so just thought I would share this with you guys and gals .. although it is not in my Trekker , it can be applied to most any vehicle . but "do' at your own risk .
my /86 DD/shop truck has had no heat for a couple of years now , I just never seem to be able to find the time to put in a new heater core . So with winter approching , and me not looking forward to driving to work shivering every morning , I thought it time to do something . I Have been thinking of the CLR product , thinking it might work . The 86 , like the 79-83 requires the removal of the dash ~ 6 hrs , and with no time , I thought I would try the CLR . It is not recomended for use on copper , but I figered if it didnt work , then i would force myself to then remove the dash and replace the heater core . it worked ..
seperated the hoses at the heater control valve , and using air , pushed out the fluid left in the core . dumped in the CLR and let sit for 1 hr . Then rinsed it all out , re connected the hoses , and filled with coolant .
I dont know if there was any damage caused to the heater core , but my heater now blows hot air again