NO! The air bubble problem is usually cause by opening the radiator cap and
letting air in... only supposed to check/add coolant at the over flow bottle in
most new trucks..
Ok.. no idea on a chevy, but on the dakota 4.7 and the cryco vans there is a
screw and fitting on the upper radiator hose near the filler cap.. it says "air
Warm up engine, open the screw a bit... when the air stops and the discharge is
all coolant, close it..
problem occurs (as I understand it) because unlike the older, higher profile
engine designs, the radiator cap is no longer the highest point in the cooling
system, so opening the cap lets air IN, not out..
I found this out the hard way back in 01, the 1st time that I checked coolant in
my Dakota... and had over heating problems for weeks until the folks in the
dodge truck group told me about the air bleed.. (which I thought was nuts, but
Please remove splinters before emailing
Darrell, On a chevy its ok to leave the cap off till the truck gets warm and
you can see water flowing around the inside of the radiator. It wont cause
air to be introduced into the system. Although, The other guy is right in a
way. If you fill the radiator full, and then fill your expansion tank half
full, then any air in the system will be discharged when the system warms
up, and then any fluid that the radiator needs to make up that loss will be
suctioned back out of the expansion tank.
If your radiator is getting low, and your expansion tank is not, then you
have a problem. If that is happening, take your truck to a mechanic and have
them pressure test the system to see if it holds 15Lbs of pressure, and then
have them check the radiator cap to see if it holds 15lbs of pressure. They
have a special tool that allows them to do this.
Another thing that might be happening, if you take the cap off your radiator
and it is under pressure, then you probably have a bad gasket somewhere
either its the head gasket or the intake. You could also possibly have a
cracked block, but usually a gasket will go first.
yes, turn on heater, let truck run with cap off radiator,
that's what I do.
When truck is cold, open radiator cap, start engine and let run for a
while until the thermostat opens up.(if you give it to much gas (RPM)
you are going to overflow the radiator. Just let it run and once the
thermostat opens check the coolant level and add if required. Let run
a little longer and replace radiator cap and your done. I've done this
any number of times.
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