86 radiator drain plug
Thread Starter
Heel & Toe
Joined: Dec 2013
Posts: 23
Likes: 0
86 radiator drain plug
I have the radiator with the plastic ends, the plug has come loose on me twice now while driving, the first time I thought it was the radiator that blew out, I pulled it and checked it out and could not find any leaks so I put it back in and it was fine for a couple weeks, this time I hit a bad spot on the highway pretty hard bump and it came loose again. Now it will not seal up, it just keeps turning. Has anyone had this problem, do these plastic plugs strip out, there are no signs of damage to the plug. 
Team Owner
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
I've never had that problem; just the opposite as it takes plyers to loosen it to drain the radiator.
Is this a new issue? If the plug is ok I would suspect the threads in the tank.
Is this a new issue? If the plug is ok I would suspect the threads in the tank.
Team Owner
Joined: Sep 2003
Posts: 25,373
Likes: 2,734
Here's an Amazon link to the correct drain plug if your radiator is OE/GM and you just need to buy a replacement. You can do a "mouse over" to zoom it. There should be no issues with replacement. It should be "on the shelf" at a local dealer of ACD jobber using the same 3056858 part number:
I gave you the link so you could see how it's constructed. Bought "local" I'd think $8 or less.
I gave you the link so you could see how it's constructed. Bought "local" I'd think $8 or less.
Le Mans Master
Joined: Aug 2007
Posts: 8,735
Likes: 412
From: WV
You have to replace the drain plug, but I never use the drain plug on the radiator, it takes forever to drain that way.. It works better for me to just pull the hose off at the bottom connection and let it drain into a pan...This method drains the radiator in about 15 seconds and there is no chance of stripping the drain plug, plus it allows any crap in the radiator and block to drain out the larger hole..Stick a hose in the filler hole and flush out the radiator while your at it.........
...WW
...WW
Last edited by WW7; Jun 15, 2014 at 11:44 AM.
Melting Slicks
Joined: Aug 2008
Posts: 2,082
Likes: 50
From: Palmdale CA
I picked this one up at NAPA, back when I had the plastic radiator..
double check the P/N mine was for an 95
You need to squeeze the plastic anchors with a pair of needle nose pliers, and the petcock comes right out.
double check the P/N mine was for an 95
You need to squeeze the plastic anchors with a pair of needle nose pliers, and the petcock comes right out.
Thread Starter
Heel & Toe
Joined: Dec 2013
Posts: 23
Likes: 0
Drain plug
Is the drain plug suppose to tighten down to a stopping point or does it turn to a certain point to seal and if you keep going it will open back up? The plug that is in it now pulls rite out without squeezing the tabs in.
Last edited by kprowler8; Jun 15, 2014 at 06:57 PM. Reason: Add to
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)
Joe Kucinski
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
10 Revolutionary 'Corvette Firsts' Most People Don't Know
Joe Kucinski
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2
Michael S. Palmer