View Full Version : Plastic Rad Tank drain cock leaking

05-06-2009, 03:29 PM
Seen posts about replacment drain cock, help numbers etc.

Mine is not broken, it just gets very difficult to tighten, and leaks when the system is hot under pressure.

A few nights ago, I took it out, put grease on it, and put it back in, it is still leaking. I put an Oring on it but there REALLY is not a good surface for the Oring to seal against. I do not know if it is leaking past the actual threads, or through the drain tube itself.

Any suggestions?
How likely is it that one of these replacement parts might fix the problem, when I can't really see anything wrong with the old one.


Scott Long
05-06-2009, 04:21 PM
I got one from Autozone for like $2.00 that is listed on the box for a Toyota. It fits my radiator perfectly and mine is a ford replacement radiator.

I don't have the part number off the top of my head though, but go into the autozone section where they have the radiator caps and overflow bottles and there should be a white plastic drain cock for a toyota. What I did was buy one of each different one they had since they were cheap, found one that fit, and then took the rest back. Then I bought a spare of the one that fit.

Scott Long
05-06-2009, 04:23 PM
If yours is plastic the threads wear down a bit and the heating and cooling of the plastic makes it fit worse over time.

Worst case, if you can't find one to replace it, have the hole plugged by a radiator shop, they can braze it shut for cheap. Then when you need to drain it, just loosen the lower rad hose and drain it that way.

I've seen that done too.

Either way, this should be an easy fix. :D

05-06-2009, 07:08 PM

05-06-2009, 07:59 PM
i used a nissan one... it stripped shortly after... i plan on going to ace and getting a stainless bolt and an oring to replace it. :)

05-06-2009, 08:18 PM
got one 4th place tried tonight.
Looks promising as it has a big flat area for the rubber washer to seal against.