Leak Oil Line / Common Rail Return Line / Fuel Injector Return Line -- FIX

ScoCan

Member
While doing a fuel filter replacement on our 2014 NCV3 OM642.896 3.0L I managed to snap off the passenger side of the leak oil line at the "tee" which is directly forward of the fuel filter.

This is a write up of 2 methods of fixing the issue, one temporary and the other a full replacement.

Temporary Fix:
The Sprinter needed to be moved about an hour down the road to my workshop before I could replace the leak oil line.

Older model leak oil lines had replaceable Tee's. Throwing the dice, I bought a set of metal replacement Tee's for the older model leak oil line off ebay. Comparing the metal Tee to the OEM broken plastic one, the dimensions were identical for all practical purposes (visually and per micrometer).

Installation involved carefully drilling out the remnants of the plastic Tee. The leak oil line is hose in a hose construction, with braiding between the inner and outer hoses.

The metal Tee went in easily and was secured with 2 hose clamps. Total time was minimal. Checked for leaks several times while en route -- no problems at all. Probably could have left it in indefinitely.

I've added it to my Sprinter repair kit that always stays with the vehicle.

Metal_Tee_Inset.jpg

-- I've got a couple extras if anyone is interested (PM me), includes the metal tee, 2 hose clamps, retaining clip, postage in USA or Canada: $15.00 USD.

Permanent Fix:

Many thanks to @capav8r and @lindenengineering for their incredibly helpful assistance.

View attachment Leak Oil Line Replacement - v1.01.pdf

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Original thread from when I broke the Tee:
https://sprinter-source.com/forum/showthread.php?t=79322

Other related threads:
https://sprinter-source.com/forum/showthread.php?t=72311
https://sprinter-source.com/forum/showthread.php?t=56139
https://sprinter-source.com/forum/showthread.php?t=44290
https://sprinter-source.com/forum/showthread.php?t=9926
 

bcislander

'07 Mercedes-badged Dodge
Fuel injector clamps would have been much better to implement a permanent repair.

As an temporary emergency repair the 'worm' drive ones are OK.
 

lindenengineering

Well-known member
Just a comment .
The tee fitting you broke off forms parts of a Bosch REQUIRED back pressure of 0,5 Bar in the return line for Blurrtech Sprinter injectors.
Essential for correct filling of the internal injector cavity around the internal piezo armature, a constant back pressure therefore must exist and is created by that measured internal aperture factory tee fitting.
Replacing it with an off market tee is OK in the short term as a field fix.
Its however in no way recommended for long term use, as it can effect injector operation, and fire up after a teardown, due to air trapped in the injector. and difficulty to purge it out, causing misfires & smooth operation .
Dennis
 

68protour

07 D 144 high rebadged MB
I'm thinking of reinforcing my existing unbroken tee fitting with JB well. Is there any reason to not do this preventive task?? Thanks
 

gemcoska

New member
@ScoCan

Thanks so much for this write-up! I'm going to be ordering part now and doing the replacement.

I've read on here that the process is about 2-3 hours, would you agree with that?

The process calls out for the following tools/materials, do you recommend buying these or can the job be done w/o them?
- Set of Stop Plugs 129 589 00 91 00
- Set of protective covers 001 589 01 91 00
- Lubricating Paste A 000 989 01 60
- Open wrench insert (18mm) 000 589 30 01 00
- Box wrench bit 000 589 68 03 00

I'd like to make sure I don't have to take any shortcuts for this repair.

Just to be thorough I added quantities added to parts list
- O-rings x 6 A 000 078 05 80
- Leak Oil Line x 1 A 642 070 81 32
- Seal Ring x 1 A 642 094 00 51
- O-Ring x 1 A 014 997 64 45
- O-Ring x 1 A 019 997 75 45 (A019972205 alt pn)

Again... THANK YOU.
 

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