I have looked high and low for a replacement radiator petcock for my 2004 jeep grand cherokee limited 4.7l v8 and have come up empty handed. Closest thing I found was Dorman 61134. It popped off going down the road so I am out of luck. Cant really move forward until I have a replacement. I would hate to be in the position where I have to buy a whole new radiator. If anyone knows a part number for this I would be eternally grateful!

(And it is a plastic petcock, not metal. Looks just like aforementioned part number)

 

Have you tried a dealer for it?

 

Try taking a walk through a junk yard and pick one off an existing radiator. Thats what I came up with....

 

I was told by my mechanic not to use it because they've had a lot of trouble with them leaking. He said just pull the lower hose to drain it. You can contain the coolant if you're careful. He does that on all vehicles.

 

The drain petcocks have failed on me also. I stopped using them and drain fluid by removing lower hose.
When my XJ spit out and lost its petcock, I used 'marine grade epoxy putty' to fill the hole. It was leak free until vehicle was scrapped over two years later.

 

I have caught them leaking, drips. The main component in these radiators is nylon. If you look at your radiator, the spot where the petcock goes is a lip. It's relatively thin material and even thinner where the groves are for the threads on the petcock.. With exposure to repeated heating's and pressure they fail slowly over time. I have had to keep an eye on mine as the radiator ages.
I have never had one fall out though.

 

That's also another place for a mystery coolant loss. If it's slow enough, you'll never notice it. In addition, on my WJ, it's directly in line with the A/C drain so it's hard to tell which one is making the puddle on the driveway.

 

Thanks for all the replies. And no, I haven't tried a dealership yet but I will ask them. The marine grade putty sounds like a good fix for the moment; I did something similar with exhaust leak. The search will continue. Thanks all!