compression loss through leaking injector
 

I had to remove all the injectors recently in order to get the rocker cover off. When I was replacing this I bought new copper washers and stretch bolts and sealed all except one as it was blowing fuel and air out ofd the cylinder. I undid the new bolt removed the injector and turned the new washer over. Before I put everything back in place I clean as much of the muck out of the injector chamber. On tightening it did seal on this attempt and I thought it had been a success although I thought I really should have waited and got a new copper washer and Streetch bolt as I had already just used both although only for a short period. What should I do now.I am concerned that taking the stretch bolt in and out could lead to damage to the threads or the bolt snapping. Any toughts would be appreeciated. The sealed unit has lasted about 1500 miles befoer leaking again.
rgds

Amac

loss of compression
 

I am in the uk its a 2004 e270 avantgarde

rgds amac