Harbor Freight Compression Tester !!!Warning!!!

[speedracer815]

I just tried to use the "U.S. General" Diesel Compression Test Kit from Harbor Freight and wanted to warn you guys...

The adapter that they say will fit our engines does NOT. It's too long and bottoms out even before the threads engage. It also lacks the tapered seat that our glow plugs seal on, so I would presume if it did thread in it might damage the seat.

At $17 I'm thinking I'll keep it and pay another $15 (give or take) for the right adapter from another supplier.

[cdnsarguy]

Thanks for the heads up re the adapter.........there are adapters in some kits without tapered faces and they will work just fine as long as they are the right length.

[OkieGringo]

I posted a week or so ago that the adapter in that kit doesn't work in our engines. I guess you missed that one. You can order the glow plug adapter from www.starhoffman.com. The the adapter was $32.03 + $12.18 shipping. Adapter part #TU-15-22A The part that screws into the GP hole is attached to 6" of flexible hose and has a quick release coupling that will fit your new gauge. The flex makes getting around the steel lines real easy. OkieGringo

[tim94f250]

So, This adapter ends up costing you $45.00? That's pretty steep. I bought my comp. tester from Napa. The total was $125.00, but I have about 8-10 adapters in the kit and it fits about all makes of diesel engines.

[FraserScott]

I made my own adapter out of an old glow plug and a 3/8" pipe nipple. I put the old glow plug in a vise and with vise-grips i clamped onto the the bullet terminal twisted and pulled. Once the terminal was off I was able to tap out the carbon element. This left me with a hollow glow plug. I took the hollowed out glow plug to the bench grinder and groung the hex (where you put your socket for removal) round to fit tightly into the end of the 3/8" pipe nipple and silver soldered the two together. I was able to thread on the quick connect from a friends snap-on set and use the snap-on gage. I don't know how the Harbor-Freight one looks like but this worked for the snap-on gage. [img]/ubbthreads/images/graemlins/shrug.gif[/img]

[James Keveson]

I bought my glow plug adapter from www.tooldesk.com They are 10.00 bucks for just the adapter. you can also buy other adapters from them for other diesels. James K.

[nubiecanobie]

Hey Tim,

Which tester did you buy from NAPA with 8-10 adapters? I can't seem to find it at NapaOnline.

I gave up trying to make a glow plug adapter for my (home made) compression tester and bought the NAPA tester kit Item#: SER3468 Price: $108.89, which is suppose to work for Navistar 6.9 and 7.3 engines. BS!

http://www.napaonline.com/MasterPage...ression+Tester

There is no way the NAPA kit I bought will work in all 8 glow plugs without pulling the injector lines on my 88 E350 7.3

Cyl 1 & 2 was not too bad and I got readings of 460 & 450 respectively (done cold as test run only). Cyl 3 was much more difficult. 4 I couldn't get the right angle coupler onto the adapter, interference, physically impossible. I think the only hope in getting to the rest of them withour pulling injector lines is with the TU-15-22A flex adapter that Okiegringo mentioned.

http://www.aeincorporated.com/Star/?..._to_display=50
Diesel Adapter M10-1.00 Glow Plug- Ford/Navistar

Should I pull the injector lines to finish the compression test or is that another can of worms waiting? Any special tools I need? Should I just buy a flex adapter so that I do not have to pull the injection lines? It has not been fun so far with all the effort and not making much progress.

[ QUOTE ]
So, This adapter ends up costing you $45.00? That's pretty steep. I bought my comp. tester from Napa. The total was $125.00, but I have about 8-10 adapters in the kit and it fits about all makes of diesel engines.

[/ QUOTE ]

[tim94f250]

That isn't the one I have. But, if you read the description on the page, it lists 10 different types of engines that it fits. Mine cost about $135 or so, but mine has more adapters. My tester is also not close by, so I can't get the part# until tomorrow. When I have it, I will post it. Tim

[nubiecanobie]

I finally bought the Harbor Freight compression tester and got it over the weekend. What a bargain at $19.95! The quality is excellent also. Took a compression reading in my car (all cyl's 460 psi !!!) and it worked very nicely. The right angle adapter provided made a hard to reach glow plug hole possible.

As far as using it on the 7.3 IDI, the long glow plug adapter looks too long when layed next to a glow plug but there is a real short adapter (the #10 one) that may work. If not, a flexi adapter has to be made. I will try it out in my 7.3 a few days and let you know.

One more thing. The quick coupler used is different than the NAPA kit that's made by KD so don't bother trying to buy a flex adapter from them for the Harbor Freight kit.

Don't drop any of the fittings and adapters into the engine compartment. They are chrome plated brass and a magnetic pickup wont't work! Ask me how I know. DOH!