Yummybud924

I just noticed my drain plug is leaking. it is not the original porsche one. I replaced it last year with a m10 x 1.5 plug from napa. it doesn't have the o ring like the orignal but has a rubber gasket and it was fine till now.

I tried tightening it and it just turns and turns...... so i'm guessing the threads are bad. I haven't taken it out yet but i think the threads in the rad might be stripped and not the plug. I want to fix this tomorrow so I can drive teh car.

I don't mind permanently bonding or glueing the plug in there as I can just drain the rad by removing the lower rad hose.

I will go and buy another m10 plug tomorrow (I can't get the original porsche one this weekend). and if it doesn't go tight like this one then i want to glue it in somehow to prevent it from leaking or worse blowing out while i'm driving.

the rad is fairly new and was replaced 5 years ago.

I have some glue called automotive goop which is pretty strong and bonds and seals almost anything but its temp range only goes up to 150 F. would the rad plug get up to this temp?

i was also thinking of using radiator fix expoxy on the plastic drain plug and screwing it in but not sure if it would work.


any ideas?

BlackOp

Mine did that recently...turns out the very end of it had broken off inside the radiator. Left me stranded when it backed out and dumped all my fluid..good times.

Paulyy

you'll want something that goes over 220F my water temp sensor sits around 180F

if you can fix the thread, go to one of them stores that stock screws, nuts, bolts, washers ect and get some copper washers and use them. aluminium ones if you want.

Yummybud924

I could use rtv sealant but i'm worried that won't be strong enough to keep the plug from possible blowing out in the future if the threads are too stripped.

I was thinking of some epoxy made for plastic. permatex makes a 2 part epoxy for plastic but it says it works for most plastics and it may not work for my appliction.

is there a lot of pressure at the plug? is it likely to blow out if the threads are stripped enough to let the plug keep on turning without getting tighter?

thanks.

Jfrahm

Yes, the cooling system is under pressure and it'll probably blow out. I have fixed cracked radiators in the past with JB weld and I feel that if you JB weld the bolt in properly it'll seal just fine until you get around to replacing the radiator. You might also tap it oversize or timesert it or something. A 1/4 NPT might just fit.

xsboost90

i would be nervous about tapping that out larger. I would clean the hole out with some brake clean or something to remove the antifreeze residue and put some JB weld on the plug- you may be able to retap the hole and insert a longer plug also to reach threads further back. Putting a crush washer on there wont work because it'll strip the threads before it crushes the washer.

ZW 944

I installed the LR hose & ball valve drain to that spot, and its been awesome. Any time I want to work on the car, I just drain all the coolant into some gallon jugs, and its easy, and mess free. no leaks.

LuigiVampa

As the others have mentioned JB Weld is the way to go here.

87 944 C

i just always used the lower hose to empty the radiator.

find a bolt that fits, jb weld the bolt and thread it in. or go like 1MM to big and force it to go in.

Yummybud924

problem with jb weld is that it says on the package not meant for plastic. also the plug is a different type of plastic than the rad so i'm worried that even a product made for "most plastics" won't bond it properly.

once I put it in there is no way to know if it is properly cured.

jb weld is an epoxy so i'm going to go and check to see what I can find find for plastic.

I've just seen permatex two part epoxy for plastic. and again it says "works for most plstics".

Yummybud924

I just checked the jb weld website and also the permatex and they both say that it won't bond to some plastics.

NOTE: Will not bond most polyethylene or polypropylene plastics.

how would I know if my rad or plug isn't made from this type of plastic?

xsboost90

not sure but when i knocked a hole in our radiator at a race with the mounting bolt, we JB welded a bolt into the hole and it lasted the rest of the year until i swapped radiators.

V2Rocket

you could try melting it together...lol

the drain plug plastic will soften if you stick a soldering iron in it - this is how you remove the threaded portion when the hex part breaks off. i'd imagine that not much more heat would start to goo the rad tank as well.

Yummybud924

I couldn't find a m10 x 1.5 drain anywhere. so I bought a m10 metal bolt and put 2 o rings on it and a washer but i'm not sure if putting a metal bolt in a plastic housing is a good idea....

also bought jb weld qwik but i'm also hesitant to use that.

Tom M'Guinn

Where are you located?