Hi, here's a short testimonial and a good URL:
I sealed a JX pump last night that was leaking, apparently between the high-pressure and low-pressure sections, and it seems to have originated from Poel.
My bus colleague showed up with a pump: "If the prophet doesn't come to the pump, the pump will come to the prophet" - alright, then hand over the thing.
BOSCH had previously faxed the exploded diagram and quickly delivered the corresponding seal.
http://www.uwereimann.de/poel/esp-hd.htm showed us what to expect.
With the expanded ESP system, the O-ring was replaced in less than an hour.
My pictures are very similar to the ones on Uwe's website.
http://www.luxus-wg.de/~martin/auto_bilder/ESP/
What can already be seen are the "pressure marks" that the Poel leaves on the wall of the high-pressure section when it is released and returns to the high-pressure piston, because the control slide retracts.
Similar work on a TDI pump can be seen here (but they are similar

).
Okay, I'm ready. Please provide the German text you want me to translate.