Coolant "flush"

big_dawg74 · May 1, 2011

Ok, so I'm going to dump the coolant soon in my truck. Is this the jist of it?:

1) Pull lower hose & make big mess

2) Attach lower hose.

3) Fill surge tank with garden hose water. Run truck w/ heater on for 10-15 mins.

4) Stop engine and repeat steps one and two.

5) Fill surge tank w/ 2 gals on DexCool and 2 gals on distilled H2O.

6) Run truck for awhile and adjust coolant level as necessary.

??

8.1HD/ALLISON · May 1, 2011

Should work just fine. Also while you have the coolant system open, backflush the heater core. Follow the 2 hoses from the firewall and remove them from the engine. Flush back and forth till it runs clear. 4.3's are bad about clogging heater cores up.

tyhuck · May 1, 2011

I bought the little backflush kit from walmart. I think its made by Prestone. I used it on my S10 4.3 and it worked great.

big_dawg74 · May 1, 2011

Should work just fine. Also while you have the coolant system open, backflush the heater core.

Matt...won't running the truck w/ the heater on high circulate the water through the heater core?

txab · May 1, 2011

Should work just fine. Also while you have the coolant system open, backflush the heater core.

Matt...won't running the truck w/ the heater on high circulate the water through the heater core?

Water runs through the core at all times. Matt is suggesting BACKFLUSHING the core. Running the water through the core in the opposite direction...... Disconnect the lines and flush as he suggests, you won't regret it. BTW, the high heater setting changes nothing on the amount of water flow through your core......

big_dawg74 · May 2, 2011

Should work just fine. Also while you have the coolant system open, backflush the heater core.

Matt...won't running the truck w/ the heater on high circulate the water through the heater core?

Water runs through the core at all times. Matt is suggesting BACKFLUSHING the core. Running the water through the core in the opposite direction...... Disconnect the lines and flush as he suggests, you won't regret it. BTW, the high heater setting changes nothing on the amount of water flow through your core......

Ok, now that I went back and re-read that, it makes sense. Thank you!