The pop testers available on amazon have less than stellar ratings, ditto for Ebay. Alibaba offers up made in china. I stopped by NAPA and asked, no joy. Any ideas?

I found my Bosch pop tester on CL from a retired diesel mechanic. Only other place I know is Mercedes Source. They make their own out if bottle jacks. I have no idea about the quality.

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CENSORED due to not family friendly words

You're best building one from scratch if quality is a concern, that way you can control the quality haha...I was building one but abandoned the project. I used an oil/grease gun btw

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1998 Ford Escort ZX2 5 speed - 279,000 miles My Daily

1992 Mercedes 300D 2.5 202,000 - Pure junk
2000 Mercedes E320 Black - 136,000 miles - Needs repair

Don't forget to grease the screw and threads on the spring compressor.

I made the 10 ton hydraulic ram version. The power and extra stroke is awesome as you can make extra long high pressured sprays to clean the nozzle out if you want. Liquid filled 3K gauge, high pressure steel fittings and a vw injector line.
I'll sell you mine, recently used it so I know it's working good. I never made a vertical filter set up though, just tilt the pump up and fill it with filtered diesel. It looks kinda like this one Another Home Made Injector Pop Tester

I'll make another one next time I need to do injectors.

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1985 300TD 1981 Scirocco 1.6D conv 1986 Golf 1.6D 2003 Golf TDI

If you don't like the bottle jack type, make your own. I have one which looks like the link in post #4. The pump was for testing Ford diesel devices and came w/ a remote reservoir. Search my post for PN's and photos.

I recently acquired parts to make another, based on an Italian hydraulic hand pump I got cheap on ebay (~$20) and same McMaster-Carr fittings. I may post when done, and no plans to sell.

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1984 & 1985 CA 300D's
1964 & 65 Mopar's - Valiant, Dart, Newport
1996 & 2002 Chrysler minivans

I had to replace the gauge because it went to 8K psi. I reckoned having one which was rated at that pressure and on that scale would be good. I put a 3K gauge on it and it works perfectly.

If I added a shim of a particular thickness I'd get a particular increase in pressure to reach the popping point. That remained consistent throughout the injector(s) rebuild.

I'm obsessive when it comes to details so I lapped my injector bodies to make minute adjustment when shims were too thick. I got all 5 injectors popping at exactly 1975psi. I do not believe that could be done without a quality pump and gauge.

I think this is the one I bought.

https://www.ebay.com/itm/Diesel-Injector-Nozzle-Tester-Pop-Pressure-Tester-Dual-Scale-600-8000-PSI-BAR/112480927218?hash=item1a3062bdf2:gIYAAOSwpoNal6Wr

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84 300SD
85 380SE
83 528e
95 318ic

Instead of replacing shims I just sand the existing one to drop the pressure or sand the housing to increase pressure.

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CENSORED due to not family friendly words

Usually all you might need, if any, is .1 or .2 mm shim.

I wouldn't want to sand a lot on the injector housing; then have to take it all the way down to at least 2000 grit and hope it doesn't leak. If you have to increase it 200psi, probably want a shim for that.

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1985 300TD 1981 Scirocco 1.6D conv 1986 Golf 1.6D 2003 Golf TDI

If build something like the link below, is there any danger it could exert too much pressure on the nozzles?

Another Home Made Injector Pop Tester

I wasn't suggesting that lapping increased popping pressure more than the value achieved by adding a 1 mm shim. My goal wasn't to get nozzles to pop at any pressure within a 'window,' of pressure, I wanted an exact pop pressure in all five nozzles.

Lapping injector bodies prevents leaking if it is done correctly. I seem to remember a 1 mm shim increased popping pressure by ~35 psi. When an injector popped lower than my target pressure but within 35 psi I lapped the bodies enough to achieve the difference. None of them leak.

I think I started the lapping with 1200 grit then used 2000 grit paper to polish.

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84 300SD
85 380SE
83 528e
95 318ic

I understand. It is good to know that sanding does change pop pressure; Just wouldn't want anybody else to get the wrong idea about the amount of sanding it takes to change pop pressures - especially since shims can be hard to source.

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1985 300TD 1981 Scirocco 1.6D conv 1986 Golf 1.6D 2003 Golf TDI

This is how I've always done it on my om603 and om606. I only use 2000grit. It really doesn't take very much sanding to change the pressure by 200psi. I also measure the injector housing halves and interchange them to change the pressure. And I accumulated a stash of spare injectors and shims to swap if need be.

When installing new nozzles it's important to pull the injectors after 1000 miles and rechecking the pressure. Some nozzles
will drop the pop pressure by 100 or 200 psi when they are broken in.

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CENSORED due to not family friendly words

I bought a bunch of various size shims from the U.K. a few years back before starting a injector rebuild so I guess I never had to find another way.

Good reminder on the 1000 mile check - another great reason to have a pop tester. Where I live the "diesel" shop doesn't do pop testing - they send them off to the big city an hour away. After finding out what that costs, I built one.

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1985 300TD 1981 Scirocco 1.6D conv 1986 Golf 1.6D 2003 Golf TDI

I built mine out of a cheap portapower style hydraulic ram pump from amazon, and a bunch of fittings from mcmaster-carr.

Probably around $80-100 for all the parts.
$40-50 for the pump
around 20 for the gauge, 0-3000psi liquid filled (there is debate on filled vs non-filled gauges. I went for liquid filled, and I like it)
maybe 10-20 in fittings and an old injector line.

Waaaay better than the bottle jack style I had before.
No need to bolt the thing to a bench, long handle makes pumping easy, more intuitive pressure relief for switching injectors, and has a pre threaded 1/8 npt hole for the diesel supply/refill (I plumbed mine to a little container of diesel)

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1982 300D (w123, "Grey Car")
1982 300D (w123, "Blue Car")
2001 Ford F150 "Clifford" (The Big Red Truck)
1997 Dodge Ram 2500 12V Cummins
1996 Dodge Ram 2500 12V Cummins
Previous Vehicles:
1995 E300D, 1980 300SD, 1992 Buick Century, 2005 Saturn Ion

I also posted McMaster-Carr PN's for shims. I only used the 0.1 mm thick ones, which increases pop pressure ~100 psi. I think +/-50 psi is sufficient, since hard to measure much closer and it will change over time anyway.

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1984 & 1985 CA 300D's
1964 & 65 Mopar's - Valiant, Dart, Newport
1996 & 2002 Chrysler minivans