Flushing Out a Heater Core

[Snuffy "Hub Cap" McKinney]

Back to the 97 Aerostar again.... It appears that the heater core is nearly plugged. Some heat gets through, but not much.

Heater valve & vacuum work fine. A friend said to pull the valve off and connect a garden hose to the outlet and hit it with some short blasts of from the garden hose. Then connect to the inlet and repeat until it flows free and clean.

But, and this is a big butt, I have done these kind of things before and been sorry later. So I thought I'd ask the online brain center for some (good) advice first. The last thing I want to do is open a leak in the core and hose down the front seat.

[Snuffy "Hub Cap" McKinney]

PS - Forgot to say - the Hot-Cold lever is opening and closing air to the floor, vent or windshield properly.

"Snuffy "Hub Cap" McKinney" wrote in message news: [e-mail]... Back to the 97 Aerostar again.... It appears that the heater core is nearly plugged. Some heat gets through, but not much.

Heater valve & vacuum work fine. A friend said to pull the valve off and connect a garden hose to the outlet and hit it with some short blasts of from the garden hose. Then connect to the inlet and repeat until it flows free and clean.

But, and this is a big butt, I have done these kind of things before and been sorry later. So I thought I'd ask the online brain center for some (good) advice first. The last thing I want to do is open a leak in the core and hose down the front seat.

[Terry Coombs]

Just because there is restricted flow does not mean it's in the core - though it may be . So start off with the hose just cracked on a little , and don't use any clamps so it can blow off at low pressure . I'm having a similar blockage problem with our '99 4Runner , but it's apparently caused by deposits in the water jackets/cooling system that have flaked off . I used some CLR to flush the cooling system after a thorough rinse to remove the A/F , which has helped but not cured the problem . Yours could also be caused by a hose with a degraded lining , a flap blocking the hose - that is often accompanied by a bulged hose .

[Tony Hwang]

Do a chemical flushing proper then. Reverse flush too.

[clare]

Kinda hard to do with the quick-connect hose system Ford uses on the heater cores - - - - No clamps.

[bob haller]

I havehad dodge caravans since 1990. picked up this procedure from a local radiator shop.

its best to notonly flush the heater core but change all the coolant.

flush the heater core with both water and air. pulse the air on and off while putting water thru the core.

it generally lasts a couple years, and while you at it replace the thermostat. it might be stuck open or running the engine cold, so the heater never really gets hot.

never ever!! never ever! use radator stop leak, unlessyou really want to replace the heater core and perhaps even the radiator:(

[Tony Hwang]

Flushing is rocket science? Add chemical flush agent, drive around until engine reaches operating temp. Wait until cools down, reverse flush until clear water comes out. If once is not enough, repeat. Fill with 50-50 compatible coolant. While at it replace rad. cap and thermostat as well. Check serpentine belt too. Periodic routine maintenance is always good idea. Neglect and laziness creates more difficult problems.

[clare]

I'll dissagree on one point. A "proper" rad sealer can be used with almost total safety if the instructions are followed. As an automotive professional I have used numerous "rad sealer" products MANY times over the last 40+ years without any problems.

[clare]

The most important thing is to check and maintain the pH level of the coolant - when replacing the coolant and every year. Too low a pH will corrode the system. Too high a pH will cause scale and plug the system.

Having the coolant filtered and the pH adjusted annually, or every 2 years will prevent almost all cooling system problems except those caused by exterior elements - like salt, rocks, etc.

[Tony Hwang]

I don't hesitate tasting it with my tongue, LOL!

[Stormin Mormon]

I've found that if I leave the ten minute rad flush in for two days, the water pump seals leak. And then I have to replace the water pump.

[Stormin Mormon]

I've found to look up the system capacity. Put in half that volume of pure antifreeze. If you refill with 50%, you end up with about 20% when it mixes with the fluid that stays in the system.

[My 2 Cents]

I did the garden hose thing on a old Mercruy Comet I once had, I let the water run through the core and into a 5 gallon bucket just to see what and how much came out. A lot of rust, actually a whole lot of rust. I suppose that heater core was the low part of the cooling system. I hooked the hoses back up and the heater worked liked new after that. Prestone makes a kit you can cut the hoses and do the same thing which might or not be a good thing. This one is on ebay but the auto parts stores have them.

[clare]

When using ANY automotive chemical it is VERY important to follow the instructions to the letter. Actually not just automotive chemicals.. It is generally unsafe to use any chemicals (or medications) in ways other than those recommended by the manufacturer.

[clare]

Proerly installed and used the "prestone" flushing "T" is a good tool. At the dealership we had a cooling system flushing and coolant recycling machines - which both used the flushing "T" as an access point.

[Stormin Mormon]

Hello, Captain obvious! I wrote to share an experience I had, and save others from making the same mistake. Your reply has all the sound of a condescending superior being who is stating the obvious to the ignorant peasants. Must suck to be surrounded by people who make mistakes, your royal Lordship.

- . Christopher A. Young learn more about Jesus .

. .

[Jon Danniken]

The problem with those kits is that the cap on the fill fitting can weaken or come loose and end up leaking. It's also not recommended to flush the entire system from the heater hose; while heater core flushing is done during a routine flush, it is done seperately from the engine block and radiator.

Personally, I back-flush the block from the thermostat housing (with the hose still on), and the radiator from the bottom hose. I just use a hose gun and pulse the input so I'm not subjecting the system to the full pressure of a typical residential water system.

Jon

[clare]

No , Mr Thinskin. I'm just replying , indirectly, to all the guys on this newsgroup who complain about products like rad sealers plugging their cooling systems, changing transmission fluid damaging their transmissions, etc and claiming automotive chemicals are all useless or worse.

My experience over half a century and more (ouch - that makes me feel OLD!!!!) is there are many good automotive chemical - or as some call them "mechanic in a can" products out there that can really save you a lot of work and money "if used as directed"

I've made my mistakes too, in learning that lesson.

Lesson one - when using a "fast chemical flush" be VERY carefull when you open the rad cap. I had a combination of chemical burns and scalding that would have been a lot worse if I hadn't run into the carwash immediately and hosed myself down - I was 16 and stupid at the time!!

[clare]

The flushing machine does basically the same thing, with regulated pressure being pulsed through the system. Been a long time since I last used one so I forget all the details - and yes, sometimes the caps/"T"s deteriorated with age, but usually only on the cheap "clone" parts. If flushed every 2 years, as was recommended back in the day, any mechanic worthy of the name would catch a deteriorarting "T" and replace it before it caused a problem. Most were good for about 10 years minimum.

[Tekkie®]

[e-mail] posted for all of us...

You mean I should not double up my meth dose when I get a little twitchy?