2.5L ('98-'01) garbage 2.5l

[Dirtman]

I've never used any cleaner. Just disconnect and run the hose through it (both directions!). If the heater core is salvageable this has worked for me. Usually it's just running the water through backwards that does it. But if the valve is stuck closed no amount of flushing will work. I usually find them to be stuck open though because open is the natural position.

 

[Mightyfordranger]

Ok I mean the truck sat for awhile too. The guy said like 5-6 months at least. I'll try to use a hose and run through it.

 

[RonD]

You can use warm/hot water with either CLR or vinegar, not both
Fill up the core, let it sits 20min then flush, repeat as you much as you want
Same for radiators
Flush with water when done

Always reverse heater hoses at the firewall every 2 years or so, it will back flush out and larger debris the way it came in, it will make the core last longer.


What kills heater cores, and rads, is not the blockage itself, but the lack of corrosion protection when coolant is no longer flowing past that metal surface, the coolant can only protect the metal it touches
So you get corrosion build up and maybe a rust thru leak

 

[Mightyfordranger]

thanks man I appreciate the help. I'll try vinegar first. Seems less corrosive.

I'm curious though how bad would it be to change the heater core? With the glove box pulled down seems like you can get right there at it?

Although its never that easy. ...pricks

 

[RonD]

Not on 1995 and up, whole dash needs to come back quite a ways to get core out and new core in, it comes out the TOP of the box

Google: 1999 ford ranger heater core removal

Several videos