does any body know how you are supposed to bleed the air out of the cooling system of my 5.7 liter 1993 cheyy silverado 4x4.Do I just open cap with the heater on or is there more? also it has a slight miss is this a comman thing that can be fixed in the distriutor?Has new plugs wires and rotor cap and distributor cap Thank you for any info Darrell
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 bleed"... 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 it worked)
mac
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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.
Pk
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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