Perkins 4108 Compression Tester

[Kevin Spacebag]

Anyone have any suggestions as to where I can find a compression tester with a proper adapter for the 4108? I’ve seen a few oblique references to bolt-on rather than threaded compression test tools, but nobody has been able to point me in the right direction.

Thanks!

[marcjsmith]

might need to find an old injector and modify it to become your adapter.

[Oohla]

Amazon has compression test kits with multiple adaptors, some for the glow plugs, some for the injectors. Mix and match.

[marcjsmith]

the 4108 has a smooth bore injector with two bolts and yoke that hold it down... and no glow plug.

[alaskanviking]

There's a guy on eBay that sells an aluminum piece to compression test a 4-108. $20 I think.

Threaded on one side to fit a quick disconnect fitting like what's used in the Amazon or harbor freight tool kit. You use the hold down bracket from an old injector.

I also borrowed a home made one from an injector shop. They gutted an old injector and welded on a air quick disconnect fitting.

Key to both of these is having copper injector gaskets available. I didn't get the warm fuzzy that the tests were replicatable when I borrowed the diy tester. Learned a lot over the years and fairly certain it wasn't sealed well. Something I will address when I do it next. I keep adding the ebay one to the cart but other priorities keep bumping it.

https://www.ebay.com/itm/Perkins-Wes...-127632-2357-0

[Niall leslie]

FYI
- The manufacturer of your diesel compression tester will likely be able to supply the various adaptors. ( NB - For non technicians, a diesel engine compression tester is different to a gasoline engine compression tester due the the different pressures involved. ) Failing that, likely Snap - On for a complete tester. Alternatively any competent machine shop could machine one for you.

- You may find that a leak down tester would be of greater to use to you providing that you have the skills to interpret the results.

Cheers,

Niall.

PS - The cost of all of the above covering a range of engines etc. is one of the reasons that technicians cost what they do.
If i can find the manufacturer of my tester I'll post again later.

[Cheechako]

We had to make one for my 4-236. Even the mechanic didn't have one. They discounted the time to make it if they could keep it after.

On diesels the gauge cannot be hand held for good testing.

[Niall leslie]

FYI,

Snap - On, OTC and Lincoln Tools all make kits.

NB If you're not familiar with the usage though it may be better in the long run by getting a good marine diesel technician to do the testing for you so that they can correctly interpret the results.

Cheers,

Niall.

[cr180]

If your engine is in running condition, a good indication of Perkins compression is how it starts. My experience is that a Perkins in good condition should start immediately. Had two mechanics confirm that immediate starting an indication of good compression.