FJ40 Rear Heater Performance

[TL44]

That tells me that the heater core is also clogged up, not allowing hot coolant to flow through the proper way. Both lines should be hot if it is working correctly.

You should flush both front and rear when you do it.

I had the entire front heater box out and I flushed out that core before I reinstalled it. I'll have to take out the rear one and flush.

 

[Rock Slide]

Well, not sure if the gremlins left or what, but both my front and rear heaters now blow air. The air does not get hot, but does get slightly warm. I'll have to take a look at my heater cores next. Just glad to know both heaters moves air.

 

[Cromagnon]

Well, not sure if the gremlins left or what, but both my front and rear heaters now blow air. The air does not get hot, but does get slightly warm. I'll have to take a look at my heater cores next. Just glad to know both heaters moves air.

Check the coolant temp first. If it isn't getting hot then your heater isn't going to blow hot air. Second, check that the hot water valve is working, full open and close. If it is only opening partially then again you aren't going to get hot air. Also if it doesn't close all the way you are going to cook in the summer. Lived in Biloxi and it was hot enough without extra heat from the heater. Then I would check the cores and the exterior fins of the cores. Let us know what you find please.

 

[Helipilot]

Had a similar issue with a '78 and it was the motor needing to be cleaned and lubed as well as the fins hah been mostly blocked with mud and dog hair from the PO. cleaned it all out and it kept me warm in Minnesota during the winter while flying a medivac contract up there. Good luck!

 

[TL44]

UPDATE: I removed my rear heater , there was a nice collection of dirt,dust,animal hair and cigarette cellophane wrappers.I vacuumed & blew all that out, cleaned & flushed the core. The fan motor was spinning pretty freely I put it back together & it blows better (pipes are hot after a while) but nothing like the external ones do. These later model ones under the console must have a smaller fan motor. Now after 3 weeks & hours of running it one of the hoses under the console is leaking,I'm hoping to dive back into it Sunday. Any opinions of those hose clamps with the cotter pin? Can they be replaced with a standard style hose clamp?

 

[Suntreemcanic]

If you have to drain the system to replace a hose remove the core and clean it out. I bought some radiator cleaner mixed it in a 5 gal. bucket and let the core set over night, then cleaned it out with garden hose. Made a big difference in heater performance.

 

[Cromagnon]

The cotter type hose clamps can be removed and reused if disassembled carefully. Scroll about half way down the page for directions here. I have used regular worm screw type clamps with good results as long as there is space. If you have to have the original type of clamp here is one source, Cotter Type Clamp.

 

[TL44]

The cotter type hose clamps can be removed and reused if disassembled carefully. Scroll about half way down the page for directions here. I have used regular worm screw type clamps with good results as long as there is space. If you have to have the original type of clamp here is one source, Cotter Type Clamp.

Thanks a ton!! Yeah space is my issue, I put on a regular worm screw clamp but I can't get the metal shroud/cover/guard that clamps around the lines & clamps to fit. I'm probably going to make another cover to fit for now since the worm screw clamp stopped the leak.

 

[jengel199]

I posted in the wrong thread.