3930 Radiator Drain Cock Missing?

[dapper]

Evening All,
Thought I would take advantage of the nice weather here today, do some maintenance I have been putting off till summers end, and clean up all my equipment. A couple of to-doe's for the 3930 were putting a new fuel filter on & changing out the antifreeze. Cleaned the sediment bowl, and got the new filter installed and bled with no problems. :thumbsup: So I continued on and checked the antifreeze. Fluid checked good, but don't know when it was put in, or changed, so thought I would just change it out and I would have record of when it was done. Should be simple drain and fill right??? OK!!! But wait! I cant find a drain cock for the radiator! Checked every place it should be, but no drain. Pull out the books and they show drain cock on left side of radiator at bottom. WRONG! Not on my tractor... Book did say that "some models may have drain cock in engine block instead". WRONG! Not my tractor!!!I do have a plug where the book shows a drain cock, but not sure if this is the correct plug or not. At this point I'm not confident enough to remove it. Even checked on NH website and they show a drain cock on left rear of radiator, right where the book says mine is located... WRONG!! I know I could just take off the lower radiator hose and do it that way, but thought I would ask the "experts" here what I was missing?? Should there be a drain cock somewhere, or do I need to change/drain by taking plug out of engine block? Is there somewhere else I should be looking?? Might have missed something/somewhere?
BTW: Book also stated that NH "inhibitor" should also be added at antifreeze change, so I will have to pick up some of that. My NH parts man LOVES me! :laughing:
Appreciate any input.

 

[RickB]

Complete coolant draining is accomplished by removing the 1/4" pipe plug in the block where the draincock is shown AND removing the lower radiator hose connection from the radiator. Most NH 30 series tractors left the factory with radiators without drain fittings and plugs in the blocks where a draincock should have been.

 

[dapper]

Thanks RickB.
Was afraid you would say that. Can I buy a drain cock from my local parts dept that will fit in the block where the plug is? After all, I have to see them for the inhibitor anyway. :laughing: What's a few more $$ right. :laughing:

 

[5030]

Not that I own a NH tractor but I'd leave well enough alone and remove the lower radiator hose and block plug over a drain cock because the radiator cock won't get all the stale antifreeze out and the hose/plug will. That's something I do with my equipment as SOP.

Far as inhibitor goes, instead of (I would assume pricey) NH stabilizer, a bottle of DCA4 or SCA precharged extended life antifreeze should be just fine.

 

[RickB]

A proper drain cock will drain just as much fliud as removing a plug, or close enough not to matter. Should be readily available in 1/4" NPTM.

 

[dapper]

5030,
I have not heard of DCA4, or SCA. Could you please explain further. Meanwhile I will do search.
Rick,
Thanks again. :thumbsup: I have checked and should be able to pick up drain cock at my local Fastenal store. Few $$ no big deal. To bad NH couldn't have added this at build. Not much more expensive than the 1/4 plug. Any advantage to the NH stabilizer? Or something over the counter from local farm store just as good?

 

[Redneck in training]

I would put the plug back and not use the petcock. It is safer. Petcock can be opened or broken off by accident. How often do you change the antifreeze?

 

[5030]

5030,
I have not heard of DCA4, or SCA. Could you please explain further. Meanwhile I will do search.
Rick,
Thanks again. :thumbsup: I have checked and should be able to pick up drain cock at my local Fastenal store. Few $$ no big deal. To bad NH couldn't have added this at build. Not much more expensive than the 1/4 plug. Any advantage to the NH stabilizer? Or something over the counter from local farm store just as good?

The 'stabilizer' that NH sells is most likely a SCA derivative as is DCA4 which is Cummins Engine brand of SCA. SCA is a stabilizing additive for wet linered engines to prevent cavitation of the cylinder liners but prevents solder bloom and ph unstability in parent bore (dry linered) diesel engines too. Actually I use it in all my water cooled engines, gas or diesel.

You can buy extended life SCA precharged, pre-diluted antifreeze as well. It's purple in color and will mix with normal green ethylene glycol. Extended Life orange or red will not mix with conventional green (ethylene or propolyene glycol) antifreeze. Mixing them causes the antifreeze to turn to sludge.

The easiest for me at least is to just add the DCA4 to the green stuff.

I would put the plug back and not use the petcock. It is safer. Petcock can be opened or broken off by accident. How often do you change the antifreeze?

I vote for the plug as well. Take the plug out and loosen the lower radiator hose clamp...takes a couple minutes.

You don't find petcocks on hydraulic tanks (on tractors) for a reason.....