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I tried removing one of the plugs for my heater lines yesterday. I'm not going to do that actual work until the weekend, but just wanted to see if I can get the plugs off. I've doused them with liquid wrench several times now, figuring that might help when it comes time to remove them. I tried loosening the plug from the bottom radiator pipe but no luck. Any tricks I can try?

Hi Nick,

I drained the engine, removed the tube, put it in a padded vice, then I used the longest breaker bar I had with a socket. After a good soak, I tried tightening just a bit before trying to back it out. When it started coming out, I'd half-turn out, then quarter-turn back in to relieve the stress on the plug. After a full turn, it came out easily. A combo wrench wasn't enough leverage to get it started. You might try a judicious application of heat, first.

I used anti-sieze on everything while putting it back together. The dissimilar metals, in a liquid emvironment, can be a corrosion nightmare over time.

Another thing I discovered with radiator hoses was smearing a dab of silicone grease on the fitting where the hose is going to go. The hoses come off so much easier the next time you need to pull them. I haven't had to cut a hose off since I started doing that.

Good luck,

Dave

DaveO;

Thanks for the tips. I was thinking of placing a large flat screwdrive I have against the tube to apply pressure with one hand, while using a wrench on the other to lossend plug. I was thinking of using my small breaker bar to get things moving as well. Don't really relish removing the whole tube if I can get away with it, but will if its a must. I guess same procedure works for block plug as well?

Nick,

Using your screwdriver to leverage against might work fine. There isn't a whole lot of room to work right there. I was changing my hoses at the time I was installing the heater, so it wasn't that big of deal just to pop it in a vice.

I was also very careful with the head plug. It was probably the original unit, and there were some corrosion issues. I was able to work it loose with patience. I don't remember if mine had a brass or a black iron plug, I just remember that I was concerned with stripping the head threads.

Have fun...

Dave

Using an air impact wrench with an 8 point socket on the square head plugs will put the torque right where you need it. This way you can forget about the screw driver as a pry bar, just hold the pipe with your hand. Remember these are tapered thread plugs, once they move a little, it's free. Assemble new fittings with Permatex high temp thread sealer, this acts as a sealer & anti-seize lube. The plug on top of the bypass fitting on top of the water pump is easier to deal with & works just as well as a water return port.

Charles;

Thanks. I was also thinking of using my impact gun but wanted to hear from someone else that its OK to use. I had heard that the effect of the impact gun is easier than prying.

I also endorse the 8-point socket since I didn't have one and ended up drilling out the head plug. A PIA it was, too, so I invested in the socket for future use.
Gary

Why an eight point socket though? won't a 6 point allow a square headed plug? Just curious? How hard are 8 point sockets to come by? All I have in my toolbox are 6 and 12 point sockets.

Nickathome wrote:Why an eight point socket though? won't a 6 point allow a square headed plug? Just curious? How hard are 8 point sockets to come by? All I have in my toolbox are 6 and 12 point sockets.

8 point sockets work on square heads only, 6 point will not work on a square head. Any good tool supplier should have them. We have a Craftsman set in both 3/8 & 1/2 drive. They don't get used that often, but are a God send when you need them.

If these ideas dont work out for you try removing them and heating them up. That was the way I ended up having to do mine.

MSeriesRebuild wrote:

Nickathome wrote:Why an eight point socket though? won't a 6 point allow a square headed plug? Just curious? How hard are 8 point sockets to come by? All I have in my toolbox are 6 and 12 point sockets.

8 point sockets work on square heads only, 6 point will not work on a square head. Any good tool supplier should have them. We have a Craftsman set in both 3/8 & 1/2 drive. They don't get used that often, but are a God send when you need them.

12 point sockets will work on square heads. You have to try them to get the right size...
BUT (and I am sure Charles will agree) if the square head bolt, plug, whatever is really stuck the 12 point is more likely to round it off!!!

A 6 or 12 point socket on a square head plug only contacts the four corners of the plug, and usually only after being driven on with a hammer. 8-point sockets contact the majority of the head of the plug which allows for a solid grip. My 8-point was hard to find: NAPA had only the socket I bought and said they weren't obtaining any more because there is little demand for them.
Gary

pfrederi wrote:

MSeriesRebuild wrote:

Nickathome wrote:Why an eight point socket though? won't a 6 point allow a square headed plug? Just curious? How hard are 8 point sockets to come by? All I have in my toolbox are 6 and 12 point sockets.

8 point sockets work on square heads only, 6 point will not work on a square head. Any good tool supplier should have them. We have a Craftsman set in both 3/8 & 1/2 drive. They don't get used that often, but are a God send when you need them.

12 point sockets will work on square heads. You have to try them to get the right size...
BUT (and I am sure Charles will agree) if the square head bolt, plug, whatever is really stuck the 12 point is more likely to round it off!!!

The round off issue is precisely why I didn't mention the 12-point socket. The only wise choice is an 8-point.

I know all about the round off issues, that'swhy I am going to try to locate an 8 point socket. If I cannot however, I am going to try what I can. My only concern is in getting the plugs off without damage to the pipe and the head. If I screw up the top of the plug I don't care, as they will more than likely be going straight into the trash anyway. Once the heater is on and functioning I'm not going back. Yes, I know to save the plugs is a wise idea should the need arise to reuse them, but all I can say is, however it works out.....

Hi Nick,
A lot of good info all the way around on this topic-let me share my PIA story, step by step:

Drain coolant;
No 8-point socket, no way to heat the area around the head;
Corners already rounded on the plug (probably by a 12-point socket);
Open-end wrench's jaws flexed (Craftsman);
12 inch adjustible wrench rounded the plug head even more;
Removed oil filter cannister, and #6 spark plug for more room;
tried a 12 inch pipe wrench (gets tighter as you pull harder) with a cheater pipe-disintegrated the remainder of the square part of the plug head;
No Easy-Out big enough to center, drill, and crank out the plug remnants;
Drilled two smaller holes (1/4 size) into the plug (like an 00 shape);
reamed the center between the two holes;
Used a jigsaw cutting slowly from the center of the now oval hole out toward the head and threads;
Reversed the direction and cut the same path to the other side of the head and threads (so now I have a hole like () but rounder ;
Used a hammer and chisel to drive each half inward toward the other;
Extracted each half with a magnet, to include fishing one down into the head to extract all the cutting material.

That's why I sprung for the 8-point socket afterward.
Gary