fannitti

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.

rzldzl

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....

fannitti

Soak with what

rzldzl

with whatever you choose to use,clr or rad flush

ehall

read the label on the CLR jug, especially the materials it should not be used with, then think about the parts in your coolant system

fannitti

I'm just using it in the heater core not the entire cooling system I'll flush it good with water after.

tjwalker

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.

aj2494

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.

toasterknight

It's likely buildup on the inside of the core rather than the core that is floating in your system. You likely didn't flush it well enough after clr.

fannitti

do i push fluid threw the top or bottom of the heater core or it dosnt matter?

Ron& Lisa

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

ehall

garden hose run through one side for a while then run the other, back and forth, break up the junk

aj2494

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.

freegdr

Vinegar...http://www.jalopyjournal.com/forum/t...diator.476654/

aj2494

This would be my approach for a second flush. Vinegar is really good at breaking down alkaline deposits.