Volvo D13 injector cups fail again !

I had my injectors done at the same place where they gave me the quote to do it agin and it's a volvo mack dealership l

 

D13 , 2014, hard start, bubbles in tank return line. Got injectors lab tested and i was told injector 3 & 6 are not sealing with cups. Only option is to replace injectors. not left with much option. asked my mechanic if a copper shim can be added between injector & stainless steel Cup for tighter seal, but mechanic is hesitant to take chances. ANY IDEAS?

 

When you say lab tested you pull them out to test for flow test or is there some other test. Other option is to replace cups only or cups plus 2 new o rings top and bottom one.

 

basically test is to determine if injectors are functioning as they should, any leaks, contact surface, life. yes pulled out for testing. steel cups require only top O ring.

 

Can anyone tell me i hve a 2008 volvo d13 and replaced head and i need to know torque on head bolts in ft lbs plz i know sequenece but not ft lbs thanks

 

No, this is the major design flaw with "conical" "new" style injectors.
The old brass design should've been kept but change to stainless material instead....