VCCA Home Forums TECHNICAL - 1945 AND NEWER 1949-1954 Petcock

Hello everyone, I had a new petcock installed on my 53 235 truck. I went to flush the motor a when I open the petcock nothing comes out. Is there anything I can use to frush or should I insert something into the hole. I don't want to fool with it until I have heard from the experts. The motor does not run hot. Thanks...If
it's not one thing then its another...Oscar

The petcock is located at the lowest point in the block.Rust and sludge also settles at the lowest point and that is what is plugging the hole.If it were mine I would remove the entire petcock to make the opening as large as possible.Then probe around in the opening with a wire-especially working to the front of the engine...The remove the radiator cap and force water into the core and flushing the junk out.I would also do a flush with a good heavy duty cooling system cleaner.The 2 part powdered type is what I use.But do flush as much as you can out of the block so it dosen't plug up the core.

Thanks Gene, I was going to do what you said but wanted to make sure. I didn't want to screw anything up. I did have my radiator boild out not to long ago and did a reverse flush.Do you have a name for the two part powder flush? Thanks again and have a good day...Oscar

It would be in a silver can with the Number 7 name or yellow in Prestone brand.

The 52 had the same problem. I had just recored the radiator and had also flushed the block, had to change some hoses so thought that it would be a good idea to just do a complete drain, opened the petcock and nothing came out, set the air compressor at about 2 pounds, put a rubber tip on the air gun and shot air into the petcock, after doing this 2 or 3 times it began to run but periodically would stop. As Gene says all the gunk tends to settle down there and can be a pain to get rid of.

And if you're not worrried about being completely original, just replace the petcock with a pipe plug. Makes it alot easier to remove the next time you want to flush it.

Bob

Thanks guys, I will try the the Prestone flush and go from there. I am rebuilding another 235 in my front room right now and will be exchanging motors when this one dies. Just want to keep it going as long as possible. Thanks again...Oscar