[Vwdiesel] Injection pump testing for beginners 10. ----( orifice bolt )

H.Hagar h_hagar at prcn.org
Mon Oct 25 10:06:16 EDT 2004

Where do we find the bolt ?  ---  it is the bolt that holds down the "OUTLET"  banjo
on top of pumps   with no LDA.

Look carefully at the bolt and you will see a very small hole -- that is the orifice.

The inside of the bolt is hollow and there is a filter installed to protect orifice from dirt.

I have done a lot of experiments with these pumps (107 A)     but never paid much attention to

Mark Shepherd  mentioned the possibility that orifice may enlarge over
time and thus lower internal pump pressure.        Interesting   I shall look in to it.
Further I am going to ask BOSCH if special bolts are available for the skinny shitty fuel
we are getting these days.   Gavrik Peterson you have a connection to  a repair station ?
Would you check that out ?       Off the top of my head I would say that the regulator
valve will compensate for small changes ---but we want to know --for SURE.


PS :    when you get an old Rabbit make sure it say "OUT"  on that bolt.   Yes
someone may have used an inlet bolt. 

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