Heater core question...general

[Mark_88]

I was just reading another thread about flushing/filling the cooling system and a thought passed quickly through my head...but not fast enough to get out without stirring up my tongue...or my curiosity.

On my 2.3 I usually treated the inlet on the heater core as the one closest to the passenger side fender and the outlet as the other one. And I've read about back flushing the core by forcing water into the outlet so that it washes out anythi8ng that may be built up on the inside of the core...

So far...so good...

So...knowing how most things in the world are or can be reversed...would it hurt, other than having the hoses on the wrong way for routing...to simply reverse these hoses every year or so to try to prevent buildup of crud on the inner heater core?

I couldn't really think of any reason why this wouldn't work...as long as they are connected it should work with the flow in either direction...

Yes? No?

I'd hate to think I wasted all those years of being anal about what hose connected where...sort of like the compression stroke being left or right threaded...(just kidding).

 

[RonD]

Yes, that would work but..............
Back flushing heater core, or radiator, is done to push out any debris that was large enough to get stuck in a passage/tube.
reversing the hoses would indeed push something like that out, but it would still be in the cooling system, hopefully it would settle out in the block.............but could just plug up something else.

If you look at the heater core as a "filter" and back flushing is cleaning the "filter" then it makes more sense to just push out any debris to a bucket or the ground than to recirculate it.

 

[kimcrwbr1]

Another good thing to do is disconnect the heater core and add two short hoses add bleach to one until the bleach runs out thew other and then let the bleach soak overnight. Then adapt the garden hose and flush it both ways good with high pressure water. It works good on the radiator also. Easy off oven cleaner works best just be careful where you dump it out. If the radiator or heater core end up leaking they were bad to begin with.

 

[enjr44]

Don''t think I would use oven cleaner. I once cleaned a coffee pot in a remote location in the Aleutian Islands with oven cleaner. That sucker was so dirty that you could not see the insides of the thing. That pot sprung so many leaks it was unusable. Want to talk about hell to pay, it took almost two weeks to get a new one from the mainland.

 

[lil_Blue_Ford]

I didn't realize there was an inlet and outlet on the heater cores.... since it wasn't marked, I just plugged the hoses on it....

 

[alwaysFlOoReD]

I didn't realize there was an inlet and outlet on the heater cores.... since it wasn't marked, I just plugged the hoses on it....

I don't believe it matters....so I do the same as you.

 

[RonD]

I didn't realize there was an inlet and outlet on the heater cores.... since it wasn't marked, I just plugged the hoses on it....

There isn't an IN or OUT on the heater core, it is just a straight thru passage, no valves or other obstructions to dictate flow direction.
So hoses can be hooked up as you wish.

But after running the core for several years debris can block some of the smaller tubes in the core.
This debris would come in with the flow FROM the engine.
Back flushing is meant to reverse this flow to push out any of this debris.

Hence Mark_88's question about reversing the heater hoses every few years to push out any debris.
You can do this because there is no IN or OUT designation for the heater core.

When back flushing you do need to find out current Flow from engine so you can reverse it.
After engine has warmed up, and you have turned on the heat, you feel each heater hose at the firewall, the warmer hose is the IN from engine, cooler one the OUT.
You can also feel if core is plugged up by the temperature difference, if OUT is much much cooler than IN, then flow is very slow, blockage would be indicated.

To back flush you would send water in thru the OUT connection, pushing any debris out the way it came in, from the IN flow.

I have used CLR and hot water to fill the heater core, let it sit for 20min then flush, repeat a few times to get better flow thru core.

 

[85_Ranger4x4]

Some do have a restriction. One core I had on my Ranger had a restrictor in one side so it wouldn't overpressurize the core at sustained higher RPM. If you hooked it up backwards it would make it more pressure yet than reduce it.

I wish I would have kept that little reducer, I didn't know what it was until I had thrown the core away.