anyone know how to use a diesel pop tester? - Page 2 - PeachParts Mercedes-Benz Forum

biobenz617 · #16 03-17-2006, 01:22 PM

Quote:

Originally Posted by sailor15015

Would you guys mind explaining how you made those wonderful devices? I'd really love to be able to set my own injectors. That way I know I've got them right.

Check out this post for the BOM of the bottle jack style: http://www.peachparts.com/shopforum/showthread.php?t=130074&highlight=NPT+metric (#10). Note that there is a high pressure 3/4" x 1/4" NPT reducer bushing available from McMaster that will simplify the 3/4 x 1/2 and 1/2 x 1/4 reducer bushings. Not too difficult, but I did have access to a lathe for drilling and tapping the bottle jack for the 3/4" reducer bushing.

The jack is disassembled by removing the large hollow nut which the ram passes through, and the ram discarded. The ram seal is discarded from the large top nut, and the top nut hole is enlarged for the 3/4" NPT threads. The nut also has a relief hole which must be tapped and plugged with a set screw using JB weld. The inside pipe where the ram slides up and down also had a small pinhole in the threaded region, which I MIG welded from the inside ...probably could just slap some JB weld on it too (from the inside only!). I also drilled and tapped the external jack fill hole (previously plugged with a rubber stopper) so that I could JB weld a 1/8" NPT fitting for a reservoir to add biodiesel during testing. Reassemble the jack using JB weld between the top nut and the inside pipe threads, and also use JB weld for the 3/4" NPT joint, since there isn't much contact area inside the nut for the reducer bushing.

I still am trying to stop the leaks at the other NPT joints where I used non-permanent sealant.

I'll post some pics of my own so you can see how it goes together...

biobenz617 · #17 03-17-2006, 06:54 PM

...here is my tester. Unfortunately, I was just testing it and I noticed another leak. I think i cracked the nut on the jack somehow

Under pressure, it is squirting a fountain of diesel from a small fracture on the side of the nut. I might just scrap this heap and buy one on eBay.

dannym · #18 03-17-2006, 08:23 PM

The bottle jack would probably be better but for simplicity the grease gun works pretty good.
The only thing I needed from McMaster was a NPT to metric fitting to attach the used stock fuel line that I am using. I can't remember what the sizes were. If I remember I'll post it.

There was a 3/4 to 1/8 bushing that I found at home depot. Just remember to use all high pressure fittings.

I found my old order the metric fitting is 6mm tube OD to 1/8 NPT. part #5269k311
Here's the whole thing:

1 5269K311 General Purpose Steel Metric Tube Fitting, Male Straight Adapter For 6 Mm Tube Od, 1/8" Npt
1 each shipped.
1 each
2 50925K244 Compact Extreme-Pressure Steel Thrd Fitting, 1/2" Pipe, Tee, 3000 Max Psi
1 each shipped on Shipment 1. (See above) 1 each
3 4513K345 Hi-Pressure Forged Blk Stl Thrd Pipe Fitting, 1/2" X 3/8" Pipe Size, Hex Bushing, 3000 Psi
2 each shipped on Shipment 1. (See above) 2 each

Danny

sailor15015 · #19 03-18-2006, 03:44 PM

Quote:

Originally Posted by biobenz617

The ram seal is discarded from the large top nut, and the top nut hole is enlarged for the 3/4" NPT threads

Does this mean that I have to have a way to tap threads on the inside of the ram chamber or are there already threads there to accept the fitting? I can make it if I don't need tools to tap threads.

dannym · #20 03-18-2006, 08:00 PM

There are no existing threads on a bottle jack. If you want to go this way you will need to thread it yourself.

Danny

sailor15015 · #21 03-18-2006, 09:45 PM

Ok well I guess that way's out. I'm going to give your grease gun idea a shot. Any advice or tips on making it would be greatly appreciated.

Hit Man X · #22 03-19-2006, 12:14 AM

Heck, this seems interesting. Is the grease gun easier to modify to make a pop-tester? I have a bunch of injectors I'd like to clean + balance for myself. Basically take the best ones. I like BruceMcC's setup.

How difficult is it to disassemble the injectors?

Can I purchase the shims to adjust the pressure?

What about increasing pop pressure?

Thanks

sailor15015 · #23 03-19-2006, 12:40 AM

Taking the injectors apart is easy. If you look closely at one you can tell where it comes apart. As for shims, when the thread by Kerma about the nozzles his company sells was being kicked around, he mentioned that usdiesel.com sells shims. You have to have them email you a parts list so I haven't checked it out yet. And yes anyone who's made a grease gun tester please share your knowledge.

Hit Man X · #24 03-19-2006, 12:44 AM

Yeah, dur... I just looked at one. Should be a snap to disassemble. I have this hardcore cleaning agent from Berryman, this stuff will eat the paint off your car quick. I plan to soak the injectors in that after taking them apart prior to cleaning.

Hell, that place is just up the street in Ft Worth.

sailor15015 · #25 03-19-2006, 12:47 AM

Yeah I used carb-cleaner on mine then my mom's virgin cooking oil on them during re-assembly. I had one that, as soon as it loosened a quarter turn, some funky yellow stuff came oozing out. It looked like someone had tried to use some kind of sealant.

Good thing it didn't work its way into the injector.

Hit Man X · #26 03-19-2006, 12:50 AM

Okay I emailed them for the list, I'll hear back soon I hope. Also hopefully I can get the parts to reseal the SDLs IP or have it done there.

dannym · #27 03-19-2006, 09:17 AM

Quote:

Originally Posted by sailor15015

Taking the injectors apart is easy. If you look closely at one you can tell where it comes apart. As for shims, when the thread by Kerma about the nozzles his company sells was being kicked around, he mentioned that usdiesel.com sells shims. You have to have them email you a parts list so I haven't checked it out yet. And yes anyone who's made a grease gun tester please share your knowledge.

If you look at the picture in post #6 and my part list in post #18 it's not very hard at all.
one (1) high pressure Tee 1/2"
three (3) 1/2 to 3/8 npt bushings
one (1) metric fitting adapter
one (1) old fuel line
one (1) pressure gauge
one (1) mouinting board
Make sure you use all high pressure hardware.

If you can find a 3/8 Tee you can do without the bushings.

Screw bushings into Tee.
Screw pressure gauge into top
Screw grease fitting into bottom
Screw metric adapter into side.
Mount it all onto the board making sure the grease line is tight on the fitting.

Doesn't get any easier.

Cleaning and testing instructions can be found in the on-line FSM.

Kerma did post a link for shims or you can contact the Robert Bosch Corporation for a local authorized dealer near you:

Robert Bosch Corporation
2800 S. 25th Avenue
Broadview, Illinois 60155
(708) 865-5200

Danny

biobenz617 · #28 03-22-2006, 01:37 AM

This weekend I welded the top nut to stop the leak and was able to test

So, what is the spray pattern really supposed to look like? The factory shop manual shows a perfect stream, but is that really what is usually produced? All 5 injectors are spraying a conical pattern opened about 10-15° as shown while using B100. Is this acceptable?

I tore them apart about 2k mi ago for thorough cleaning, but wasn't able to test them. I'm not sure if they are original, but the engine has 265,000 on it.

sailor15015 · #29 03-25-2006, 09:28 PM

Quote:

Originally Posted by Hit Man X

Okay I emailed them for the list, I'll hear back soon I hope. Also hopefully I can get the parts to reseal the SDLs IP or have it done there.

Did you ever hear back from them?

Also does anyone know if those are acceptable spray patterns that are shown? It looks good to me but I have know idea what to look for.

Hit Man X · #30 03-26-2006, 04:31 AM

Still not yet, I will probably call them.

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