On the models that do not have a Hand Primer the Pressure Relief/Overflow Valve is different and has a tiny hole to bleed the Air out and maybe the Lift/Fuel Supply Pump puts out more Volume so it bleeds fast.

The Pressure Relief/Overvlow Valve on the 617s simply has a spring and a Ball Bearing that acts as the Valve.

Past experience whith those inline Rubber Squeeze Bulb type Hand Primers on Diesel Engines have them leaking within a year or 2.

Increasing the Lift/Fuel Supply Pump pressure by putting in a heavier spring means the Cam iside of the Fuel Injection Pump will be stressed a little more.

You do need to be careful what Epoxys you use. Look for ones that have a working temp of up to 250 degrees F. JB Weld and Duro are ones I have used with no issues.

In particular I have found that the Fast Set types are not good for Automotive use were there is heat involved.

Marine SQUEEZE TYPE PRIMER BULB
 

GP,

The product you're looking for is retailed by a Marine Supplier named Moeller.
I've spoken with them and they assure me the product is not affected by Bio-Diesel.
I have one,to install in the incoming fuel line (Between the Primary and the
lift pump) on my OM602.

One Supplier:

http://boatingsavings.sportsmansguide.com/net/cb/Moeller-Primer-Bulb-5-16.aspx?a=622922&kwtid=515050&pm2d=CSE-BSV-1-SHOPPING

just for informational purposes, the primer pumps can be bought from any Mack Trucks dealership. I believe they are the same. They are genuine bosch and still only run about $10.

Don't epoxy the hole over, take the pump in to a hydraulic specialist so they can measure it and have them order a plug to fit in place.

The 5 min epoxy's like JB Qwik are rated to 300F where the longer set (6 hrs) ones are 500F. That said I've been using the 5 min stuff in contact with diesel fuel with no problems. Since JB Qwik has been so successful, Loctite recently put out a competing product that is cheaper and claimed to be stronger called Epoxy Weld

http://www.loctiteproducts.com/p/epxy_weld_t/overview/Loctite-Epoxy-Weld-Bonding-Compound.htm

Lowes has it for $3.99 where JB Qwik is $4.99 or higher everywhere . I've been using it lately and I like it better than JB Qwik.

If you are in Germany maybe you'll be able to order a plug for it but good luck here in the US. That thread is different than the banjo fittings and likely not a standard metric thread.

I have the plug I made from the old primer pump installed and there is no more fuel seepage there but I still have an air leak. I'll just have to keep plugging away at it.

This seems to be much ado about nothing. My SD usually starts easily & runs with no problem. There have been a few times where a quick pump on the primer has been needed. The primer worked & I was on my way. Why waste effort fixing something that normally works and is a cheap easy fix when it doesn't work? Replace the primer if it leaks. No need to go around the world to cross the street.