Bosch Pop Off Tester 0681200502

[Turbo300Mercede]

My Bosch Injector Tester, 0681200502, 4910-12-121-2844 has become stuck from sitting with diesel fuel in it.

Has anyone ever taken one of these apart or have a service manual with an exploded view that shows how it goes together?

Last time I used it I rebuilt some injectors for my 240D with Monark Nozzles. But that has been a few years. Never thought the diesel fuel would cause it to seize.

I have tried Kroil penetrant and a heat gun along with careful tapping of the element that the lever compresses, to no avail.

Thanks!

[Turbo300Mercede]

I recently had to tear down and clean my Bosch Pop Off Tester. Here I have documented the work for anyone with a similar issue. The piston within the tester was frozen at the top of it's travel. I could not find a repair manual, so I thought I would place this here to show how it comes apart.
Slides 1 to 5 shown here.

[Turbo300Mercede]

Slides 6 to 10 shown here

[Turbo300Mercede]

Final slides 11 to 13 here.

[Diesel911]

Originally Posted by Turbo300Mercede

My Bosch Injector Tester, 0681200502, 4910-12-121-2844 has become stuck from sitting with diesel fuel in it.

Has anyone ever taken one of these apart or have a service manual with an exploded view that shows how it goes together?

Last time I used it I rebuilt some injectors for my 240D with Monark Nozzles. But that has been a few years. Never thought the diesel fuel would cause it to seize.

I have tried Kroil penetrant and a heat gun along with careful tapping of the element that the lever compresses, to no avail.

Thanks!

With a brass or aluminum punch?

[Turbo300Mercede]

I used an aluminum drift I made to break it loose. See the pictures I posted above. One of them details that.

[Diesel911]

Originally Posted by Turbo300Mercede

I used an aluminum drift I made to break it loose. See the pictures I posted above. One of them details that.

I am on a different computer and internet setup so I can easily look at the attached pics now. But, not previously.

[cornemuse]

I dont know about the Bosch unit, but I have an old (USN WWII?) Bacharach nozzle tester, I use deez when I test(ed) nozzles, then emptied it & added "calibrating" fluid & pumped it through the tester. This fluid is like super high quality doesnt break down deez. Does not gum up over long periods of time. Expensive tho. ($15-$20 quart as I recall)
Diesel rebuilders leave this stuff in governers/nozzles & can then leave these items on the shelf for long periods of time.

[greazzer]

I got two of these. Total junk IMO. Didn't even last a weekend. Re-ordered parts, which did show up free of charge. Installed, and tinkered with it and no dice. Leaks, and other headaches. I woud not invest a lot of time. The Bosch clones are junk from my limited experience. Wasted money on two of these. Second one had replacement parts, which did not help at all. First one lasted maybe a week +. Second one a weekend, which as noted, I did get free parts, but that wasn't really helpful.