One_96TR4

I'm not really sure what the deal is, but it's never worked. I bought the truck last summer and the rear heat doesn''t seem to work. The fan comes on and blows cold. The front heater blows as hot as ever but the rear won't get hot for the life of me. What might be the problem here. It's not a HUGE deal but it would be nice to have the rear heat working. I always have my rear passenger complaining that it's cold in the back but I turn the heat off or down because I'm roasting. Anyone have any idea's? FYI I'm searched already and just got threads talking about the rear working fine but the front being the problem or adding rear heat etc. etc.

Adam F

Either the rear heater core or line going to it is clogged, or someone before you has blocked it off.

First I'd get under the truck and inspect the lines going into it. Then I would disconnect them and flush the core with the garden hose.

Bigblock

Mine did this one time.I forgot to turn the hot/cold lever to hot!LOL.2nd gen 4Runner.

One_96TR4

LOL..Yeah I managed to remember to do that much. I'll have to check out the lines going to it and see how they look. If I pull the lines all I have to do is put a hose on it and it should come out the other side correct. Would sending air through the core be a better idea?

One_96TR4

Ok well I seem to have found part of my problem. After reading through a bunch of threads about the front heater troubles I found where the lines run to the rear heater. I popped my hood to check them out and to my surprise the lines running the rear aren't hooked up. I was going to hook them back up but I don't know what to re-connect and where. Can anyone tell me what I might need to connect these back and which lines connects to what? Also seeing that these lines must have been disconnected by the PO it makes me wonder why. I think there may be a possiblity that they were leaking otherwise what would be the motivation to bypass them. I'll have the check them out before I reconnect them. Anyone have any idea's as per how the check them for leaks. I was thinking maybe to just hook them up and see if it leaks anywhere.

One_96TR4

Ok I found out what goes where and I hooked the lines back up properly. Haven't noticed any leaks and the rear heat WORKS . I'll be keeping an eye on it for the next few days and make sure it doesn't leak, but so far all seems well. Thanks for all your help guys.

gpcollen1

I would think that something had to be leaking for that to be changed. Keep a looking...

Adam F

Yea, the only reason someone would disconnect the lines is if the heater core was leaking.

Buy or rent a pressure tester and pressurize the system up to 15 pounds. Let it sit for 10-15 minutes and see if there is any pressure loss.

Adam F

I love it when I'm right

MTL_4runner

You and me both.

http://www.ultimateyota.com/index.ph...6&topic=3347.0

One_96TR4

Still haven't seen any leaks. I'll keep looking out and see what I come up with. I'll have to look into the pressure tester but I'm a little busy these days so it'll have to wait until after christmas.

One_96TR4

Well it's been awhile since I reconnect the rear lines and have had my rear heat working. As some may have already read my car was vandalized a few days before new years and I just got it back today. On the drive home I noticed that my temp guage was spiking higher than it normally reads. It went almost to the red when I caught and turned on the heat to bring it down. Once the heat was on it managed to stay normal. I stopped and checked my coolant at the gas station and saw that it was low and topped it up. I have reason to believe that this may have something to do with me reconnecting the rear heat lines. I'm not really sure what or where I should start looking. I don't see any noticable leakage. I did notice that for a while the rear heat was blowing cold but seems to be blowing hot again. Only other issues I have with the car at the moment is an exhaust leak upfront before the cat. I think it's right where the collector is and the exhaust bends to come under the truck.