Cooling system bleeder Problem
Thread Starter
TECH Enthusiast
Joined: Feb 2012
Posts: 631
Likes: 0
From: Orlando
Cooling system bleeder Problem Just doing some preventative maintenance and decided to change the Antifreeze/coolant so make sure the water pump lasts a little longer. Let the coolant leak out the bottom of the radiator (slow process) (only had 1 gallon) so I took out 3/4’s of old coolant and had a new gallon I bought. closed back up the drain plug. Then filled the radiator with only a few cups of coolant before it stopped taking any. Tried turning the motor on and opening up the bleeders, and that is when the coolant rose up from the top of the cap and was spilling, and was overflowing. Tried squeezing the hoses and nothing. I ended up wasting about 1/2 gallon of coolant. No coolant will bleed out of the top bleeder next to the alternator. Coolant rose every time I opened up the top bleeder. Now what I missing???
Obviously there is air but where? I cant run the car too long then the obvious happens..
Obviously there is air but where? I cant run the car too long then the obvious happens..
Last edited by 93Euphoria; Aug 7, 2013 at 10:33 PM.
The LT1s can be a bit of a PITA to "burp". You need to fill the radiator, but not to the top, turn on the heater, start the engine and let it come up to temp. As the air escapes from the radiator, SLOWLY top off the coolant, but while you're doing this, also crack the 2 air bleeds in the hoses every 30 seconds or so, until the coolant level stabilizes in the radiator.
Here is the way I have bled without any issues:
Open both bleeders
fill radiator with coolant/liquid of choice
you will hear hissing, completely normal
as you're filling coolant will start bubbling out of the t-stat bleeder, shut it
fill radiator until it's about 2" from the fill neck
close top/heater hose bleeder
start engine and keep radiator cap off
coolant will start to spit out of the coolant return line inside the radiator
once a steady stream runs out of return line then the engine is pretty much bled of air. if coolant level drops suddenly from the opening of the t-stat make sure to fill coolant until level is pprox 2" from the top
if coolant rises to the point of overflowing from radiator, put cap on
let system pressurize
check temp gauge
open the t-stat bleeder, if steady flow of coolant, shut it
open heater hose bleeder, if there is air, let it bleed out. if system depressurizes while bleeder is open, shut it again and let coolant pressurize
check temp gauge
repeat process of opening heater hose bleeder until coolant stream runs steadily out.
It's possible you will not get all air out of system. Check coolant level for the first few days of driving.
You never want to open the bleeders if the radiator cap is off. That will only introduce more air into the system. Once the radiator is full only open the bleeders when the system is pressurized.
Open both bleeders
fill radiator with coolant/liquid of choice
you will hear hissing, completely normal
as you're filling coolant will start bubbling out of the t-stat bleeder, shut it
fill radiator until it's about 2" from the fill neck
close top/heater hose bleeder
start engine and keep radiator cap off
coolant will start to spit out of the coolant return line inside the radiator
once a steady stream runs out of return line then the engine is pretty much bled of air. if coolant level drops suddenly from the opening of the t-stat make sure to fill coolant until level is pprox 2" from the top
if coolant rises to the point of overflowing from radiator, put cap on
let system pressurize
check temp gauge
open the t-stat bleeder, if steady flow of coolant, shut it
open heater hose bleeder, if there is air, let it bleed out. if system depressurizes while bleeder is open, shut it again and let coolant pressurize
check temp gauge
repeat process of opening heater hose bleeder until coolant stream runs steadily out.
It's possible you will not get all air out of system. Check coolant level for the first few days of driving.
You never want to open the bleeders if the radiator cap is off. That will only introduce more air into the system. Once the radiator is full only open the bleeders when the system is pressurized.
Thread Starter
TECH Enthusiast
Joined: Feb 2012
Posts: 631
Likes: 0
From: Orlando
Ok guys she is running ok now. Bleeding is ok. 1 thing isnt right. Now I know why the car has been running hotter lately. The damn fans wont come on. The primary ones; The ones that run 24/7. Originally before the coolant mini flush the car was getting unusually hotter in traffic 210-220 didnt cool off until I was cruising for a few minutes or gave her some WOT. I changed some coolant, now I think I know why it was running hotter than usual. The fans! Miss when it would never get above the 2nd mark. Been reading on shoebox and it tells me primary comes on at 210, but before the low speed fans would come on at a cold startup or way before the car hits 210. Any ideas why that could be? Could it be water pump temp sensor? PCM was never tuned btw.
Lol I guess the a/c Issue has something to do with the fans not coming on when there supposed to.
Can someone elaborate on that a little more?
Lol I guess the a/c Issue has something to do with the fans not coming on when there supposed to.
Can someone elaborate on that a little more?
Last edited by 93Euphoria; Aug 8, 2013 at 12:54 PM.
TECH Veteran
Joined: Dec 2008
Posts: 4,145
Likes: 61
From: Little Rock, AR
Ok guys she is running ok now. Bleeding is ok. 1 thing isnt right. Now I know why the car has been running hotter lately. The damn fans wont come on. The primary ones; The ones that run 24/7. Originally before the coolant mini flush the car was getting unusually hotter in traffic 210-220 didnt cool off until I was cruising for a few minutes or gave her some WOT. I changed some coolant, now I think I know why it was running hotter than usual. The fans! Miss when it would never get above the 2nd mark. Been reading on shoebox and it tells me primary comes on at 210, but before the low speed fans would come on at a cold startup or way before the car hits 210. Any ideas why that could be? Could it be water pump temp sensor? PCM was never tuned btw.
Lol I guess the a/c Issue has something to do with the fans not coming on when there supposed to.
Can someone elaborate on that a little more?
Lol I guess the a/c Issue has something to do with the fans not coming on when there supposed to.
Can someone elaborate on that a little more?
Thread Starter
TECH Enthusiast
Joined: Feb 2012
Posts: 631
Likes: 0
From: Orlando
The reasoning, causes, and cure for it. Thanks Shbox.
Trending Topics
TECH Veteran
Joined: Dec 2008
Posts: 4,145
Likes: 61
From: Little Rock, AR
If a/c operation is inhibited by the PCM, the fans don't need to come on when the a/c is turned on (and not working). The reason the fans come on with the a/c is to allow the a/c to work more efficiently-not to keep the engine cool. None of that has anything to do with normal fan operation by temperature.
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
