COOLANT CHANGE R31 D4-300

[KBHARDER]

Kevin Lamont

I’m getting ready to do a coolant change on a D4-300 and was also considering removing the feed line to the water heater to better purge the system. In your recent D3 reply on the same subject you mentioned a “small forward drain valve” on the D4. Is that drain valve mentioned here in addition to the two drain valves referenced in the maintenance manual located on the port side of the engine OR is it an additional drain valve located at the front of the engine?

Additionally, for anyone that has previously done a coolant change on the D4/6, any firsthand knowledge or advise would be much appreciated.

Since the two drain cocks are located in such a restricted access area, I see most of the coolant discharge ending up in the bilge. How has this been handled? Has anyone considered using an evacuation pump to easily siphon the coolant uphill to a remote collection bucket?

I am familiar with the specific coolant requirements and the procedure to ‘burp’ the system after refill.

Thanks in advance for your help.

Kim Harder
STARBIRD
2016 R31S

 

[S. Todd]

When draining coolant from our Volvo D-3 I inserted the suction hose on a West Marine oil extractor pump (manual vacuum pump) into the pet cock that drained the coolant. It was not a very tight fit so I still had to evacuate coolant from the bilge. The vacuum pump then allows me to poor the used coolant into gallon containers for proper disposal at our local recycling site. I am anxious to see how the process works for our newly purchased D-4.
Todd

 

[Gin]

Following.

 

[Kevin Lamont]

Kevin Lamont

I’m getting ready to do a coolant change on a D4-300 and was also considering removing the feed line to the water heater to better purge the system. In your recent D3 reply on the same subject you mentioned a “small forward drain valve” on the D4. Is that drain valve mentioned here in addition to the two drain valves referenced in the maintenance manual located on the port side of the engine OR is it an additional drain valve located at the front of the engine?

Additionally, for anyone that has previously done a coolant change on the D4/6, any firsthand knowledge or advise would be much appreciated.

Since the two drain cocks are located in such a restricted access area, I see most of the coolant discharge ending up in the bilge. How has this been handled? Has anyone considered using an evacuation pump to easily siphon the coolant uphill to a remote collection bucket?

I am familiar with the specific coolant requirements and the procedure to ‘burp’ the system after refill.

Thanks in advance for your help.

Kim Harder
STARBIRD
2016 R31S

Hello Kim,

The drain valve at the bottom of the engine on the port side should be marked in the manual. You can most definitely use a pump to suck out the coolant tank which would help remove most of the coolant. Than attaching to one of the drain valves on the engine to suck out the rest. You can also remove both heater hoses and use very low air psi to blow out the heater and hot water tank. I would say that the 31 has the most room in the engine bay to work on the motor and you should have small amount of coolant loss into the bilge. I would start by removing coolant from the tank than the heater/hot tank and finally the engine. When refilling you should be fine to fill the coolant tank till full, put the cap on and start the engine, run till warm (about 140), shut down and let cool so you can top off. You will need to run the engine under load to get the thermostat to open to final top off. Usually it will take a couple top offs to get full. Hope this helps.

Thanks,

 

[Gin]

Kevin, the spec for the D4 engine is that it holds 3.4 gallons of coolant. How much more is usually required for the lines that run to the hot water tank and the forward heater?