Posting for a buddy's '88 4Runner.
Tried burping the system of air with truck pointing
up on incline, removed heater return hose couple times, tried backflushing with garden hose, rear heater works fine, head gasket fine.
Floor trap has warm air, defrost lukewarm at best,
rear heater piping hot!
What gives?
Thanks!
Hugh

I had this problem in my turbo truck. As it turns out, the PO was dumping Bars leaks in it regularly atempting to fix a crack on the top rad tank. All that did was clog the heater core. I first tried the garden hose and found that the core was severely cloged and flowed very little. Some stuff that looked like urathane sealant came out. So I filled the core and the return hose up w/water and put some compresed air to it(be sure to use low pressure). That did the trick. Tons of stuff flowed out. Heater works great now. Good luck. <img src="/forums/images/graemlins/cheers.gif" alt="" />

check the linkage to the controls and at the Box.
on my 85 the cable fell of the air damper and it was stuck on warm. or check to make sure the water valve on the firewall is not stuck...............Karl

Thanks Guys! I'll try / look it over next weekend.
Hugh