C3 Tech/Performance V8 Technical Info, Internal Engine, External Engine, Basic Tech and Maintenance for the C3 Corvette
Sponsored by:
Sponsored by:

Drain Cock for 81

Thread Tools
 
Search this Thread
 
Old Apr 24, 2009 | 02:05 PM
  #1  
Bullet81's Avatar
Bullet81
Thread Starter
Intermediate
 
Joined: Feb 2007
Posts: 41
Likes: 0
From: Dallas GA
Default Drain **** for 81

In the middle of draining my radiator on my 81 and I am having to do it by loosening the bottom clamp and letting it drain slowly into an old milk jug. (Already have two milk jugs filled and working on a third)

Where is the freakin drain plug on the 81???? I searched this forum but did not see an answer. Heck I even have the Factory Service Manual and cannot find a answer to my question. It only says to drain the radiator by using the drain **** but makes no mention as to where to find it.

I am in the process of flushing the radiator and replacing the hoses but the drain is taking forever.
Reply
Old Apr 24, 2009 | 02:29 PM
  #2  
KapsSA's Avatar
KapsSA
Safety Car
20 Year Member
Active Streak: 60 Days
Active Streak: 90 Days
Top Answer: 1
 
Joined: Jun 2004
Posts: 4,360
Likes: 221
From: Beecher Illinois
Default

There should be a brass plug on the pass side. No petcock.
Reply
Old Apr 24, 2009 | 02:56 PM
  #3  
Bullet81's Avatar
Bullet81
Thread Starter
Intermediate
 
Joined: Feb 2007
Posts: 41
Likes: 0
From: Dallas GA
Default

Yeah I have looked all over the passenger side and still no luck. This is the first radiator that I have not been able to find the drain **** on. I am letting it cool back down from the flushing right now and then I will just take off the bottom hose again and drain and refill.
Reply
Old Apr 24, 2009 | 03:21 PM
  #4  
Ganey's Avatar
Ganey
Race Director
10 Year Member
 
Joined: Apr 1999
Posts: 11,520
Likes: 13
From: CORVETTE 77 385 C.I. TEXAS
Default

Look from bottom, underneath of rad. pass. side.
Reply
Old Apr 24, 2009 | 03:25 PM
  #5  
Bullet81's Avatar
Bullet81
Thread Starter
Intermediate
 
Joined: Feb 2007
Posts: 41
Likes: 0
From: Dallas GA
Default

It is all smooth under the entire radiator. All I can see is the bottom bracket or cradle that the radiator sits on. The only bolts visible are the ones holding on the air dam.
Reply
Old Apr 24, 2009 | 03:44 PM
  #6  
Ganey's Avatar
Ganey
Race Director
10 Year Member
 
Joined: Apr 1999
Posts: 11,520
Likes: 13
From: CORVETTE 77 385 C.I. TEXAS
Default

I assumed KapsSA had 81- profile shows 78 & 79.
Looking from front bottom see the rad. hose connection on end of rad., directly up to the bottom of the rad. is where ours are.
Maybe changed for your yr. or rad. changed.
Reply
Old Apr 24, 2009 | 03:45 PM
  #7  
TimAT's Avatar
TimAT
Le Mans Master
15 Year Member
Liked
Loved
 
Joined: Oct 2006
Posts: 7,123
Likes: 433
From: Gladstone MO
C3 of Year Finalist (appearance mods) 2019
Default

Look on the driver's side- either a plug/petcock on the bottom or on the back. Rarely they put one on the pass side because of the hose. If someone replaced the radiator in the past, all bets are off.
Reply
Old Apr 24, 2009 | 03:48 PM
  #8  
Bullet81's Avatar
Bullet81
Thread Starter
Intermediate
 
Joined: Feb 2007
Posts: 41
Likes: 0
From: Dallas GA
Default

Don't know if if has been replaced or not. I looked all over on both sides and in the FSM before asking my question and could not find it. Almost done with the flushing process.
Reply
Corvette Stories

The Best of Corvette for Corvette Enthusiasts

story-0

Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)

 Joe Kucinski
story-1

Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!

 Verdad Gallardo
story-2

Top 10 Corvettes Coming to Mecum Indy 2026!

 Brett Foote
story-3

Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!

 Michael S. Palmer
story-4

10 Revolutionary 'Corvette Firsts' Most People Don't Know

 Joe Kucinski
story-5

5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2

 Michael S. Palmer
story-6

2027 Corvette vs The World: Every C8 vs Its Closest Competitor

 Joe Kucinski
story-7

10 Most Common Corvette Problems of the Last 20 Years!

 Joe Kucinski
story-8

5 MOST and 5 LEAST Popular Corvette Model Years in History!

 Joe Kucinski
story-9

2027 Corvette Buyer's Guide: Everything You Need to Know!

 Joe Kucinski
Old Apr 24, 2009 | 06:22 PM
  #9  
KapsSA's Avatar
KapsSA
Safety Car
20 Year Member
Active Streak: 60 Days
Active Streak: 90 Days
Top Answer: 1
 
Joined: Jun 2004
Posts: 4,360
Likes: 221
From: Beecher Illinois
Default

Originally Posted by Ganey
I assumed KapsSA had 81- profile shows 78 & 79.
Looking from front bottom see the rad. hose connection on end of rad., directly up to the bottom of the rad. is where ours are.
Maybe changed for your yr. or rad. changed.
Well, for what it's worth, here it is on a 79...

I replaced the brass plug with the petcock.
Reply
Old Apr 25, 2009 | 09:19 AM
  #10  
Bullet81's Avatar
Bullet81
Thread Starter
Intermediate
 
Joined: Feb 2007
Posts: 41
Likes: 0
From: Dallas GA
Default

Thanks for the pic my friend that confirms it for me. Mine does not have a drain ****. There is nothing there on my radiator on either side. I have always suspected that my car has had some front end damage so maybe it was bad enough that the owner had to have his radiator replaced.

The car fax that I ran on the car before I bought it did not show an accident and it checked out as good. However, there were some suspicious lengths of time where the car was not even registered early on in its life in Tennesee. The guy I bought it from said that was probably because the original owner probably just had it stored therefore not registered. I find that hard to believe.

Maybe I will try to track down the original owner and see if he is willing to talk to me about the car or maybe even share some old photos of the car with me.

Thanks for the help guys
Reply
Old Apr 25, 2009 | 10:58 AM
  #11  
pacrimmat's Avatar
pacrimmat
Advanced
 
Joined: Nov 2007
Posts: 54
Likes: 0
Default

Look up from the pass side, about 3" in from end.
there will be a slotted plug about 1/2" in diam. It will be flush with rad surface. easy to miss as its black in color. Drove me nuts for about 5 min on my 76.
Reply
Old Apr 25, 2009 | 11:31 AM
  #12  
Bullet81's Avatar
Bullet81
Thread Starter
Intermediate
 
Joined: Feb 2007
Posts: 41
Likes: 0
From: Dallas GA
Default

Originally Posted by pacrimmat
Look up from the pass side, about 3" in from end.
there will be a slotted plug about 1/2" in diam. It will be flush with rad surface. easy to miss as its black in color. Drove me nuts for about 5 min on my 76.
Ah ha, now that changes things a bit. Next time I have it on the jack stands I will be sure to check again. There is no way I can check without it being on the stands because as most of you know, the front is so low to the ground I can't even get my head under there lol.
Reply

Get notified of new replies

To Drain Cock for 81





All times are GMT -4. The time now is 12:01 PM.

story-0
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)

Slideshow: Ranking the top 10 Corvette engines by torque output.

By Joe Kucinski | 2026-05-05 11:58:09


VIEW MORE
story-1
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!

Slideshow: A Corvette pace car nearly matching IndyCar speeds sounds exaggerated, until you look at the numbers.

By Verdad Gallardo | 2026-05-04 20:03:36


VIEW MORE
story-2
Top 10 Corvettes Coming to Mecum Indy 2026!

Among a rather large group of them.

By Brett Foote | 2026-05-04 13:56:44


VIEW MORE
story-3
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!

Slideshow: the top 10 things Corvette owners want in the C9 Corvette

By Michael S. Palmer | 2026-04-30 12:41:15


VIEW MORE
story-4
10 Revolutionary 'Corvette Firsts' Most People Don't Know

Slideshow: 10 Important Corvette 'firsts' that every fan should know.

By Joe Kucinski | 2026-04-29 17:02:16


VIEW MORE
story-5
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2

Slideshow: Should you buy a 2020-2026 Corvette or wait for 2027?

By Michael S. Palmer | 2026-04-22 10:08:58


VIEW MORE
story-6
2027 Corvette vs The World: Every C8 vs Its Closest Competitor

Slideshow: 2027 Corvette lineup vs the world.

By Joe Kucinski | 2026-04-24 16:12:42


VIEW MORE
story-7
10 Most Common Corvette Problems of the Last 20 Years!

Slideshow: 10 major Corvette problems from the last 20 years.

By Joe Kucinski | 2026-04-14 16:37:05


VIEW MORE
story-8
5 MOST and 5 LEAST Popular Corvette Model Years in History!

Slideshow: 5 most and least popular Corvette model years.

By Joe Kucinski | 2026-04-08 13:25:01


VIEW MORE
story-9
2027 Corvette Buyer's Guide: Everything You Need to Know!

Slideshow: 2027 Corvette buyer's guide

By Joe Kucinski | 2026-04-17 16:41:08


VIEW MORE