[Sentoa] Draining Cummins 5.9 engine coolant

Charles E. Billings ceb at oz.net
Wed Jan 23 19:51:26 EST 2013

Hi Jim,

I’d be happy to snap a few photos the next time I’m at the tug.   I’ll
also check my Cummins owner’s manual as well as my “parts manual” for a
possible depiction of the location on one of the engine drawings.

I’m currently recuperating from over a week long bout with viral
bronchitis (not the flu) so it’ll be a few days before I get down to the

Charlie Billings

NOBSKA, 32-057

Bremerton YC, WA


-----Original Message-----
From: Sentoa [mailto:sentoa-bounces at lists.sentoa.org] On Behalf Of
tugs4me at comcast.net
Sent: Wednesday, January 23, 2013 2:31 PM
To: South East Nordic Tugs Owners' Association (SENTOA)
Subject: Re: [Sentoa] Draining cummins 5.9 engine coolant



I'm not at the boat right now so can't check the Cummins manual for the
port you mentioned.  Sounds like a very helpful hint.  Any chance you could
get a photo (or photos) and send it to Herb for posting on the SENTOA site?

I've used the petcock in the brass coolant elbow just below the heat
exchanger and am able to drain 5-6 gal, enough to work on the system but
don't know if I've drained the block completely.

Jim Moore
RILEY 37085  


From: "Charles E. Billings" <ceb at oz.net>
To: "South East Nordic Tugs Owners' Association (SENTOA)"
<sentoa at lists.sentoa.org>
Sent: Wednesday, January 23, 2013 2:14:25 PM
Subject: [Sentoa] Draining cummins 5.9 engine coolant

This may not apply to all Cummins engines, but draining the coolant from my
1991 Cummins 5.9 is a piece of cake.   I don’t know if this is factory
spec or added by one of the two previous owners of my tug, but about half
to two-thirds of the way aft and low on the starboard side of the engine
block there is a port in the block to which is attached a rubber hose about
two feet long.   At the end of the hose is a ball valve fixture that allows
me to drain the entire engine of coolant.   All I have to do is loosen the
filler cap so there is no vacuum in the system, open the ball valve and I
have coolant flow into empty one gallon milk jugs to collect the coolant.
Being able to easily control the flow into the milk jugs is wonderful.   We
have a recycle station here at the club, so I’m able to dispose of used
coolant (and oil) whenever necessary.


It just occurred to me that while I can position the jugs lower than the
drain port on the side of the engine, some tugs with fancy engine room
flooring or different configurations may not be able to do that.   My
thought is if you can’t get the jug lower than the output port on the side
of the engine (gravity doesn’t work up hill), just purchase a second
filler cap to which you’ve attached a fitting that will accept the air
flow from a 12V air compressor or perhaps your high volume/low pressure
inflatable dinghy pump.   Once you’ve placed the hose in the jug, turn on
the pump to force the coolant liquid out of the engine.   (Be sure to block
the overflow vent to the plastic expansion reservoir.)


Charlie Billings

NOBSKA, 32-057

Bremerton YC, WA



-----Original Message-----
From: Sentoa [mailto:sentoa-bounces at lists.sentoa.org] On Behalf Of Al
Sent: Wednesday, January 23, 2013 1:00 PM
Subject: [Sentoa] Fw: Draining cummins qsb5.9 engine coolant





This may be more than you need to know. It applies to my 32-178 with a 5.9
old style engine, but I hope it applies to a large extent to your engine.
They are instructions I had written for my own use and modified by
correcting my goofs.


Draining or Changing the Main Engine Antifreeze 

Coolant Capacity (approximate)

- Engine 5½ gal

- Overflow tank ½ gal

- External hoses & heater units 1 gal


This can be a messy operation. With care, minimum spillage will occur.

Prepare with disposable gloves, newspaper, rags and absorbent pads. Have
ready 6 to 8 gallons of clean containers and a tall, large mouth funnel to
hold the antifreeze. If the antifreeze is to be replaced, it must meet the
ASTM 4985 / GM6038M spec. for low silicate ethylene glycol or propylene
glycol antifreeze. This is diluted 50/50 with distilled or deionized water
before replacing. See Cummins Service Bulletin 3666132-04.

Review these instructions before starting. Also, refer to procedure (008-
018), page 8-11, Trouble Shooting & Repair Manual.

Place a sign on the engine console: Do not operate the engine because it
has no coolant.

Drape rags over the generator and other parts of the engine, deck and bilge
below the starboard side of the expansion tank.

Have one large container ready with the long funnel in place.

Remove the cap on the expansion tank to prevent the antifreeze from being
siphoned from the plastic overflow tank.

Disconnect the upper end of the ¾ inch hose from the expansion tank and
hold the hose upright.IMMEDIATELY place the funnel to catch the flow from
the tank while continuing to hold the hose upright..

Once the tank is empty, the hose may be lowered to the funnel and the
antifreeze drained to the desired level in the engine, depending on the
work to be done.

When draining is complete, reattach the hose to the expansion tank. 


Refill the engine by pouring the saved antifreeze (or new 50% mixture)
SLOWLY through the expansion tank filler. Pour SLOWLY, otherwise, air
bubbles from the engine may cause the liquid to overflow!

When full, the level should be up to the bottom of the expansion tank
filler. Replace and TIGHTEN the filler cap.

OPEN THE SEACOCK . Start the engine and bring it up to operating
temperature. Check for leaks. CLOSE THE SEACOCK when done.

Check coolant level. If necessary, add mixture to the plastic overflow
tank, using a 2 foot vinyl hose and small funnel 

End of Engine Procedure

To replace ALL antifreeze including the external hoses and heaters.

Draining of coolant in the external circuit, if required, can be
accomplished after draining the engine as described in the preceding
section. Disconnect the return hose located forward of the oil filter,
catching the remaining coolant in the engine and from the hose as it is

Al McKenney
Nordic Star 32-178
Williamsburg VA
aem28 at verizon.net

----- Original Message ----- 

From: "Richard Paul" < <mailto:richard.062 at hotmail.com> richard.062 at hotmail.

To: < <mailto:sentoa at lists.sentoa.org> sentoa at lists.sentoa.org>

Sent: Monday, January 21, 2013 4:30 PM

Subject: [Sentoa] Draining cummins qsb5.9 engine coolant


I have a cummins QSB5.9 in my 2005 37. I would like to change the engine
antifreeze this spring. Anyone have any tips? Where is the best place to
extract the old coolant and how much does the system hold?

Thanks in advance for your help

Richard Paul
Summer Wind
NT 37/130

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