Mk5 bosch pump wont turn

[powercrazymark]

I acquired a bosch 145 pump yesterday and it wont turn by hand. Is this right and does it take some force to turn it or do I need to strip this pump, fix and rebuild?
Thanks

[V184]

yes they are tight to turn

[powercrazymark]

Ok so I can turn it with a 22mm spanner. But it will only turn anticlockwise and it jumps around in sections rather than on fluid motion is this right?

[MinorMatt]

Yes that's right

[Chug]

It turns clockwise looking from the 22mm nut end, but it should turn in either direction and in four equal turns per one complete shaft revolution, each quarter turn moves over a hump in the camplate, which has four cams, or humps, one for each plunger/injection stroke.

[powercrazymark]

This seems to be the case chuggy however it just gets jammed if I try and turn it clockwise looking directly at the 22mm but anticlockwise seems fine.

[Chug]

Sounds like there is something amiss in the pump, removing the top cover may let you see what is going on.

[powercrazymark]

Is that the 4 Allen bolts?

[Chug]

Are you clamping the pump in a vice when you try to turn it?

yes the four allen bolts, the throttle idle adjustment screws need removing to get to rear right one, and with the throttle arm make sure to scribe a line to mark the postion to make sure it goes back in the correct position.

dsc05406.jpg

bosch stipdown vid look here https://www.youtube.com/watch?v=_01gEg2ZMwg
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[powercrazymark]

So I cleared the bench ready to stip the pump and just before I did i tried on last time at turning it clockwise and it turned. Now it turns both ways, but the other day it was definatly jammed clockwise. This pump has been sitting for a while so maybe it has just freed itself up by my tuning it a couple of times, or is it still worth the strip down?

[Chug]

It might be ok, it might not, it's your call as to whether you just fit it and hope for the best, or have the confidence and knowledge to strip and rebuild the pump.