Radiator petcock replacement
Thread Starter
Instructor
Joined: May 2007
Posts: 199
Likes: 2
From: Toronto
Radiator petcock replacement
Changing my balancer, etc. Went to drain the coolant, and PO or backyard Bob must have messed up the petcock.
Ordered a new one from GM. How does the old one come out? What I see right now, is a plastic cone about 1/4 inch long, and underneath that is a rubber gasket/grommet of some sort. Inside the cone I was expecting to see a square and allen head recess, but it looks all messed up.
I yanked the lower rad hose to drain the coolant.
Does the rad have to come out to change the petcock?
Thanks!
J
Ordered a new one from GM. How does the old one come out? What I see right now, is a plastic cone about 1/4 inch long, and underneath that is a rubber gasket/grommet of some sort. Inside the cone I was expecting to see a square and allen head recess, but it looks all messed up.
I yanked the lower rad hose to drain the coolant.
Does the rad have to come out to change the petcock?
Thanks!
J
Tech Contributor
Joined: Jan 2007
Posts: 19,401
Likes: 1,144
From: Dyer, IN
Changing my balancer, etc. Went to drain the coolant, and PO or backyard Bob must have messed up the petcock.
Ordered a new one from GM. How does the old one come out? What I see right now, is a plastic cone about 1/4 inch long, and underneath that is a rubber gasket/grommet of some sort. Inside the cone I was expecting to see a square and allen head recess, but it looks all messed up.
I yanked the lower rad hose to drain the coolant.
Does the rad have to come out to change the petcock?
Thanks!
J
Ordered a new one from GM. How does the old one come out? What I see right now, is a plastic cone about 1/4 inch long, and underneath that is a rubber gasket/grommet of some sort. Inside the cone I was expecting to see a square and allen head recess, but it looks all messed up.
I yanked the lower rad hose to drain the coolant.
Does the rad have to come out to change the petcock?
Thanks!
J
Tech Contributor
Joined: Jan 2007
Posts: 19,401
Likes: 1,144
From: Dyer, IN
There are a couple of different types. One as you stated, has accepts a 1/4" drive, and the other just has wings on it so it can be turned. Sounds like the wings have been broken off. Post a pic if you can.
Last edited by lucky131969; Jan 23, 2025 at 10:13 AM.
Burning Brakes
Joined: Aug 2006
Posts: 753
Likes: 2
From: Denville NJ
You need to look up and behind the cone where the fluid comes out of. Then you will see the infamous white plug/valve which looks like nothing that you ever seen. It faces the lower area of the engine.
As noted above, a 1/4" driver will open it with a quarter turn counter-clockwise. Do this cold or else.
If you wiggle it a bit after the quarter turn, you can pull it out while twisting it lightly a bit more. Of course you need to have a drain pan ready to catch it all. It can be a bit messy but a real problem when it's hot. There is a replacment valve with "wings" on it which you may be able to order from Autozone, to make future drains much easier. Good luck!
As noted above, a 1/4" driver will open it with a quarter turn counter-clockwise. Do this cold or else.
If you wiggle it a bit after the quarter turn, you can pull it out while twisting it lightly a bit more. Of course you need to have a drain pan ready to catch it all. It can be a bit messy but a real problem when it's hot. There is a replacment valve with "wings" on it which you may be able to order from Autozone, to make future drains much easier. Good luck!
Tech Contributor
Joined: Jan 2007
Posts: 19,401
Likes: 1,144
From: Dyer, IN
Force not required ! Just turn 90 degrees CCW and pull out. There is small metal pin that acts as a retainer.
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