Compression tester purchase recommendations/questions
 

Hi all,

I'm looking to buy a compression tester for my 84 and 87 300D's (OM617 & OM603). There are two different size adapters for the injector holes. According to Baum Tools:

Early MB = 24mm x 2.0mm
Late MB = 22mm x 1.5mm (not a common adapter, apparantly...)


I know the 24mm one will work with the OM617, but I'm not positive about the OM603. From what I can tell, the early OM603's (86/87) use the early adapter, and have the "pin" locknut for the prechambers. The later (90-up) 602, 603, and 606 engines use the "splined" locknut, and I'm guessing the 22mm adapter. Does anyone know for sure?



Also, the URL below had what looked like the best deals, at least the best I could find. Any comments on the vendor and/or tool manufacturer (Star-Hoffman)? Any better prices, mfr's, or vendors?


http://tooldesk.com/cgi-bin/webplus.exe?script=/shop/group.wml&deptid=Diagnostics%2FTesting&deptname=Compression%20Testing%20&storeid=1&groupid=Compressi on&SessionID=200213111324208

$95, ATD kit with 7 (?) adapters & case - ATD-5680
$34, ATD "by Hoffman" gauge only - ATD-5560
$12, ATD "by Hoffman" adapter only - ATD-5562

(The adapter is the 24mm, btw, separately or in the kit.)



Thanks! :-)

Dave:

I own a diesel compression tester made by Tool Aid that has 3 adapters that fit M-B diesel engines:

Glow plugs:
early loop-style 18mm x 1.50
late pencil-type 12mm x 1.25

Injector nozzle:
24mm x 2.00

Your engines should use the pencil-type glow plug adapter, 12mm x 1.25. You can use the 24mm injector nozzle adapter, but that is more work because you will need to the tools necessary to remove the injector nozzles (27mm deep socket) and the hard fuel line special tool that's like a flare nut wrench, torque the nozzles when installing them, bleed the fuel system, etc., etc. Using the glow plug adapter is much easier. All you have to do is remove the glow plugs, shut off the fuel delivery at the injection pump (using the manual shut-off on the 617 engine, I don't know about your 603) to prevent fuel from being injected while cranking the engine to test compression, do the compression test, and then re-install the glow plugs when the test is done.

The Tool Aid kit comes with the gauge and 5 adpaters with instructions in a case for $110.64 with free shipping from Ontool.com. On Tool sells a lot of automotive tools and equipment and has good support with generous -free to ask questions about their tools. return/warranty policies. You can call them toll I have a few other Tool Aid tools and they make quality tools.

On Tool also has the Star compression tester for $104, but the kit says it has adapters for domestic engines. However, the 24mmx2.00, 18mmx1.50, and 12mmx1.25 adapters fit many domestic engines as well - so you will need to check to see if the Star tester has adapters to fit your engines.

The ATD compression tester you are looking at looks like a good tool and price, but I have no experience with this tool or the company selling it.

Also, your link does not work. I had to use my search function to go to the Tool Desk site - just thought you would want to know.

Good Luck!
Tom

Thanks, I'll check that out. I also fixed the URL (sorry about that!)

The glow plugs on the OM603 are a major PITA to access, it actually might be easier to pull the injectors! I'll check into that as well.

Thanks again,

check out this thread...