Clr heater core flush
#1
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Clr heater core flush
I'm gonna try clr and flush my header core with it as I have very little heat. I upgraded my coolant system from closed to open system and ditched the heater control valve. I think I have the hose from t-stat to the top of heater core and water pump at the bottom. Dose it hatter how I hook the hoses up when flushing heater core and clr. I'll be using a small electric pump don't feel like using a drill for hours on end with the electric one it will be fine. Plan on flushing it good for like 2 hours or so then flush it real good with water hook it up and hope fire the best that I have heat.
#2
Senior Member
let it soak
then blast it out with air compressor, put water in, blast it out....repeat til comes out clean (no more flakes)
ive done this every fall for the last 5yrs to have heat
i use radiator flush, some think clr will cause issues....
then blast it out with air compressor, put water in, blast it out....repeat til comes out clean (no more flakes)
ive done this every fall for the last 5yrs to have heat
i use radiator flush, some think clr will cause issues....
#3
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#6
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#7
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Year: 1999
Model: Cherokee
Engine: 4.0
I have had some success using CLR on a clogged heater core with some compressed air, but I consider it a "last resort" option, meaning......if it doesn't work, I'm going to replace it anyways. So not much to lose.
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#8
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Year: 2001
Model: Cherokee
Engine: 4.0
WARNING, THIS IS NOT A SCIENTIFIC OBSERVATION AT ALL!
I didn't play around too much with my cooling system before I messed with the heater core, but I cleaned it out with CLR the second time it had to be flushed. I now consistently notice junk in my coolant. Every component in the cooling system is less than a year old, besides the heater core. So I have to assume that the core is breaking up. Whether this was caused by CLR, I don't know. But I do know that it seems like it's breaking down faster than it should. I personally will not be using CLR again.
I didn't play around too much with my cooling system before I messed with the heater core, but I cleaned it out with CLR the second time it had to be flushed. I now consistently notice junk in my coolant. Every component in the cooling system is less than a year old, besides the heater core. So I have to assume that the core is breaking up. Whether this was caused by CLR, I don't know. But I do know that it seems like it's breaking down faster than it should. I personally will not be using CLR again.
#9
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Year: 1999
Model: Cherokee
Engine: 4.0L I6
WARNING, THIS IS NOT A SCIENTIFIC OBSERVATION AT ALL!
I didn't play around too much with my cooling system before I messed with the heater core, but I cleaned it out with CLR the second time it had to be flushed. I now consistently notice junk in my coolant. Every component in the cooling system is less than a year old, besides the heater core. So I have to assume that the core is breaking up. Whether this was caused by CLR, I don't know. But I do know that it seems like it's breaking down faster than it should. I personally will not be using CLR again.
I didn't play around too much with my cooling system before I messed with the heater core, but I cleaned it out with CLR the second time it had to be flushed. I now consistently notice junk in my coolant. Every component in the cooling system is less than a year old, besides the heater core. So I have to assume that the core is breaking up. Whether this was caused by CLR, I don't know. But I do know that it seems like it's breaking down faster than it should. I personally will not be using CLR again.
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Year: 98 & 99 flame Red -01 blue
Model: Cherokee
Engine: 98 -4.6, 99 - 4.0 01-4.0
I did it both ways, You can see the difference in flow going both ways And keep doing it until the flow gets even from side to side.
Plan on doing it a couple times Because for me It took some work and I would loose flow again in about a week, So I keep doing it along with a flush and fill.
Once I got it somewhat better I switched the hoses and ran it backwards after I got a longer return hose and it really broke it up, We have quality heat now -still running backwards through the core.
No clr, I just used the garden hose with a switchable head on it- jet setting worked well
Plan on doing it a couple times Because for me It took some work and I would loose flow again in about a week, So I keep doing it along with a flush and fill.
Once I got it somewhat better I switched the hoses and ran it backwards after I got a longer return hose and it really broke it up, We have quality heat now -still running backwards through the core.
No clr, I just used the garden hose with a switchable head on it- jet setting worked well
Last edited by Ron& Lisa; 02-13-2016 at 05:27 PM. Reason: No clr
#13
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Year: 2001
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I assure you that I did, with air and water. This ain't my first heater core flush. It's also had 2 radiator swaps and a water pump since then, so I've ran a fair amount of coolant through it.
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