Suggestions for draining coolant

[Max Simmons]

I'm planning on cleaning the manicoolers and pulling and evaluating exhaust elbow this spring (Perk 6.534's)
One of the biggest PIA's on something like this for me is to drain the coolant. Usually the drain plug is in a tight spot and hard to control the fluid after it's removed. I just ran into this while replacing the turbos on my friends Volvos. Also, it always seems like there is a helluva lot more coolant coming out than I ever put in!
Just wondering if anybody has words of wisdom, or a unique method of draining the coolant without making a big mess.

 

[High Wire]

There are two drain plugs. One above the starter and the other on opposite side about the same location. It’s just NPT plugs. I forget what size. Coolant capacity is about 6 gallons. As long as the coolant is not hot, you can stop the flow with your finger. If loose coolant is a problem you can make a simple drain rig, hose barb adapter, and some tubing.

 

[porman]

I gave up trying to collect the coolant when draining my two Yanmars. It was almost impossible to get a drain pan under the lowest petcock. Now I just let them drain into the bilge under each engine and suck it out at a convenient spot. Then I run fresh water from a hose to clean any residue from the bilge. I don't have to worry about it getting pumped overboard because it has to get about 6 inches deep before it will flow over the stringers and get to the bilge pump in the center of the boat.

 

[DennisB1]

I have been using a hand vacuum pump used often for changing oil. Holds about 2 gallons. I have been able to get about 4 gallons (about half) out of a cat 3208. A small tube is inserted into the filler cap port. Then transfer using the pump to your storage contain and repeat as required. Easier than draining all of the fluid.

 

[rgano]

I put a wet/dry vacuum hose up to the drains and let her rip. Very little in the bilge.

 

[Bacchus]

There are two drain plugs. One above the starter and the other on opposite side about the same location. It’s just NPT plugs. I forget what size. Coolant capacity is about 6 gallons. As long as the coolant is not hot, you can stop the flow with your finger. If loose coolant is a problem you can make a simple drain rig, hose barb adapter, and some tubing.

When drained my Yan 370 coolant above is what I found 1 drain near starter port side and another one on stdb. I cut a plastic gal jug to fit under the drains and let them drain into the jug. I got a batty transfer pump from Harbor Frt and used it to transfer from jug to empty containers and was successful caprturing almost 100%.
I flushed once with distilled water and drained again. Then refilled with premixed coolant and replaced the Tstat.
Mine were peacock type fittings that a socket fit and helped open them w/o too much trouble.

 

[Comodave]

Interesting thread, I need to change the coolant in my 6CTAs this spring. Thanks for the ideas, following.

 

[socalrider]

My Lehmans have a 1/4 npt drain port on the port side. It's been a mess every time, so trying something new:

I just ordered a couple of these brass drain valves. Gonna get some flex tubing and drain it into a 5gal bucket in the bilge (I have a pretty deep bilge). Will let you know how it works.

https://www.mcmaster.com/4794K21/

 

[syjos]

I installed a T in the coolant line running to the hot water heater fitted with a valve and hose bib.

I remove the expansion tank cap and connect a pump to the hose bib on the T and suck the coolant out through a hose into a container.

When drained, reverse pump, stick hose into fresh coolant. If you don't know capacity, keep an eye on the expansion tank so the pump can be turned off before overfilling.

No need to bleed air since coolant was pushed in from the bottom, expelling air as it rises. During filling, the hose on either side of the T could be pinched alternately to rid air pockets and move coolant to either side of the thermostat. This is where a 1/8" hole in the thermostat is helpful.

 

[High Wire]

And don’t forget to loosen the cap to let air in.

 

[Bacchus]

If anyone with a Yanmar is following here is a coolant change thread with pics.
https://www.trawlerforum.com/forums/showthread.php?t=14286

 

[Flatswing]

My Lehmans have a 1/4 npt drain port on the port side. It's been a mess every time, so trying something new:

I just ordered a couple of these brass drain valves. Gonna get some flex tubing and drain it into a 5gal bucket in the bilge (I have a pretty deep bilge). Will let you know how it works.

https://www.mcmaster.com/4794K21/

I replaced my JD 6068 1/4” npt petcocks with brass hot water 1/4 turn valves with a hose barb from big box store. Sure the brass will get brittle with time but cheap exchange. Works like a charm which is critical ‘cus the 6068’s need to drop several gals of coolant for any work on the serpentine belt or heat exchanger!