603 injector questions
 

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.

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!

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.

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.

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.