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Backflushing a heater core


Dave_s
01-01-2008, 08:26 PM
I need to back flush the heater core on my 97 Taurus. I have a couple of questions:

1) is the line on top (as it goes into the heater core) the in, or is it the one on the bottom?

2) I am having trouble disconnecting the hoses. I'm thinking I can connect a tee (the ones you find in the prestone radiator flush kits) to each side of the heater core. That would give me something to hook the hose up to, and also an easy way to flush it again later. Will this work, or will the coolant go the long way around (through the engine and resevoir) instead of through the core?

Any other advise in getting this done would be appreciated. I figure If I flush it and I don't get my heat back I have to pull the water pump.

tripletdaddy
01-02-2008, 02:59 AM
I need to correct myself here, as I incorrectly stated the order in which the heater core gets its heated water. I should have said typically on an engine, the heater core gets its water from the engine near the thermastat and upper radiator hose, it passes through the core and returns to the engine at the water pump. So trace a heater hose that goes to the front left side of the engine from the fire wall. It becomes a shiny pipe before it connects to the front of the engine. The right hose at the firewall goes to the back side of the engine, connecting next to the thermastat and upper radiator hose. From there, your on your on, but truthfully, they aren't built one way only unless they have a valve on it which most don't have. But I guess you are wanting to know which way to reverse the flow throught it to backflush it?

If that doesn't work and it isn't too expensive for you, a radiator shop should be able clean it for you.

mwt47
01-02-2008, 05:30 AM
Do you not have heat or do you have the Brown Sludge problem?

If you just need to get heat. remove the two hoses going into the Heater Core.

THis kind of tool works well to break the seal.

http://www.etoolcart.com/ProductImages/pictures/CAL736-L.jpg


After you get them off Shove a garden hose in the outlet and run it for a while. The stick it in the other side and do the same thing.

Make sure the problem isn't the blender door.


If you have the Brown sludge/coolant issue post back here and I will write the correct procedure up for you to eliminate it.

Mike
:smokin:

Dave_s
01-02-2008, 07:32 AM
Both. Its got 185K on it so I figure a temporary fix is good enough. I need to start thinking about replacing it in a year or two, so if I can get heat out of the thing I'll be happy.

Colt Hero
01-03-2008, 11:23 AM
I flush my '97 Taurus wagon's heater core every winter because it blocks up every year and I have no heat when the cold air arrives. In the summer time (when it's presumably blocked), the coolant can still flow through the H-shaped (parallel link) bypass hose (Ford's "fix" to make sure a blocked core doesn't build up too much pressure and fail), so that actually works out pretty well because my heater core can't throw off any residual heat into the cabin during the summer.

What I did was make myself a couple of hoses specifically to perform the flush each year. I used two pieces of old remnant garden hose (pulled from the recycling bin at the dump). Make sure they're long enough to drop into your catch basin on the ground (5 or 6' should do it). I chose two separate hoses so that I could have a female coupling at the end of both of them. This way, you can attach both hoses and then repeatedly plug in the male end of your GOOD garden hose to each to flush both ways (for about a minute each time).

As far as connecting them, on the water pump side of the engine, if you look toward the firewall but very high up - not down where the elbow hoses are - there is a hose coupling there that you can remove and plug into. On the thermostat side there is a similar connection (it's a very short elbowed hose, if I remember right). You don't have to make either connection at those firewall elbow hoses - which are hard to get to.

One other thing I did: I inserted tubular brass couplings into the ends of both garden hoses. These are the serated-looking ones that kind of have to be forced/turned in and then are extremely hard to remove because they have teeth like a shark. Then, I slipped a 6" piece of standard black rubber hose onto the other end of the coupling so that the end result was I had a garden hose remnant with a female coupling on one end and a 6" piece of rubber hose coupled to the other end (this makes the connection to the car easier and more natural). Everything is coupled together with hose clamps. I even leave a hose clamp on the end of one (or both of them) at all times (for connections purposes), and I replaced the clamps on the hoses in the car (that I de-couple) with screw-type hose clamps to remind me where I need to make my connections each year (because it's easy to forget).

Ford should've passed out these hoses when they added the H-shaped bypass hose. The bypass hose doesn't do anything to keep the heater core from getting plugged up!

mwt47
01-03-2008, 04:51 PM
Or you could just unplug both sides of the heater hoses and stick a garden hose in it to flush the heater core.

There is a way to eliminate the brown coolant altogether .
Mike
:smokin:

Dave_s
01-03-2008, 07:03 PM
I would like to know how to get rid of the brown coolant. Please let us know what your suggested procedure is.

mwt47
01-03-2008, 07:21 PM
This is basically what the TSB from ford originally wrote.

Ford still lists a kit that adds the bypass hose to keep coolant circulating thru the heater core all year round but good luck finding it from Ford.

You can get it off a salvage 99 model or newer.
or make your own

Anyway

Drain the your radiator.

Leave the petcock open.

Pull the thermostat out and reinstall the housing.

Pull the degasser tank out

The big hose that is in the front will accept a garden hose.
The small hose that runs over to the top of the degasser tank needs to be pointed over the fender

Turn the waterhose on and run it while the engine is running and the water pump is spinning.

after everything finally runs clear

Unhook the hoses to the heater core and flush it both ways.

Change the water pump

Add a grounding strap from the heater core to the Water pump
Ford did this in 99 so 99's should have it.

Put everything back together including the T stat

Run Prestone Super Radiator Cleaner for 3 to 6 hours of drive time.

This can be done over several days if necessary.

Go back and completely flush the system again.

If you had a super bad case of Brown Sludge you can run another treatment of the cleaner.

Then add the proper amount of coolant.

Installing the Bypass hose, New water pump and adding the ground strap is critical to ensure that the brown coolant doesn't come back.

The Vulcan is the only engine that gets this. The Duratec doesnt.

A lot of overheating problems are caused by the impellers on the water pump being eaten away.

As previously stated. Ford knew about this and finally came up with a kit to correct the problem. They don't offer it anymore and I can't remember what the TSB that lists the kit number is. You can call Ford and they can look it up if you find a parts guy that gives a *hit



Mike
:smokin:

Dave_s
01-03-2008, 09:09 PM
Sounds like a case of beer instead of a six pack. What does the grounding strap do? If don't replace the water pump, what happens? Does it come back, or are you taking a risk that the water pump is bad?

mwt47
01-04-2008, 09:15 PM
Sounds like a case of beer instead of a six pack. What does the grounding strap do? If don't replace the water pump, what happens? Does it come back, or are you taking a risk that the water pump is bad?

From what I have read the Brown sludge is an Electrochemical reaction.

The ground strap supposedly stops electrolysis.

The water pump on a higher mileage vehicle has the impellers corroded and they don't flow a lot of coolant.

The first time I did it to my Vulcan I didn't change the pump out and it came back.

I had to do it again six months later and I changed the pump out that time and it hasn't been back.

Mike
:smokin:

tripletdaddy
01-06-2008, 03:44 AM
Not knowing the best way to handle my own correction, I'm reposting this to be sure it get's out, and if it's a duplicate, my apologees in advance.

I need to correct myself here, as I incorrectly stated the order in which the heater core gets its heated water. I should have said typically on an engine, the heater core gets its water from the engine near the thermastat and upper radiator hose, it passes through the core and returns to the engine at the water pump. So trace a heater hose that goes to the front left side of the engine from the fire wall. It becomes a shiny pipe before it connects to the front of the engine. The right hose at the firewall goes to the back side of the engine, connecting next to the thermastat and upper radiator hose. From there, your on your on, but truthfully, they aren't built one way only unless they have a valve on it which most don't have. But I guess you are wanting to know which way to reverse the flow throught it to backflush it?

If that doesn't work and it isn't too expensive for you, a radiator shop should be able clean it for you.

Colt Hero
01-06-2008, 09:15 AM
I have to wonder if Ford's "kit" really solves the brown coolant problem. I bought my '97 Taurus brand new from the dealer (in January '98) and it already had the "H" bypass hose installed. Presumably, the dealer also did the flush, etc. Still, I had the sludgy coolant problem shortly thereafter (and still do). Back in 2003 timeframe, I ended up buying the special flush liquid used in the TSB (ph Iron Cleaner - 2Qt bottle) for $40 from the dealer to see if that would solve the problem - and it seemed to help - but the problem remains to this day.

Possibly the ground strap wasn't installed? I've never noticed any wires running from the heater core to the water pump. I don't think my car has that. I know the water pump is original. I once pulled the hose at the water pump and was horrified when the goose neck came out with it completely corroded! I ended up buying a short piece of brass tubing and hammering it into the water pump with a socket. It's still there (about 4 years now)...

mwt47
01-06-2008, 09:55 AM
Changing the water pump on a 97 Vulcan takes a little over an hour for the average wrench.

I would change a 10 year old one just to sleep better at night.

Mike
:smokin:

mwt47
01-06-2008, 10:09 AM
On the water pump it is on the top towards the firewall

http://i34.photobucket.com/albums/d132/mwt60/IMG_3509.jpg

mwt47
01-06-2008, 10:10 AM
Here is where it attaches to the heater core

http://i34.photobucket.com/albums/d132/mwt60/IMG_3507.jpg

gotwood2
01-07-2008, 07:10 PM
Like everyone here, I too have a 99 Ford Taurus SE, with a heat problem. I have flushed my coolant system approx 6 times, due to the fact I had the "Brown Sludge from Hell". I finally believe I got it all, water runs clear now. Used commercially made "Flush" once. I replaced thermostat. I am some what lucky that my mother works for Ford in the St Louis area, so I was able to get the Ford only "bypass assembly" Part # F8DZ-18B402-AA ($50 or so). I will be placing that in tomorrow I hope. The question I have, to anybody, is I have no heat, unless it is at 3500 rpm then warm air comes out, I have never had any issues with the car over heating, since this does not happen, is the water pump bad? I have read in other forums that the impellers on the water pump possibly have corroded away, but it would allow enough coolant to flow so it would not let the engine overheat. Is that possible? Not to have fins, but yet still cool!? My next step is to get a new water pump, should I spend the money? Thanks

mwt47
01-07-2008, 08:32 PM
Grab one hose going into the heater core then grab the other one.
One should be a little bit warmer than the other but they should both be warm.

If one of them is cold you have a plugged heater core.

Pull the hoses off and stick a garden hose in each one of them for a while.

If the core isn't plugged you may have a blend door problem
It may be a mechanical problem with the door itself or a vaccuum leak

If you are still on the original water pump you may not be moving enough coolant

Mike
:smokin:

Colt Hero
01-07-2008, 08:46 PM
mwt47:

Very good - thanks for that picture. Just went outside in the dark and flashed a light under the hood. My '97 GL wagon (150k miles) definitely DOES HAVE that ground strap. That's good to know. Never noticed it because the connection point is directly behind the water pump hose going to the heater core. The strap runs to the firewall just as your picture shows and bolts to a piece of color-coded metal that is welded to (and curves outward from) the firewall. There are also some smaller gauge wires coming from the harness that bolt there too.

SO, I've got the ground strap, the "H-hose" kludge, and I've flushed the system with the ph Iron Cleaner used in the TSB (and Prestone flush and water several other times). Still, the sludge remains. BUT, the original water pump - surely very corroded inside - is still in there. I probably should replace the pump - even though it's not leaking - because it probably isn't circulating the coolant as well as it could be (but then again, I've never had any overheating problems with this car, either - and the T-Stat is also original). Funny thing is - when I pulled that hose off the water pump a few years ago and the corroded neck came out with it, I bought a new pump. Think it was about $35 at Advance Auto. Never installed it, though, because I found that brass replacement neck ($2) that ended up working just fine. Hard to believe a new pump will finally solve the sludge problem, but I probably should change it anyway...

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