View Full Version : Difficulty Getting plugs back in after winter

03-27-2010, 08:38 AM
Hey - Is there a way to ease getting the plugs back in the block . Can you use a wire brush on the threads. I greased all the plugs and threads last fall but they are still difficult to turn all the way in.
Is there a marine thread cleaner?

03-27-2010, 09:30 AM
spark plugs?

If it is the spark plugs-why did you leave them out all winter long?

03-27-2010, 10:35 AM
I think he's referring to the block plugs for draining the water out of the block. I left mine out all winter too and had a little trouble getting them back in as well. I ended up using a small wire brush and went really easy so I wouldn't mess those threads up. It didn't take much to get that rusty gunk that built up right by the hole out. You'll get er, you just got hold your mouth right.

03-27-2010, 07:58 PM
Thanks. Was not spark plugs just block plugs for draining .

03-27-2010, 08:13 PM
These plugs are difficult and I think it's because there is no relief on the block. I mean you have to line them up exactly right and if you have a little corrosion then it's even worse. Now what you can do is set your self up a petcock in this location so all you have to do is open the valve, just like on the old copper radiators. You just need to head down to Lowes with the block plug in your hand to match up the pipe threads and if you are good with plumping supplies just let the guy at Lowes know and he should be able to set you up!

03-27-2010, 10:29 PM
or just put a union with a ball valve on, or after you drain apply vaseline and reinsert plugs

03-27-2010, 11:34 PM

Ah.......hummmm.....isn't that what I said?? I think tomorrow I will go and measure what size pipe thread the plugs are and come up with a Bill of Material (BOM) for this task. I set up my MasterCraft that way but I haven't gotten around to converting the Moomba yet. And most somewhat mechanically inclined folks have grease or anti seize in their garages. You are going to make some wives unhappy when they can't find their vaseline. :)

03-28-2010, 12:51 AM

no it wasn't what you said....a petcock valve is usually 90 degrees, and a ball valve straight and easier to clean back into the block with a piece of wire to dislodge and clear any internal rust blockage. Very difficult to do that with a petcock valve. If you meant a 180 degree petcock valve , good luck finding one big enough to allow proper drainage, but if you can then i guess my def'n are wrong and i did say the same thing

03-28-2010, 10:41 AM
actually I haven't said anything specific there is just the idea in my head that I need to put a valve in this spot like my MC had. Not sure yet what the pipe thread is, what kind of clearance I have between the block and the stringer or anything. I too like ball valves as they are simple and easy to use and I doubt I will be able to find a petcock valve (ok MSC or McMasterCarr but I just want a simple trip to Lowes). But as of yet there is NO BOM materials in my head as I don't even have my first cup of coffee yet and until I get that nothing is going to happen! :D

03-28-2010, 10:54 AM
OK, quit argueing! :p A petcock valve can be straight, 45 or a 90, there! Actually one of the best things i found to use was a straight brass radiator drain valve for a 70's-80's era vehicle. Same thread and you just screw it in and water flows, screw it out and it's sealed. Never have to remove anything. You can even put a hose on the end of some to direct to the bilge.

03-28-2010, 11:06 AM
oh I feel so much better now I have had a cup of coffee!!! Hey I am NOT arguing with anyone. Pretty much going to put something on the block in the next week or so just to make things easier but now I think the trip has to wait until I get some bacon! :p

But I think we ALL agree WE ALL have a GOOD IDEA here! Hummmm.....maybe I can make a kit and sell them! You know I can get some Mil-spec stuff!!!!! :razz:

03-28-2010, 11:51 AM
one year I open the supplied valve on my indmar block and very little flowed out the screw valve......so i removed it completely and was amazed how much rust and debris had settled inside the block around that hole.....thats when i replaced those little valves with a larger greater flow ball valve that i could easily stick a wire thru and and clean out around the inside of the block.....my fear was having any water trapped inside and freezing due to the low temps we get up here....lucky i had enough room for a threaded union and a ball valve on my 99ls........,now with my vdrive and knocksensors and less room I just take the whole thing off, drain,antisieze cmpd and reinstall. Once the water is out why not reinstall them at that time , quicker spring start up?

04-02-2010, 12:22 AM
Go to NAPA and buy a T-302 1/4" pipe tap. Work it carefully back and forth by hand into the threaded block hole and it will clean the threads right up so that you can put the block plug back in. Squirt a little wd40 on the threads to help it along.

Looks like this:


04-12-2010, 01:42 PM
Bought the 1/4 threaded tap and used it with some penetrating oil, worked perfectly. My knuckles really wish I would have tried that sooner. Thanks for the info.

04-25-2010, 03:13 PM
Where do you get these? Lowe? Home Depot? Plumbing supply store? Does anyone have a picture of one of these so I know what I'm looking for when I see it?

How about the straight brass radiator drain valve for an 80's car. Where would I get one of those?