Richard Cope Posted November 6, 2019 Report Share Posted November 6, 2019 Going to be flushing my antifreeze and want to replace the petcock in the engine block, hasn't been opened in years. Like to have one a new one on hand before starting. Does anyone know the thread size, thinking that it is probably 1/4 NPT however not sure. The engine is a stock 201 used in a 1939 Plymouth. Many Thanks Richard Quote Link to comment Share on other sites More sharing options...
Plymouthy Adams Posted November 6, 2019 Report Share Posted November 6, 2019 if in doubt, pull it, carry it to your local parts house....they match you up easily.....the ones I have are 1/4 NPT 1 Quote Link to comment Share on other sites More sharing options...
dpollo Posted November 9, 2019 Report Share Posted November 9, 2019 the most common block drain is a simple butterfly handled valve available new at most any auto supply. as PA says 1/4 pipe thread 9/16 wrench needed Quote Link to comment Share on other sites More sharing options...
Don Coatney Posted November 9, 2019 Report Share Posted November 9, 2019 10 hours ago, dpollo said: the most common block drain is a simple butterfly handled valve available new at most any auto supply. as PA says 1/4 pipe thread 9/16 wrench needed Same one I installed in this oil filter. 1 Quote Link to comment Share on other sites More sharing options...
Richard Cope Posted November 9, 2019 Author Report Share Posted November 9, 2019 Thank everyone for your replies, Evans antifreeze was put in the engine after being rebuilt many years ago, however less than 4,000 miles . Last summer Evans tested and indicated that it was till good, however with the age want to give it a flush. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.