Heater core flush

Messages
2,205
Location
california
Before last winter, I flushed/ backflushed my heater core, twice, just using hose water and pressure, and was able to significantly improve the heat levels exiting the vents, but not to previous levels. Not all that much crud was in the bucket catching the exhaust, and not much improvement was expected so i was pleasantly surprised when the thermocouple registered 25f more degrees at the vents.

In this flush process I had to slightly shorten one of the hoses, a red /all purpose fluid Napa hose replaced in distant past.

This hose is now bothersome, and I am going to replace it, and the rest of the heater hoses that are showing their significant age.

No better time to flush the heater core again, but wonder about using something to perhaps better dissolve/loosen anything occluding the tubes of the heater core. Rest of the cooling system is healthy enough, I drop and replace 2 gallons of the total 4 gallon cooling system capacity, with regular green coolant once a year(ish)

That time is soon, and If I can get more heat from the heater core come this winter, it would be appreciated.
I will check the blend door's seal at some later date.

Any product/method advice?

I have been using a low dosage ( 1 tab) of the ginger root bars leak tabs to prevent the all aluminum radiator from weeping where tubes meet bottom tank, since 2011.
I will continue to do so once I get system refilled after replacing heater hoses.
 
Messages
5,162
Location
Ohio
If it flows freely when you flush it, you do not need any further action or chemicals. I don't understand why you would be putting tablets in the cooling system as a preventive measure if you had no leaks to begin with.
 

wrcsixeight

Thread starter
Messages
2,205
Location
california
I do have a leak at the base of the all aluminum radiator where tubes meet bottom tank. When I drop and replace ~2 gallons, and do not add another tab, it starts weeping there again within a couple hundred miles.

It has done this each year for the last 8 years. I only added the tab once the weeping restarts, after foolishly hoping it will not, each year.
 
Messages
110
Location
Maryland
I do have a leak at the base of the all aluminum radiator where tubes meet bottom tank. When I drop and replace ~2 gallons, and do not add another tab, it starts weeping there again within a couple hundred miles.

It has done this each year for the last 8 years. I only added the tab once the weeping restarts, after foolishly hoping it will not, each year.

I would just get a new radiator, I would not want those tablets in my cooling system.
 
  • Like
Reactions: JC1
I do have a leak at the base of the all aluminum radiator where tubes meet bottom tank. When I drop and replace ~2 gallons, and do not add another tab, it starts weeping there again within a couple hundred miles.

It has done this each year for the last 8 years. I only added the tab once the weeping restarts, after foolishly hoping it will not, each year.

I don't know how you can sleep at night or feel safe driving this car. You need a new radiator.
 

wrcsixeight

Thread starter
Messages
2,205
Location
california
Relax, It weeps maybe a half cup's worth in 200 miles, never reached the asphalt, and has never increased beyond this amount.

A single gingerroot tab stops it( 6 are the recommended dose) and the weep only slowly restarts a few hundred miles after I change 50% of the volume of coolant.

If one tab was not enough or the amount increases, I will radiator shop, until then, not gonna happen.
 
Messages
5,162
Location
Ohio
Relax, It weeps maybe a half cup's worth in 200 miles, never reached the asphalt, and has never increased beyond this amount.

A single gingerroot tab stops it( 6 are the recommended dose) and the weep only slowly restarts a few hundred miles after I change 50% of the volume of coolant.

If one tab was not enough or the amount increases, I will radiator shop, until then, not gonna happen.
They all start as small leaks, atleast pack your Reebok's in the trunk, you may need them.
 
Last edited:
Messages
5,040
Location
Pittsburgh,PA U.S.A.
Breathing in the vapors from the antifreeze is not healthy. I would fix it with a new radiator and what ever else it needed just so I did not have to breath in any of the vapors that might reach into the cabin of the vehicle from the antifreeze getting on anything hot. Your health is much more valuable than the cost to fix it right.

I am not the only one who will not put up with even a small amount of antifreeze smell getting into the vehicle. There was a post on BITOG where someone said that they were getting a smell of antifreeze and the dealer could not find anything to fix so he got rid of the vehicle.
 

BlueOvalFitter

Site Donor 2021
Messages
9,434
Location
Cajun Country, La.
On my F-150 the Ford Flat Rate pays 9.25 hours to R&R my heater core. The manual reads to remove the whole dash. I have seen Ford techs do this job in 3 hours or less and get paid the 9.25 FR. This is a double edge sword for FR techs.
 
Messages
1,139
Location
Pacific Northwest
After flushing the heater core, you could mix up some citric acid based radiator cleaner in a gallon of water, pour it into the heater core and plug the hoses and let it soak in there.. This won't be as effective as having it circulate through it hot, but it might help some.
 
Messages
5,162
Location
Ohio
On my F-150 the Ford Flat Rate pays 9.25 hours to R&R my heater core. The manual reads to remove the whole dash. I have seen Ford techs do this job in 3 hours or less and get paid the 9.25 FR. This is a double edge sword for FR techs.
With experience, the techs discover shortcuts which do not affect the quality of the job they do. I see nothing wrong with them charging book value and they finish it in a third of the time. That's the benefit of OJT, skinned knuckes and the first few taking a little longer than expected.
 
Messages
2,224
Location
Lyndhurst NJ
If you got decent heat out, I would try reversing the heater core hoses and reversing the flow through the core. Works great on many audi/vw that come through the shop. Maybe consider another flush in a year or so after it loosens the crud up.
 
Messages
15,236
Location
Santa Barbara, CA
With experience, the techs discover shortcuts which do not affect the quality of the job they do. I see nothing wrong with them charging book value and they finish it in a third of the time. That's the benefit of OJT, skinned knuckes and the first few taking a little longer than expected.
As one of the techs puts it, you are paying for my years of experience, not the hours the job takes.
 
Messages
257
Location
Pennsylvania
As one of the techs puts it, you are paying for my years of experience, not the hours the job takes.
Yup, back when we were seeing 94-01 Dodge Rams with evaporator core issues I did so many of them that I could easily do 3 of them in one day. I think one paid 6-7 hrs off the top of my head. You were paying for my experience.
 

wrcsixeight

Thread starter
Messages
2,205
Location
california
My heater core's location, does not require opening up the dash, but I don't really know how hard it is to R&R it where it resides in engine bay. Rather not find out, but checking the blend door's seals condition itself is likely as much or more work.

When I last flushed it before last winter, I had to cut and shorten one heater hose which could not be removed otherwise, which has subsequently led to issues with interference with nearby objects, which is the main reason I want to replace the hoses, in addition to their age and suspect exterior appearance.

While I have the hoses off the heater input and outputs, I was considering putting some potential product into the heater core to help the following flush/backflush possibly remove more occlusions, and get slightly more heat from it afterwards. But will likely not bother now, with the potential occlusion softening product. Perhaps I'll just expend more efforts with the actual flush/back flush lather rinse repeat scenario.

I was intending not to run something in whole cooling system, just into/through the heater core when I had hoses off.

I'll likely just get more than enough new 5/8" ID heater hose, route it with more slack and less intrusion, and flush and back flush existing core before buttoning it up.

Was considering an inline coolant filter on the heater hoses too, but they are not cheap, and add more failure points. Don't know If I'd want to reverse flow direction through core without a filter or a full system flush shortly thereafter, which I do not care to do.


I keep close watch on coolant levels in radiator and expansion tank, well aware of its potential seepage restarting.
I can usually smell it before I notice levels dropping.

No loss in the last 8 K miles and 3 x country road trips, granted, they were in winter, and when I did the heater core flush before last winter I did not wait for it to start seeping, but dissolved a single ginger root tab into the newly added 50/50 at that time.
 
Messages
5,162
Location
Ohio
On my F-150 the Ford Flat Rate pays 9.25 hours to R&R my heater core. The manual reads to remove the whole dash. I have seen Ford techs do this job in 3 hours or less and get paid the 9.25 FR. This is a double edge sword for FR techs.
I don't know when they changed but the older F150's were very easy to change. I recently replaced my core in my 87 in about an hour, right through the glove compartment hole.
 
Messages
3,031
Location
Florida
Why are you flushing the system? If you are using the proper coolant and only distilled water you should have no problem just doing a drain and refill when required.
 
Top