working on a 91 SDL. One of the collars that hold the injector in the head is cracked on both sides. It does not leak any diesel out but I am wondering if it might be letting air in ?
Second question is if I take it loose can I purchase just that collar or do I have to buy and injector ?
Can I use a collar from another MB injector or only 603 ?
Thanks
John

I would pm greazzer with this unless he sees it here first. He can get busy but he is the go to guy for injectors.

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The OM 642/722.9 powered family
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both my kids cars went to junkyard in 2023
2008 ML320 CDI (Older son’s DD) fatal transmission failure, water soaked/fried rear SAM, numerous other issues, just too far gone to save (165k miles)
2008 E320 Bluetec (Younger son's DD) injector failed open and diluted oil with diesel, spun main bearings (240k miles)

1998 E300DT sold to TimFreeh
1987 300TD sold to vstech

Before going crazy with injectors....is this the collar/retaining nut for the prechamber, or is this the lower half of the injector nozzle holder? There's a difference!

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Current stable:
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It is on the injector. The part that the wrench goes on to loosen to remove the injector,
JOHN

If the Injector is removed you can replace what I call the Nozzle Nut. That won't change the Pop Pressure. However, taking that nut off it is easy to get dirt inside.

It won't become a air leak because the pressure inside when the fuel is injected is greater then the pressure outside.

If it was mine I would simply leave it alone and keep and eye on it and aquire the parts to fix it.

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84 300D, 82 Volvo 244Gl Diesel

Trouble is you may as well do the rest of the injectors while you're there, to keep them balanced. Bit silly to only swap the nozzle holder and have it working unevenly.

If it's not too bad and isn't leaking I would be tempted to leave it. Injectors don't suck air in.

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1978 300D, 373,000km 617.912, 711.113 5 speed, 7.5mm superpump, HX30W turbo...many, many years in the making....
1977 280> 300D - 500,000km+ (to be sold...)
1984 240TD>300TD 121,000 miles, *gone*
1977 250 parts car
1988 Toyota Corona 2.0D *gone*
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1999 Hyundai Lantra 1.6 *gone*
1980s Lansing Bagnall FOER 5.2 Forklift (the Mk2 engine hoist)
2001 Holden Rodeo 4JB1T 2WD

You can remove the part circled in the pic and replace it and it does not change the opening pressure of the Injector.

One of the issues I mentioned is when you take it apart you can get dirt into it and the next issue is if you assemble it and don't lap the preacision surfaces it could seep fuel.

Attached Thumbnails

 

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84 300D, 82 Volvo 244Gl Diesel