identifying 12mm pump head

Alright.... I know how to check a pump pn to see if it's a 10 or 11 pump, but how does one go about identifying if a pump has had a 12mm head swapped out?

tia

exactly the same way. in the middle set of digits of the bosche PN, the middle number is the head size.

for example, an alh pump number looks like this:

0 460 414 997

that underlined 1 in the middle is the head size

full breakdown below, copied from vwdiesel.net and altered to match ALH pump

0= Denotes complete product
460= Product class, Distributor pump
4= Identifier for VE Injection pump
1= Plunger Diameter: 8=8mm,9=9mm,0=10mm,1=11mm,2=12mm etc
4= Number of Cylinders
997= Application

very nice breakdown of the part number, but not really what he was asking

blu_jet_92 said:

but how does one go about identifying if a pump has had a 12mm head swapped out?

Click to expand...

only options are unscrewing the three-flat endcap and measuring, or removing the head from the pump and measuring that way

Whoops, late night. Didn’t catch that.

I don’t have a pump in front of me, but I’m not sure what you are referring to with “three-flat endcap” when I look at googles images. I had no idea you could tell without removing the head.

Can you elaborate on that?

centered between the delivery valves
15/16" three flat dingus that you gotta cut up a socket to remove

Gotcha. All the pics I was looking at were side views or exploded diagrams so I wasn’t grasping that. Thanks.

bump....