Coolant fill Question??
Thread Starter
Team Owner
Joined: Feb 2006
Posts: 23,131
Likes: 117
From: San Antonio Texas
Coolant fill Question??
OK, I can get the water out by the drain plug in the radiator, knock sensors & pulling hoses etc. But how do you get the coolant back in after your repair work is done? There are 2 holes in the expansion tank just below the fill cap. One goes to the overflow/recovery bottle and the other goes to a small line to the top of the radiator. The hole for that line is TINY! It looks like it would take all day to fill the engine and radiator through that pencil sized hole. I know about the air bleed hole by the thermostat, but is that the only way to fill a C4? I was thinking of pouring a bunch of coolant in the open top hose before I reconnected it to the thermostat housing, and then try to fill it the rest of the way at the tank. Will that work?
Melting Slicks
Joined: Apr 2002
Posts: 2,118
Likes: 0
From: St. Charles, MO Route 66 Corvette Club
Not trying to be a smart **** ....... but you should pour new coolant into the radiator thru the hole that is left when you remove the pressurized radiator cap. Add coolant until the radiator is full ......assuming you have the burp holes drilled into the t'stat. Fill the reservoir tank to the cold level and start 'er up! Make sure the t'stat opens and the fans work as expected.
The small hole is for expansion and contraction due to heating and cooling of the engine coolant. The overflow goes into the reservoir to the HOT level. As the engine cools, it draws fluid back into the radiator.
If this does not answer your question, let us know.
The small hole is for expansion and contraction due to heating and cooling of the engine coolant. The overflow goes into the reservoir to the HOT level. As the engine cools, it draws fluid back into the radiator.
If this does not answer your question, let us know.
Race Director
Joined: Oct 2005
Posts: 11,770
Likes: 175
From: Rolla Missouri
2021 C4 of the Year - Unmodified Finalist
St. Jude Donor '10 thru '25
I think most of you people are forgetting, the LT1/LT4 does not have a normal radiator cap (attached to the radiator) like the L98 and earlier.
But not to worry. The expansion tank has the radiator cap as noted, and you see that tiny little line going to the radiator. BUT, look at the bottom of that tank and you will see two hoses (approx. 3/4 inch) that go to the water pump. As you fill the tank, coolant will flow through those lines.
But not to worry. The expansion tank has the radiator cap as noted, and you see that tiny little line going to the radiator. BUT, look at the bottom of that tank and you will see two hoses (approx. 3/4 inch) that go to the water pump. As you fill the tank, coolant will flow through those lines.
Team Owner
Joined: Dec 1999
Posts: 34,873
Likes: 487
From: Lacey WA RVN 68-69
NCM Sinkhole Donor
Ethlyene glycol (green coolant) is the proper coolant to use. Mix it 50/50 with distilled water. I'm not a fan of "universal" coolants, it's just too easy to get the proper type of coolant for the car.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)
Joe Kucinski
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
10 Revolutionary 'Corvette Firsts' Most People Don't Know
Joe Kucinski
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2
Michael S. Palmer
2027 Corvette vs The World: Every C8 vs Its Closest Competitor
Joe Kucinski
Le Mans Master
Joined: Jul 2002
Posts: 5,818
Likes: 2
From: Alive and well in Burlington NC
I
But not to worry. The expansion tank has the radiator cap as noted, and you see that tiny little line going to the radiator. BUT, look at the bottom of that tank and you will see two hoses (approx. 3/4 inch) that go to the water pump. As you fill the tank, coolant will flow through those lines.
But not to worry. The expansion tank has the radiator cap as noted, and you see that tiny little line going to the radiator. BUT, look at the bottom of that tank and you will see two hoses (approx. 3/4 inch) that go to the water pump. As you fill the tank, coolant will flow through those lines.
Fill it just like you would any automotive cooling system. Just keep the coolant bottle handy. The surge tank can empty pretty quick.
Drifting
Joined: Sep 2005
Posts: 1,867
Likes: 3
From: Pasadena Maryland
The LT-1 also need to be BURPED, mine has a fitting on the Water Pump (housing?) It's on one of the large hose fittings. A small fitting that you can open to allow air to escape from the system.
Burning Brakes
Joined: Feb 2002
Posts: 804
Likes: 5
From: Fresno CA
It depends on how often you will be doing it but I bought this vacuum cooling system filler from Snap-On and it works great! No need to burp the system or worry about trapped air in the system.
http://buy1.snapon.com/catalog/item....store&tool=all
http://buy1.snapon.com/catalog/item....store&tool=all
