Gain extra benefits by becoming a Supporting Member Click here find out how!

Classic Performance Products Nu-Relics Power Windows
American Auto Wire Hellwig Products IncPerformance Rod & Custom
Danchuk Catalog

Username Post: heater core        (Topic#369776)
Posts: 178

Loc: San Francisco Area
Reg: 12-22-07
10-14-22 03:58 PM - Post#2848557    

My 2000 blazer heater core leaks I know it is difficult to replace. Has anyone had any success with stop leak type chemicals? Thanks in advance for your input


Frequent Contributor
Posts: 1776

Loc: Orlando Florida
Reg: 07-09-18
10-14-22 04:58 PM - Post#2848559    
    In response to apix17

Although tempting, stop leak has too many side effects including clogging the cooling system.

The only real solution is to bite the bullet and change the heater core. While I was there, I'd change the evaporator core too.

People fear change because it threatens what they know, or what they claim to know.

Posts: 178

Loc: San Francisco Area
Reg: 12-22-07
10-14-22 05:40 PM - Post#2848560    
    In response to Tony1963

Yes tony that is my concern also I was thinking of isolating the heater core from the rest of the system filling it with a premixed solution of hot water and stop leak. Let it sit over night then flush it. Then hook it up to the system that way the stop leak is isolated to the heater core. I might give it a try, but yes I agree the prudent way would be to change the core.

Senior Member
Posts: 2650

Loc: Spanaway, Wa
Reg: 10-17-04
10-15-22 09:59 PM - Post#2848620    
    In response to apix17

It sounds like a big job, but removing the dash is the best approach. As for the evaporator core, unless your ac isn't working there's no need and a waste of time.

U.S.C.G. "So others may live"

'96 S-10 SS
2021 Blazer Premier

Member #271 Senior Chevytalk Moderator
Posts: 25803
Loc: Austin, TX 78748
Reg: 05-09-00
10-18-22 02:57 AM - Post#2848726    
    In response to SleeperSS

Agreed! When my '96 Jimmy core leaked, we took out the dash. Cleaned out all duct work too.

'83 Silverardo XST - ZZ4 powered
'95 Jimmy SLT (Bought @131,814)
'96 GMC Jimmy LS Ret. @236651 miles
'08 GMC Acadia 3.6L SLE

"6th Year" Platinum Supporting Member
Posts: 437
Age: 75
Loc: Neosho, MO.
Reg: 04-01-18
10-25-22 07:38 AM - Post#2849029    
    In response to gchemist

I used some stuff, in a blue bottle, it was about $35. Don't remember the name, but it did the impossible job, of sealing a North Star Caddy. Drove the car 6,000 miles then sold it. Told the people it had stop leak in it, and they are still driving it. another thing to check, on GM heater cores, look to see if it has the plastic adapters, from the core to the hoses. I have had two later GMs with cracked adapters.

1952 Styleline Sedan, 62-235, Drum brakes, Manual steering, 2" Drop, 8-60 AC, Glass packs, Two Carbs, and a Cast Iron PowerGlide-
Way out behind the Old School

Half a Dozen in a Row, all it needs for Her to go.


Icon Legend Permissions Topic Options
Report Post

Quote Post

Quick Reply

Print Topic

Email Topic

FusionBB™ Version 2.1
©2003-2006 InteractivePHP, Inc.
Execution time: 0.123 seconds.   Total Queries: 17   Zlib Compression is on.
All times are (GMT -0800) Pacific. Current time is 03:55 AM