It’s been a while since I did this.
I remember flushing the system about three times before I got clear water through the system.
I know that Dex requires a 50/50 mixture with distilled water.
But what volume of water remains in the block?
In other words how much extra Dex has to be added to balance the mixture?
Thanks,Tom.

 

Here's something I got on a previous post.

Originally Posted by 01QuickSilver
I used 6 1/2 qts. of Dex-Cool (manual says system holds 13 qts.) & my garden hose.

The difference between FLUSHING and REFILLING is:
Flushing uses water under pressure to rinse all of the old coolant and corrosion, sediment, etc. out. Refilling is
just that - refilling.
Also, if all you do is drain the radiator & refill it you will be leaving the block and heater core full of old coolant!!

I'm sure there are many who could provide a more technical sounding description, but here's how I FLUSHED
mine BOTH WAYS:

1.Set heater temp to full hot (90)
2.Open radiator drain
3.Remove both radiator hoses @ water pump
4.Remove both heater hoses @ water pump
5.Remove water pump inlet housing (thermostat is part of the inlet).
6.Flush water through both heater hoses - this does the core both ways.
7.Plug the heater hose fittings on the water pump (I stuffed shop towels in) and flush water through the water
pump where each
rad. hose goes - this does the block both ways
8.Flush the resevoir tank
9.Flush water through top & bottom rad. hoses - this does the radiator both ways
10.Close radiator drain, connect all hoses. Leave the inlet hsg. off the pump for now
11.Pour Dex-Cool in resevoir very slowly until it gets up to the bottom of the hole where the inlet/therm hsg goes
(much like filling a manual trans) - this eliminates much trapped air
12.Install inlet/therm hsg, lower rad. hose & finish filling - total of 6 1/2 qts. Dex-Cool first, then finish with water
13.Run engine to operating temp with cap off resevoir while checking for leaks, shut off engine and let it cool down
14.After engine is cool add water as needed & install cap
15.Check level & top off after the next few times you drive until it stabilizes
Smile as you think about how much $$$ you saved



Another added bit of info

Caution
With a pressurized cooling system, the coolant temperature in the radiator can be considerably higher than the
boiling point of the solution at atmospheric pressure. Removal of the surge tank cap, while the cooling system
is hot and under high pressure, causes the solution to boil instantaneously with explosive force. This will cause
the solution to spew out over the engine, the fenders, and the person removing the cap. Serious bodily injury
may result.

Important
If the procedure below is not followed a low or high coolant level condition and/or vehicle damage could result.

1) Park the vehicle on a level surface.
2) Remove the surge tank cap:
3)Raise and suitably support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.
4) Place a drain pan under the drain fowl.
5) Open the radiator drain fowl.
6) Allow the cooling system to drain completely.
7) Inspect the engine coolant for the following:
Discolored -- follow the flush procedure below.
Normal in appearance -- continue with the next step.

Notice
When adding coolant, use DEX-COOL® coolant. If silicated coolant is added to the system, premature
engine, heater core or radiator corrosion may result. In addition, the engine coolant will require change
sooner-at 50 000 km (30,000 mi) or 24 months.

Notice
Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that
application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant
are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or
fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may
damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to
avoid damage to parts and systems.

8) Close the radiator drain fowl. Tighten.
Tighten the radiator drain fowl to 2 N·m (18 lb in).
9) Fill the cooling system through the surge tank.
10) Fill the cooling system with a 50/50 mixture of DEX-COOL® coolant and deionized water.
11) Start the engine.
12) Allow the engine to idle for 1 minute.
13) Install surge tank cap.
14) Cycle the engine RPMs from idle to 3000 in 30 second intervals until the coolant temperature
reaches 99°C (210°F).
15)Shut off the engine.
16) Remove the surge tank cap.
17) Start the engine.
18) Allow the engine to Idle for 1 minute. Fill the surge tank to 12.7 mm (0.5 in) above the COLD FULL mark on
the surge tank.
19) Install the surge tank cap.
20) Cycle the engine RPMs from idle to 3000 in 30 second intervals until the coolant reaches 99°C (210°F).
21) Shut off the engine.
22) Remove the surge tank cap.
23) Top off the coolant as necessary, 12.7 mm (0.5 in) above FULL COLD mark on the surge tank.
24) Rinse away any excess coolant from the engine and the engine compartment.
25) Inspect the concentration of the engine coolant.
26) Install the surge tank cap.