What?!

[KongGMC]

Alright so before I turn my 87 Toyota Supra into a roaring bonfire in the front yard, I wanted to see if I could get some help. I am 99% complete with my BHG repair and after pouring a 2 quarts of coolant into my radiator I here it running out somewhere else. It is leaking out of the coolant drain cock on the side of the engine block. It only took a few turns or so I thought to get the thing loose enough to allow it to drain all of the coolant out. I've now tightened it up until there are no longer any threads left and have also partially rounded out the end of the drain cock torquing it down so hard. No matter how hard I torque it down, it still leaks coolant out.... and now I can't really get it any tighter without breaking it permanently. Any and all tips are welcome.:cry:

 

[benchwarmer]

Uh, teflon tape? How bad is it leaking? If it's a small leak teflon will seal it up no ploblem. Or you can get a copper crush washer.

 

[KongGMC]

It leaks out of the center of it. Is there supposed to be a bolt in it? I thought it was just like a bleeder valve on your caliper where it allows stuff to pass through when it is loosened up. If you think that stuff will fix the problem I'll try it but how will teflon or a washer keep coolant from coming out of the center?

 

[CyFi6]

There is supposed to be a bolt in it. Theres a brass part that screws into the block, and theres a bolt part that screws into that fitting to plug it off.

 

[suprarx7nut]

You should be using a thread sealant (like permatex's) IMO, or teflon tape I guess.

I never realized the drain cock was a two piece bolt. :dunno:

 

[gaboonviper85]

Stick some gum on it...all fixed

 

[KongGMC]

Yeah I don't remember taking a bolt out of it and I put all of my bolts in bags and I'm out of bolts now, LOL! Any ideas what size bolt it might happen to be?

Also, PLEASE don't get angry with me cause I'm just thinking here, but I've got the drain tightened ALL THE WAY DOWN so that there are no more threads left to go into the block and when you pour coolant into the radiator quickly/steadily and then go around to the side of the engine and look at it, it's pouring out just as quickly as you poured it in. It's not a leak, the bolt isn't even trying to stop the coolant.... like I never even tightened it down to begin with. I am so close to being done with this thing and this had me near bout devastated last night. Again any help is awesome.

If I can't get this figured out what do ya'll think of something like water proof JB Weld? I know that sounds EXTREMELY red neck and it's probably the most rediculous thing you could do but I'm selling the car. Although I don't want it to leak for the guy who is buying it either.

 

[AJ'S 88NA]

Some time with petcocks, you have to unscrew it to get it to seal, have you tried to turn it counterclockwise all the way out to see if it stops?

 

[IJ.]

Tape or sealant where it screws into the block.

You don't need anything on the plug as it has a tapered end that seats when screwed in.

 

[jetjock]

^ What he said although I've seen a few 7Ms that don't have that setup and use a bolt instead. I add real petcocks to those when I find them but most have the tapered seat type.

 

[IJ.]

I put a plug in mine

 

[jetjock]

What, no Devcon?

On the bolt types I drill and tap 1/8 NPT in the bolt and install a brass petcock. It beats wrestling with the stock setup when the engine is hot. Gets a bit toasty in that area you know...

 

[CyFi6]

There is an outer brass thing that screws into the block, on the side of it there is a hole. There is a bolt that screws down the center of the outer part, when you unscrew the center part, before it comes all the way out it reveals the hole, allowing the coolant to come out. You never have to fully remove the center bolt. You can screw in the out part into the block as hard as you want, put as much sealer as you want, as much jb weld as you want, but there is still a gaping hole in the center.

 

[suprahabsfan]

Let me know if you are gonna junk your car. I'll take it off your hands :sarcasm:

 

[KongGMC]

There is an outer brass thing that screws into the block, on the side of it there is a hole. There is a bolt that screws down the center of the outer part, when you unscrew the center part, before it comes all the way out it reveals the hole, allowing the coolant to come out. You never have to fully remove the center bolt. You can screw in the out part into the block as hard as you want, put as much sealer as you want, as much jb weld as you want, but there is still a gaping hole in the center.

You seem to be describing this a lot better than the others. Although everyone's feedback is greatly appreciated. I've been trying ALL morning to find a bolt that fits inside that drain cock hole but couldn't find anything. I think it's a 13mm bolt which nobody sells around here. I tried several 12mm bolts which just fall into the hole and the 14mm's won't thread in. I bought one of those 1/2 inch rubber plugs that you use when the oil drain pan get's stripped out. Gonna try that tonight. Any idea what the thread size if of the center of that drain cock just incase this rubber plug doesn't work?

 

[IJ.]

JJ: LOL nah that's the devil's tool! (I like being able to undo things again)

Kong: From memory it's M14x1.5 (I'd have to check to be 100% sure though)

Late model motors just have a plug there, I can't get to mine with the headers on anyway.

 

[gofastgeorge]

I bought one of those 1/2 inch rubber plugs that you use when the oil drain pan get's stripped out.

Man, that is risky.
Oil pans don't develop much pressure in them.
Hate to see you roast it down by having the rubber thing pop out and you not catch it in time.....
Why not just put a brass pipe plug in the block.
Any hardware store has them.
Caution !
Japanese pipe threads are just a tad smaller then US pipe threads,
and often require you to run a tap in a few turns more to open the size up.
Otherwise they just catch like one thread.

I have one of the original valves here, from a block I scrapped......
The center 'bolt' is 14 x 1.5 thread.
(good memory, IJ !)
But it is not quite a bolt.....
It has a tapered end, like a valve (which it really is).
And the end butts up against a tapered seat in the body.

If you can wait a few days to get it, I'll sell you this one.

 

[CyFi6]

its likely a BPT tapered thread, rather than the normal NPT. They are ever so slightly different.

 

[KongGMC]

Alright well I bought 2 different M14x1.5 plugs and tried threading them into that bolt hole to no avail. I don't know if maybe the threads in it are boogered up or what but it's like it's too big. The 1/2 inch plug didn't work... it was too big. I ran back and forth to the hardware stores ALL morning and couldn't find a bolt that would work in it. To make matters worse the Toyota dealership here is retarded. They don't have ANYTHING in stock for a Toyota Supra, to include that plug. Earlier I tried removing the drain cock from the block but unfortunately, I put a lot of buttox into it and it is impossible to get off without removing the exhaust manifold. However if I can just find something that will make a suitable plug for it that would be awesome.

I guess tomorrow might go get another one of those M14x1.5 plugs and see if I can get it to thread in there.... might take a wrench to it and see if I can help coax it in without crossthreading it. Are ya'll sure it isn't like a M14x1.25 or even an M13xwhatever?

 

[IJ.]

The hole in the block could possibly be 3/8 Bspt I'll check tomorrow.