Coolent Change!

[EErmert]

O. K. , it's time to replace the antifreeze... have one of those "kits" that you plug into the hose, then use garden hose to "flush" system... need help with what hose, and how to completly drain water from eng, rad,... Anyone, and thanks in advance. (pictures would help!)



Eric - '03 3500 swb srw slt 4x4 6spd ho limited 373 qc 58k

 

[rbattelle]

Here's what the service manual says about flushing the engine:

STANDARD PROCEDURE - COOLING SYSTEM

CLEANING/REVERSE FLUSHING

CLEANING

Drain the cooling system and refill with water. Run

the engine with the radiator cap installed until the

upper radiator hose is hot. Stop the engine and drain

the water from system. If the water is dirty, fill the

system with water, run the engine and drain the system.

Repeat this procedure until the water drains

clean.

REVERSE FLUSHING

Reverse flushing of the cooling system is the forcing

of water through the cooling system. This is done

using air pressure in the opposite direction of normal

coolant flow. It is usually only necessary with very

dirty systems with evidence of partial plugging.

REVERSE FLUSHING RADIATOR

Disconnect the radiator hoses from the radiator

inlet and outlet. Attach a section of the radiator hose

to the radiator bottom outlet fitting and insert the

flushing gun. Connect a water supply hose and air

supply hose to the flushing gun.

CAUTION: Internal radiator pressure must not

exceed 138 kPa (20 psi) as damage to radiator may

result.

Allow the radiator to fill with water. When the

radiator is filled, apply air in short blasts. Allow the

radiator to refill between blasts. Continue this

reverse flushing until clean water flows out through

the rear of the radiator cooling tube passages.

REVERSE FLUSHING ENGINE

Drain the cooling system. Remove the thermostat

housing and thermostat. Install the thermostat housing.

Disconnect the radiator upper hose from the

radiator and attach the flushing gun to the hose. Disconnect

the radiator lower hose from the water pump

and attach a lead-away hose to the water pump inlet

fitting.

CAUTION: On vehicles equipped with a heater water

control valve, be sure the heater control valve is

closed (heat off). This will prevent coolant flow with

scale and other deposits from entering the heater

core.

Connect the water supply hose and air supply hose

to flushing gun. Allow the engine to fill with water.

When the engine is filled, apply air in short blasts,

allowing the system to fill between air blasts. Continue

until clean water flows through the lead away

hose.

Remove the lead away hose, flushing gun, water

supply hose and air supply hose. Remove the thermostat

housing and install the thermostat. Install the

thermostat housing with a replacement gasket. Refer

to Thermostat Replacement. Connect the radiator

hoses. Refill the cooling system with the correct antifreeze/

water mixture. Refer to Refilling the Cooling

System.

Note: we don't have a heater water control valve.



Ryan

 

[EErmert]

Ryan: Thank you for the reply! I do have the service manual; however, it seems that draining ALL of the old coolant from eng. , rad. , is best way to go...

Thanks again, Eric

 

[rbattelle]

True, but the best (only?) way to do that is with compressed air. If you've got an air source, go for it! I would.

Ryan

 

[Old Man]

This is what I copied about 5/6 yrs ago that was posted by Steve St. L.

I have used it since. Let me quote:



Here's how I did mine and I got approximately 5. 5 gallons into the system. First I opened the petcock on the radiator (turn it, then pull on it a lit, turn, pull, turn, pull - until it starts draining), that will drain the fluid out of the overflow bottle, once the overflow bottle is empty, then take the radiator cap off. Now pull the hose connector off the top of the engine and remove the thermostat. Once it stops draining, pour distilled water into both the inside and outside holes in the thermostate hole until you see clear water flowing out of the radiator. Now pour in straight 100% coolant into those same two holes until you see coolant running out the radiator. Close the radiator petcock. Some of the water and some of the 100% coolant will be trapped in the system - should be around 50/50. Now pour in either pre-mix or mix 50% coolant with 50% distilled water in through the thermostate hole until the system is as full as you can get it. Then put the new thermostat in and top radiator hose connector. Finish filling the radiator with the mix, close the radiator cap and then fill the overflow bottle. Run the truck until it's warmed up (so the thermostat opens) and then check the overflow bottle again.

Using this method, I was able to get in approximately 5. 5 gallons and I didn't have any problems with trapped air because I was backfilling the system from the engine to the radiator. You want to use distilled water only so you don't get mineral depposits in your coolant system.

 

[Old Man]

One more thingy:



Mark the overflow bottle for reference to see if you need to add any more coolant. I use a plastic hose at the petcock nipple, secured with a wire tie, and some plastic milk jugs (gal) to catch the old coolant for recycle. The plastic hose was long enough that I could "shove" it back inside the frame for future use. The two bolts at the thermostat/hose does not take much torque. Maybe someone will chime in with the correct torque.

 

[DBentley]

I was always told to remove only the lower rad. hose at at rad. with motor warm not hot and let it drain and the siphon action would pull about as much of the old coolant out as posible.