Need to drain my...
Thread Starter
Burning Brakes
Joined: Jan 2006
Posts: 900
Likes: 38
From: Waunakee Wisconsin
St. Jude Donor '20
Need to drain my...
I want to drain the coolant in my 1999 coupe. If I just drain the radiator, what % of the total fluid will I change out? I've heard power flushes are not a good idea. Any thoughts?
Racer
Joined: Oct 2006
Posts: 445
Likes: 0
From: State of Perplexity California
Geez, with that title my mind was racing. He wants to drain his what? Bank account? Swimming pool? Lizard?
Ah, just a radiator. I see.
Well, why just do that? Let's say you get out half (approximate, don't have my manuals here.) Why stop there? You already have to get a little messy and dispose of the waste. Why not just fill it back up with water, run until the thermostat opens, drain again, repeat till clear. Then put in the required amount of coolant, and top off with water. (Distilled, tap, Evian, whatever you prefer.) And you're done!
Ah, just a radiator. I see.
Well, why just do that? Let's say you get out half (approximate, don't have my manuals here.) Why stop there? You already have to get a little messy and dispose of the waste. Why not just fill it back up with water, run until the thermostat opens, drain again, repeat till clear. Then put in the required amount of coolant, and top off with water. (Distilled, tap, Evian, whatever you prefer.) And you're done!
Instructor
Joined: Aug 2004
Posts: 132
Likes: 1
I sure am not smart enough to know what % will be left in the engine but I know it is not rocket science to flush and fill antifreeze.
I would drain the radiator. Fill with water and run the car with the heater on high until the thermostat opens. Do this several times. If you pull the thermostat (two bolts) you can run water from the garden hose though the engine too. Pulling the hoses from the water pump and flushing those helps too.
Just takes time, especially if you are waiting for the thermostat to open and a lot of water but it is not difficult and I highly recommend it be done every couple of years. Very little cost to prevent scale, rust and corrosion.
I would drain the radiator. Fill with water and run the car with the heater on high until the thermostat opens. Do this several times. If you pull the thermostat (two bolts) you can run water from the garden hose though the engine too. Pulling the hoses from the water pump and flushing those helps too.
Just takes time, especially if you are waiting for the thermostat to open and a lot of water but it is not difficult and I highly recommend it be done every couple of years. Very little cost to prevent scale, rust and corrosion.
Le Mans Master
Joined: Feb 2002
Posts: 6,937
Likes: 21
From: Waldorf MD
I drained out all but 2 quarts of mine. Keep car level after opening drain plug. Shop manual says no need to flush if it is clean. Mine was, I did not flush.
Do use distilled water. Fill at least 3 times, reving it up to 3,000 rpms and waiting until it reaches 190 degrees. This gets air out.
With dexcool, once every 5 years or 150,000 miles is okay (Really).
Do use distilled water. Fill at least 3 times, reving it up to 3,000 rpms and waiting until it reaches 190 degrees. This gets air out.
With dexcool, once every 5 years or 150,000 miles is okay (Really).
Thread Starter
Burning Brakes
Joined: Jan 2006
Posts: 900
Likes: 38
From: Waunakee Wisconsin
St. Jude Donor '20
Geez, with that title my mind was racing. He wants to drain his what? Bank account? Swimming pool? Lizard?
Ah, just a radiator. I see.
Well, why just do that? Let's say you get out half (approximate, don't have my manuals here.) Why stop there? You already have to get a little messy and dispose of the waste. Why not just fill it back up with water, run until the thermostat opens, drain again, repeat till clear. Then put in the required amount of coolant, and top off with water. (Distilled, tap, Evian, whatever you prefer.) And you're done!
Ah, just a radiator. I see.
Well, why just do that? Let's say you get out half (approximate, don't have my manuals here.) Why stop there? You already have to get a little messy and dispose of the waste. Why not just fill it back up with water, run until the thermostat opens, drain again, repeat till clear. Then put in the required amount of coolant, and top off with water. (Distilled, tap, Evian, whatever you prefer.) And you're done!
I think I'll run the engine as you described to remove even more of the old product. I've got a '99 with 30K on the clock. Even though it looks O.K., it's time.
Le Mans Master
Joined: Sep 2004
Posts: 6,019
Likes: 568
From: Conroe Texas
are there drain ***** on the lower walls of the block? on the sbc's we would pull the plugs in the lower block and drain both sides of the block. or we would pull one of the heater hoses and force water through there. but i see that both heater hoses on the ls motor are in the t-stat housing. is there a divider inside the housing to direct the water flow through the block?
Le Mans Master
Joined: Sep 2003
Posts: 8,847
Likes: 795
From: Longview Texas
I think just draining the radiator gets you about 2 gallons, which leaves 1 gallon in the block. The total capacity is about 12 quarts.
If you flush until you have just water left in the block, you would need to add 6 quarts to the radiator, then finish with distilled water for a 50/50 mixture.
If you flush until you have just water left in the block, you would need to add 6 quarts to the radiator, then finish with distilled water for a 50/50 mixture.
Thread Starter
Burning Brakes
Joined: Jan 2006
Posts: 900
Likes: 38
From: Waunakee Wisconsin
St. Jude Donor '20
I think just draining the radiator gets you about 2 gallons, which leaves 1 gallon in the block. The total capacity is about 12 quarts.
If you flush until you have just water left in the block, you would need to add 6 quarts to the radiator, then finish with distilled water for a 50/50 mixture.
If you flush until you have just water left in the block, you would need to add 6 quarts to the radiator, then finish with distilled water for a 50/50 mixture.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Every 2027 Corvette Engine Explained
Joe Kucinski
Designer Imagines A Corvette That Looks More Like a Corvette Than the Corvette
Verdad Gallardo
10 Ugly Corvettes That We Still Kinda Love
Joe Kucinski
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
