rear heater (1 Viewer)

[Brasi]

The other day I noticed some type of fluid material around the rear heater. It did not appear to be gasoline. I never use the heater but once or twice recently I turned it on to see if it was functional, which it was. Any idea what it could be? I have attached a pic.

 

[GA Architect]

More than likely the liquid is antifreeze.

 

[Brasi]

Oh got it...that makes sense as it did appear to be that kind of consistency. Does that indicate an issue when it appears in that location or is that within the normal range of events?

 

[1969FJ]

You have a leak..

 

[shawnfj40]

If you pop the top off of it it will be easier to see where the leak is. You might get lucky and it only be the hoses.

 

[GA Architect]

Oh got it...that makes sense as it did appear to be that kind of consistency. Does that indicate an issue when it appears in that location or is that within the normal range of events?

You should not have a leak in that location. It is ether your supply or return line, their connections or the core. Below is an exploded diagram of the piping and rear heater.

 

[Brasi]

Does the top of it just pull off? I don't want to break anything but it looks like it should just pull off

 

[GA Architect]

Does the top of it just pull off? I don't want to break anything but it looks like it should just pull off

Remove the clips and the top comes right off.

(pic gleaned from MUD)

 

[Brasi]

Remove the clips and the top comes right off.

(pic gleaned from MUD)
View attachment 1902174

I got the clips off and the top off. I did not see anything glaring that I could sort out. In the meantime... how dangerous is it to drive with this leak?

 

[RustyRanger]

Don't lick the puddle? Antifreeze is only toxic if you eat it. Keep dogs and kids out of the back until you fix it or cap the lines. You probably have a pinhole leak in the heater core or the hose.

 

[Brasi]

Hahahahha thanks. So I understand the mechanism... does the antifreeze only circulate to the rear heater if I turn on the heater or does it circulate back there are part of the normal flow?

 

[RustyRanger]

Hahahahha thanks. So I understand the mechanism... does the antifreeze only circulate to the rear heater if I turn on the heater or does it circulate back there are part of the normal flow?

I'm not too familiar with the rear heater or late model systems in general but usually the circulation is turned off when you have the heat off/temp set to cold. Early series ones had a manual shutoff on the engine for the heater coolant, might look for that. That damp patch isn't a danger to the engine.

 

[Brasi]

Perfect... I will look for it

 

[GA Architect]

Perfect... I will look for it

Suggestion: Keep the top off the rear heater. Drive the 40 around and warm it up. Once the engine is warm, park the rig. And with it running, pull the "warm pull" switch to circulate the heated antifreeze. DO NOT PULL THE "FAN PULL" SWITCH, IN CASE THE REAR HEATER CORE HAS SHIFTED. Now get in the back and look for what is leaking. Be careful and use gloves, the heater core could be veddddy hotttt.

Since the rear heater is leaking, be sure to check the front as well.