Changing the delivery valve O-rings and lost a DV spring...
Changing the delivery valve O-rings and lost a DV spring...
I don't like doing this job, and on the last delivery valve today I experienced wobbly fingers and dropped the spring which has been swallowed up in the engine bay somewhere near the AC Pump on an OM605 Turbo with EDC Pump.
I have fitted a spring off my donor engines injector pump (also OM605 Turbo with EDC) which appears identical and has 50k more likes on it.
Is this likely to cause an issue?
Cool, so all EDC om605 turbo pumps use the same delivery valve spring?
Good times. It runs fine so I guess it's cool.
It is a black hole. . I think a lot of the cast mounting brackets have a gap behind them and stuff gets in there and stuck in corners.
all bosch inlines use the same DV holder Spring... maybe overtime they changed part number
that thing is only rated to maintain 20bar pressurized line , after it opens and thats is job.
beware to install the DV body with the slot in the right place, and tight force should never exeed 18N , too much tight may cause rack malfunction and one may end up with a stuck rack.
Cheers, feel much reassured now.
Looking at a diagram I only removed the holder, teased out the copper washer and renewed it and fitted a new o ring to the holder and torqued back down as per the Mercedes work sheet (30nm, slacken, 30nm slacken then finally 35nm) so I didn't do anything with the actual grooved valve.
ok, we use 20nm, but that is not a problema, sometimes those values change from bosch to the car manufacturer....
the problema is that 30nm is nothing if u use a 1/2 inch wrench . and if the rack stucks it may stuck in starting position wich is 2/3 of travell and enough to destroy the engine.
Another thing that can happen if you apply too much torque is the sleeves can push out the guide pins and rotate. I had a pump in my hands the other day that had this problem. All of the sleeves were rotated approximately 90 degrees or so from the correct position and two cylinders would receive a big amount of fuel and the rest no fuel at all. I had to push the pins back in and reinstall the sleeves.
It's a good idea to take the rack cover off when changing the DV seals. After the valve holders are torqued down you must be able to move the rack and those pins must not be flush with the surface, if they're flush they've pushed out. They need to be recessed by about 1 mm.