Should I check compression/leakdown via glow plug holes or injector holes?

[JohnDB]

Hi all - thinking of getting a compression and leakdown test on my S2600 engine so need to remove glow plugs or injectors.

Question: which is less risky? Remove glow plugs, or remove injectors? (People with the same series engines - Z751 Z851 DH1101 D1301 V1501 V1701 S2200 S2800 may know the answer to this).

• Removing glow plugs sounds simpler but are they prone to breaking on these engines? Do I have to pull the cylinder head off if a glow tip plug breaks?
• Removing injectors - need the special tool with a slot cut out for the return lines - I can easily make the tool myself, but do I have to first loosen the nut that holds the "eye tube joint"? In which case I'm disturbing the copper washer, so I would need to pull the injector body apart and anneal the copper washer. (In addition to removing the fuel lines to the injectors - risk of dirt getting into lines or injector etc.)
• I believe some glow plugs are hard to get at - so maybe it would be less grief to remove the injector on those cylinders. Would it affect the results if say one cylinder was tested via the injector, the rest tested via the glow plug holes?

Would be great to get your opinions, thank you.

 

[thepumpguysc]

Glow plug hole..is by far less invasive.. Jut take your time & go slow.. make sure the angle on your socket is straight & not over to 1 side.. once u get the gp loose, twist & pull up SEVERAL times to knock off any carbon build up.. it'll come out 99% of the time..
If using the inj. hole.. u have to remove the return line rail which means new gaskets, remove the injector which means new gaskets or ALOT of "sanding"..Then torqueing the inj. back in the head.. THEN if u didn't do a good job sanding, u have to do it all over again.. it will leak compression.. THEN u have to find an adaptor to take the place of the inj. to attach to the gauge..
USE THE GP HOLE..
WHY do u want a compression test??

 

[D2Cat]

If your GP's work they won't have carbon build up on them. On some engines it's easier to remove the intake manifold to get to the GP's, and that's an easy job.

 

[JohnDB]

Thanks for those answers, really appreciate your thoughts.

The glow plugs do work OK (or at least enough of them do to start it... manual recommends 25 seconds activating the glow plugs, and then it usually starts first time). Our ambient temperature isn't very cold, worst is a few degrees below freezing.

I'm wanting to do a compression test or leakdown test because I'm not sure the engine is running as smoothly as it should. Checked the valve lash, the compression release isn't interfering, fuel and all filters recently changed. The tractor overall is in very good nick (5000 hours, mostly garaged) but a lot of ancilliary things (loader, front rims, lights, fenders) could do with tidying up. If the engine's good then I'll do up those parts, but if it's not then I won't (and I'll still love her even if she is a bit tatty).

Really enjoy reading this forum.

 

[lugbolt]

All the kubota's I've dealt with are FAR easier to check through the glow plugs. Only suggestion, though, turn the fuel off, somehow disable it from being able to start. If you don't, it'll run with the compression gauge in the hole which throws your compression reading way off.....

 

[thepumpguysc]

hahaha.. I forgot about THAT.. Yes, disable the shut off solenoid.. or pull the stop cable, which ever u have..

 

[JohnDB]

...Only suggestion, though, turn the fuel off, somehow disable it from being able to start. If you don't, it'll run with the compression gauge in the hole which throws your compression reading way off.....

Fantastic, you guys. I can imagine it....