guys, been a bit since I've been on here, but have a question regarding code p3574 - at least I think that's it off the top of my head..

Been driving the truck a bit here and there since the Cummins shop replaced the scr. Changed the doser with a genuine Cummins unit. But still had the low def pressure periodically. Eventually it would derate and shut me down. I ran the aftertreatment test numerous times, it always passes first try, no leaks. Gets to 130psi and holds it. Does take about 20 to 25 seconds to build that pressure, but it makes it..

The other day I ordered a replacement def pump, because I can't see anything else in line that would cause they low pressure code.. it's just the lines, pump and doser. Swapped the pump tonight, and will test drive Tuesday. Ram the leak test, same deal, seems to pass just fine.

Also, popped the old one apart. Looks brand new inside.

Jasom

[Rawze]

And what about the DEF filter screen?

[Skizzlez]

In the tank? Or the filter in the pump?
Changed the filter in the pump, on the old one. Still had the issue.

The new pump came with a new filter too.