Coolant change out
Thread Starter
Melting Slicks
Joined: May 2000
Posts: 2,498
Likes: 4
From: Brentwood TN
Coolant change out
Got all ambitious this morning, going to change coolant, can't get the petcock to open. It turns about 1/8 of a turn CCW but not 1/4 turn as I expected but I don't want to put a lot of muscle behind it and break it off. I think someone already did that since the petcock has a tab on it instead of the 1/4" drive.
So - should I just give it a little harder turn to get a full quarter turn or is 1/8 enough and there's enough crud in my radiator that the petcock is plugged? If it's plugged, what is involved in pulling the petcock to drain the radiator?
Charlie
So - should I just give it a little harder turn to get a full quarter turn or is 1/8 enough and there's enough crud in my radiator that the petcock is plugged? If it's plugged, what is involved in pulling the petcock to drain the radiator?
Charlie
Thread Starter
Melting Slicks
Joined: May 2000
Posts: 2,498
Likes: 4
From: Brentwood TN
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Got all ambitious this morning, going to change coolant, can't get the petcock to open. It turns about 1/8 of a turn CCW but not 1/4 turn as I expected but I don't want to put a lot of muscle behind it and break it off. I think someone already did that since the petcock has a tab on it instead of the 1/4" drive.
So - should I just give it a little harder turn to get a full quarter turn or is 1/8 enough and there's enough crud in my radiator that the petcock is plugged? If it's plugged, what is involved in pulling the petcock to drain the radiator?
Charlie
So - should I just give it a little harder turn to get a full quarter turn or is 1/8 enough and there's enough crud in my radiator that the petcock is plugged? If it's plugged, what is involved in pulling the petcock to drain the radiator?
Charlie
Last edited by American Hydrocarbon; Jan 12, 2008 at 04:01 PM. Reason: typo
Burning Brakes
Joined: Sep 2007
Posts: 1,048
Likes: 300
From: FL
Don't force the petcock or it will break. Ask me how i know. If it only turns an 8th of a turn, try pulling it straight out a little at that point. It should drain then. If there is something keeping it from turning just remove the whole petcock then you will be able to see what's going on with it but I think the 8th turn is all you're going to get. What you break off by forcing it is the pin that guides it thru the opening/closing process via a small groove/ramp. If you can get close enough to the petcock you can see this groove/ramp.
Thread Starter
Melting Slicks
Joined: May 2000
Posts: 2,498
Likes: 4
From: Brentwood TN
Pulling the petcock out was the key. Apparently it had been broken before because the petcock has a turn tab on it. I grabbed the tab with a pair of channel locks and pulled outward gently and it drained like a champ.
As it turns out the lower radiator hose is maybe 5" above the bottom of the radiator and wouldn't have drained the system completely.
I removed 10 quarts of coolant that actually looked pretty good - no cloudiness, etc.
Charlie
As it turns out the lower radiator hose is maybe 5" above the bottom of the radiator and wouldn't have drained the system completely.
I removed 10 quarts of coolant that actually looked pretty good - no cloudiness, etc.
Charlie
