HELP! Radiator Plug

[austinlothar]

I have a '99 Tahoe and I am trying to drain and fill the radiator. For some reason I can't find the dang plug. Anything special I need to do to get to it or am I just blind? Please let me know. A link to a diagram would be awesome.

THANKS!

[Shortbus]

The drain plug is goofey on these, here is an illustration and procedure.
You need a 1/4 inch Allen head tool. To open the drain cock.

1. Place a drain pan under the radiator drain cock.
2. Place the end of the tube in the drain pan.
3. After the engine cools down, remove the radiator cap.
4. Using a 1/4 in drive, completely open the radiator drain cock.
5. Allow the coolant to drain from the system until the flow stops.
6. Place a drain pan under the block drain hole plug.
7. Remove the drain hole plug from the engine block.
8. Allow the coolant to drain from the block until the flow stops. There may be more drainage from the radiator at this time.
9. Install the block drain hole plug.
10. Close the radiator drain cock.

Filling Procedure

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.


Ensure that the radiator drain cock is closed.



Ensure that the block drain hole plug is tight.
Add the DEX-COOL® to the radiator, then add clean drinkable water to the cooling system. If you use the old coolant, ensure that the solution is clean and clear, and that the solution is a 50/50 mixture of glycol and water.
Place a large top funnel in the radiator filler neck or surge tank.
Slowly pour in the coolant. Because the thermostat is closed, filling the cooling system may be slow.
After you fill the cooling system to 13 mm (0.5 in) below the radiator filler neck (Gas Engines) or to the full mark on the surge tank (Diesel Engines), start the engine and let the cooling system warm up. When the thermostat opens, the coolant level may drop. If the level drops, add coolant as needed.
Install the radiator or surge tank cap.
Inspect the coolant level in the coolant recovery reservoir (Gas Engines) or the surge tank (Diesel Engines). Add coolant as needed.

[Shortbus]

PS
The drain plug is on the drivers side of the radiator at the bottom corner facing the engine.

[austinlothar]

Thanks! That helps a lot.

[Shortbus]

No problem.

[Mr Chips]

The radiator drain plug on the the 96 Tahoe must be burried somewhere. Can't find it.

When filling the radiator should you run the heater?

Any suggestions
Thanks

[k5sbu]

Good information on the radiator drain plug location. I discovered the drain plug on my '99 Tahoe is soft white plastic. When I put the 1/4 inch allen wrench into it I discovered the hole was eaten out round by some amateur before me! The top end of the plug has a one way slot in it that allows the plug to be installed but not removed except as you indicate, with the allen tool.

Incidentally, I recommend the Preston Flush Kit as it does push fresh water through the heater core and engine block rather well and exhaust the flush water out the top of the radiator. That is better than a straight gravity drain.

Question 1:
Any ideas on removing the damaged plug? On my unit there is very little working space around the drain cock so the solution has to be physically small. Perhaps an Easy-Out tool?

Question 2:
You mentioned an engine block coolant drain plug, but where is it located?

Thanks,
RIK

[texmex]

Originally Posted by Mr Chips

The radiator drain plug on the the 96 Tahoe must be burried somewhere. Can't find it.

When filling the radiator should you run the heater?

Any suggestions
Thanks

the drain plug for a 97 tahoe is on the very bottom left of the radiator and a pain to get to. it can be opened without any tools if you can get your hands on it. i found with my 96 Z71 that you can remove the black storage compartment and the purge canister to get your hands on the drain plug. then just follow the directions that Shortbus posted above.
keep up with flushing the radiator. i neglected mine and ran into alot of overheating problems due to corrosion and rust built up in the radiator

[texmex]

it should say on the back of the coolant bottle how to fill the radiator. my guess is you do run the heater when filling

[Mikado14]

Coolant flows through the core continually. No need to run the heater.

[Shortbus]

Actually if its on a Tahoe there is still a water control valve on them that keeps coolant from flowing through the heater core continually.

[Mikado14]

I learned something, thanks!