Dorman Oil Drain Tube Kit 904-346 Caution

[Darkbloodmon]

I'm still in the throes of my clutch job on my 03 and then some with resealing everything and waiting on additional parts and bits. I noticed this as I was trying to install a 2nd Gen swap turbo drain line kit which won't clear on a 3rd gen stock turbo application....

I finally found the the source of a long term oil leak I had been monitoring. I replaced my turbo feed and drain lines/ hoses shortly after I got the truck. The drain tube kit I used was a Doorman 904-346, I got it off rock auto, but a quick search will show other diesel truck online retail vendors selling this Doorman kit, It came with a new bung including the O-ring, the hard line drain tube, gasket and the SILICONE hose fitting.

Silicone is not compatible with oil, unless it's chemically treated for it which this cheap Dorman set was not. Silicone hoses will sweat oil flowing through them. This sweating in my case was not enough to leave puddles, but small drips on the driveway, I've had this drain tube kit on for at least 10K miles before an oil analysis.

This further confirmed the results of my later oil analysis that had moderate to abnormal levels of silicone. At that time I had not re-sealed anything using silicone and nothing on the oiling system had been sealed with silicone products by the previous owners and as I'm looking at the nether side of my engine now doing a rear main seal and oil pan gasket; everything has a factory gasket.

Additionally in this kit; the Dorman bung appears to be a solid piece, but the fit with the O-ring feels sloppy in that you can swivel it around but feel the O-ring grab the sides. It's not comforting that it can be moved around so much with only the single O-ring holding it back. So I'll be looking for an OEM one or a higher quality aftermarket one that seals more securely.

Hope this helps someone.

 

[Darkbloodmon]

Update, I ordered a new drain fitting, and O-ring from Geno's and the fit of the OEM Cummins piece was night and day from the Dorman. The Dorman unit felt like a ball joint with the amount of swivel it had, The Cummins fitting is a press fit which I achieved with a 24mm socket, wobble extension, and a dead blow aiming from the passenger side. The OEM Cummins silicone hose grips the fitting so well, and forms around the notch instead of lifting off the fitting the further down it's pushed. Make sure the O-ring is lubed and put anti seize on the seat face.

I'm not a stark believer in OEM parts for every little thing, but I sure made the wrong call with this Dorman turbo drain kit, thankfully the OEM factory fitting was seized in the block when I was installing this kit a year ago so I was only able to replace the hard line tube and silicone hose. I was only now installing the fitting as I had my trans out for a clutch and had better access to get a chain vice grip wrench and a pry bar on the old fitting. Glad I have the right parts in, That Dorman fitting was stupid loose, I don't understand why it's so hard to make an exact copy of such simple products. A chemically treated silicone hose, an O-ring, and a steel drain fitting.

 

[Signal73]

Silicone hoses pretty much suck for automotive applications. We have a truck at work they are replacing all the coolant hoses that were silicone because they don’t leak, but the coolant odor sweats through the hose. The inside the cab and all around the engine outside smell like the truck has a coolant leak.

 

[Darkbloodmon]

Silicone hoses pretty much suck for automotive applications. We have a truck at work they are replacing all the coolant hoses that were silicone because they don’t leak, but the coolant odor sweats through the hose. The inside the cab and all around the engine outside smell like the truck has a coolant leak.

After this experience I would argue it depends on the manufacturer and materials, I have Mishimoto upper and lower rad hoses and they are an excellent improvement over the rubber ones that developed a bulge. Unless the silicone is chemically treated, there isn't any use for them on automotive applications besides Air and Coolant/water.

 

[seafish]

Silicone hoses pretty much suck for automotive applications. We have a truck at work they are replacing all the coolant hoses that were silicone because they don’t leak, but the coolant odor sweats through the hose. The inside the cab and all around the engine outside smell like the truck has a coolant leak.

Ive been running MrBobs silicone coolant hoses, and even PFC lined silcone oil return hoses with zero problems for many years.

 

[Timd32]

6yr with Mr Bob's as well. No issues.

OEM Cummins on the turbo drain stuff as well, always a good product no matter makes it for them.