Diesel Leakdown Tester?

[trbankii]

Found a couple threads about compression/leakdown testing. What leakdown testers do people recommend? One post had a link to a Matco unit, but the link was broken.

Is it basically the same unit as for a gasser? I just need the proper adapter to use with the glow plug hole?

[BobND]

I recently did leakdown checks on a couple of 6.2's using a friend's "Aircraft Tool Supply" leakdown tester, used along with the glowplug port adapter from my diesel compression tester. It is, of course, necessary to remove the valve core (check valve) from the compression tester's glow plug adapter.

(It would be simple enough to "gut out" and old glow plug, braze a coupling to it, and make a "dedicated" glow plug port adapter for the leakdown tester.)

Incidently, the leakdown results on the 6.2's were TERRIBLE, at least compared to any "gasser" I've ever checked, and one is a pretty good running engine, and does not use an inordinate amount of oil. I'm not posting the numbers, as I think cylinder leakdown testers give kind of relative results, that will vary from tester to tester (the readings are taken on 2 gauges, one on either side of a fixed oriface, and AFAIK, this oriface size is not standard, but will vary from one mfgr's tester to another mfgr's tester), so readings will vary, but will still show the relative leakdown between one cylinder and another.

Also, unless you have the piston at EXACT TDC, the air pressure from the tester will push the piston down,into the less-worn area of the bore, giving better (but FALSE) readings than at TDC.

[Kennedy]

I have a Moroso single gauge unit at the recommendation of my machinist for a simple, direct reading gauge. Never did look into adapters for a diesel though.