JD 730 coolant drain plug at bottom of head stuck

[andy r]

I was going to drain the coolant in my John Deere 730 diesel by removing the plug located on the bottom of the cylinder head. I had it out a year or two ago. Anyway it seems stuck. I can not get a pipe wrench to stay on the treads sticking out of the head and a wrench just wants to round off the square head. I have hit it with a hammer a few times and sprayed it with penetrant. I guess I could drive a socket on it. Probably could heat and cool the plug a few times. Any ideas for getting the coolant plug out of the bottom of the head? Thanks.

 

[Pete in MD]

Do you have a square socket?

 

[Rich'sToys]

I had the same problem on one of my 50's. I ended up taking the lower radiator hose off on one end and draining it that way.

 

[andy r]

I should try a square socket. Will have to find one.

 

[wore out]

(quoted from post at 19:59:34 12/10/21) I was going to drain the coolant in my John Deere 730 diesel by removing the plug located on the bottom of the cylinder head. I had it out a year or two ago. Anyway it seems stuck. I can not get a pipe wrench to stay on the treads sticking out of the head and a wrench just wants to round off the square head. I have hit it with a hammer a few times and sprayed it with penetrant. I guess I could drive a socket on it. Probably could heat and cool the plug a few times. Any ideas for getting the coolant plug out of the bottom of the head? Thanks.

IMHO, once you get it out, replace it with the (correct) hex-head plug (A2093R) or a brass plug to make it easier to remove next time.

 

[620 John]

Besides heat about the only other thing to try would be vibrating it with an air hammer (I wouldn't get too aggressive though). I've learned to use anti-sieze when reinstalling those plugs.

 

[Hlmillus]

I had the same problem on my 41 B. I drilled a hole through the center of the plug and tapped it for a 1/8 taper pipe plug. I don't recall the size of the tap drill but check the chart for that. That doesn't fix the problem or get the stuck plug out but gets you by.