From: csr684@NOTyahoo.com   
      
   pedro1492@lycos.com wrote:   
   > A friend put in stop leak and now the heater core is blocked. Unfortunately   
   > it is much harder to replace than radiator or thermostat (which seem to be   
   > okay anyway). He put some detergent in the coolant and reversed the hoses,   
   > which achieved nothing. Look through other forums, I see various ideas:   
   > 1) put vinegar or tartaric acid into radiator, warm up engine then rev it to   
   > 4000 RPM. Then quickly flush system with water and refill with correct   
   coolant.   
   > 2) disconnect heater hoses, and pump gasoline into it. Then flush heater with   
   > water.   
   >   
   > I gather that trying to blow it out with compressed air is bad, as this may   
   > dry out the stop leak, making it worse.   
   >   
   > Has anybody succeeded with clearing a clogged heater?   
      
   About the only way I have gotten any success with a core clogged with   
   stop leak was to use a flush gun and blast it in reverse, even then it   
   wasn't a big success but the core did provide some heat.   
   The one I have uses shop air and water to generate pulses of pressurized   
   water to break up crud and flush it out. It's a twin to the OTC 6043   
   but I've had it for a long time..   
      
   You might be able to contact the company that made the stuff and see if   
   they have any ideas. There are a lot of different formulations out there   
   and knowing which was used might give a better idea of what will work.   
      
   --   
   Steve W.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)