Block Drains

az'03Silverado · October 6, 2006

I was just curious. It's about that time. I'm getting ready to flush the thing and the block drain on the driver's side looks pretty easy to get to but the passenger-side plug is behind the starter so it looks tough. Also, any other problems? Do they come out easy or are the in there at like 200 ft-lbs. Any with experience please post. I'm still debating. Thanks for your help.

Oh, and Bish, I plan on back flushing using your PVC trick.

ZZebes · October 6, 2006

I think they are called Freeze plugs and i do remove them.

crazymjb · October 6, 2006

If you are talking about freeze plugs you may as well replace them as I believe they are no more than a dollar a piece.

Through some recent web research I have found that they can "sieze" in there and one site recomended punching a hole in the center, inserting a screwdriver, and prying them out like that if that is the case. Otherwise, you could try hitting it on one of the edges with a screwdriver and hammer to pry it out.

When replacing them use a socket that fits in the plug and in turn hit the socket, which should insure good fitment. Also use some blue silicon.

Mike

Rolandd · October 7, 2006

Block drains and freeze plugs are too different things. The block drain is a small threaded plug that allows one to drain the water jacket around one bank of cylinders. Freeze plugs (properly called casting plugs) are pressed in as described above. Usually freeze plugs last the life of an engine, although I have replaced many and they are a PITA to get to some times.

If your coolant is in good shape and you are replacing your coolant with the same type (red or green or blue) you should not need to drain the block. Just pre-mix your coolant before adding it after draining the radiator so that you get the correct mixture. If you are changing the type of coolant then you will want to drain the block and blow out the heater core(s) before adding new mix.