Leaking petcock on fresh water coolant side.

[jrbrein]

Hello Everyone,

I have a set of DD 6-71 N's that I am flushing the old fresh water coolant and replacing with new antifreeze. Each engine has 3 petcocks and I was able to open each by hand to drain the old coolant out.

After flushing I closed all 3 petcocks by hand and filled the system with new antifreeze. I immediately discovered one of the petcocks (the one on the bottom of the oil cooler) was leaking so I turned it additional 1/4 of a turn using a pair of plyers. This slowed the leak to a slow drip (3-4 drips per min). My question here is, how much torque can I apply here? The petcocks were recently replaced by my mechanic, Tom Hugg when he filled the fresh water side with an acid cooling flush. I am replacing that solution with DD Powercool antifreeze.

Thanks for any responses!

Jon

 

[Finalee]

Once loosened they should only be hand tight. It's likely trash between the seat. By hand, try loosening and snugging a few times. This might dislodge it.

 

[bobk]

I replaced mine with pipe plugs. No more leaks.

Bobk

 

[jrbrein]

Thank you for those answers.

If I cannot clear the trash, solid plugs are a great idea.

Jon

 

[racclarkson@gmail.com]

A little shot of air will clear it. If you don't have a compressor, a soda straw and your lungs usually works. A can of air works; a stream of water works. Never over tighten.

 

[Bob Bradley]

FWIW, NAPA carries the exact same petcock. I replaced several of mine. I don't recall them being particularly expensive.

 

[SEVEN]

Open and close it a few times to see if the material plugging it clears. If not air then, solid plug.

 

[jrbrein]

Thanks again for the advice.

I opened and closed it several times and that did the trick. I purchased a duplicate petcock at Advance Auto Parts for $3.59 to have ready to go just in case.

Hand tightening was quite enough to stop the flow.

Jon