Diesel compression tester

[Muir hill 101]

What kind of compression tester do you guys have ?

 

[Dieseltech]

I have two, an old Bacharach set with adapters and a newer Snap On set for glow plug engines.

 

[Welding man]

Two Snap-on's with lots of adapters.

 

[kurt:in]

An old Mac and adapters.

 

[Robert (ID)]

one like this and lots of homemade adapters
poke here

 

[Butch(OH)]

I have a set that came came from Harbor Freight 15 years ago or more. Bought it mainly because it has tons of adapters that have fit anything I have ever needed it for. Guage ended up being right on calibration so I never replaced it. Not sure if they still carry it.

 

[Muir hill 101]

Will it fit John Deere pencil injectors ?

 

[Dieseltech]

Nope, I don't see the pencil injector adapter in that set like the Bacharach set has.

 

[Indiana George]

How do you do a compression test on a diesel ? I have a 885 david brown

 

[Destroked 450]

I ve had a Snap On compression tester with a 885 Cummins adapter for many years
Wanted adapters for Ford tractors, 5.9 and 8.3 Cummins
Picked up a Harbor Freight tester with a bunch of adapters for less than the 2 Snap On adapters cost
Pretty sure there s one for JD in the set

 

[Dieseltech]

All injectors removed, then the right adapter is bolted into the cylinder head in place of injector and gage connected to the adapter. Then I usually crank engine ten puffs and read the gage. Repeat on each cylinder injector bore. Make sure battery/starter are in good shape before the test, as low cranking speed will not give accurate readings.

 

[Indiana George]

Thank you dieseltech

 

[rlp in Co.]

How much pressure should a diesel have?

 

[Muir hill 101]

Specs on a 4270 Deere is 450 to 475 at 1000 feet elevation

 

[Muir hill 101]

For now i may just gut a pencil injector and weld a cap to the top need to figure out a valve that I can release the pressure though

 

[Muir hill 101]

Id really like a snap on set

 

[Dieseltech]

All my adapters have a Schrader valve in them.

 

[Dieseltech]

Usually the minimum spec is 300 PSI, but diesels don't start well cold when that low. I like to see at least 350-400 PSI on direct injected engines, most glow plug engines with 22/23-1 compression ratio will be 450-500 PSI. Diesels will run well HOT with just 275 PSI, but are VERY HARD to start when cold.

 

[rlp in Co.]

Thanks

 

[Muir hill 101]

Can you post pictures of your adapters ? Would a brass needle valve work