Radiator Flush questions

[bakerhillpins]

All,

So I suspect that I have done this in the wrong order but none the less this is where I am. I have a bit of an overheating issue and I have just been dealing with it. When temps get into the 90s (not frequent here in NH) I have problems in slow/stop and go traffic (again not to common in the woods where I live). But in the interest of getting the car running well enough to make Carlisle next year I pulled the rad to get it cleaned out. Once I got it out and saw that the lower inner was banged up a bit I opted to just have the thing re-cored for $500 rather than burning $90 on the boil as a "lets see what happens".

So now I have a shiny new rad and I realized I should probably flush the system before I put it in and proceed to ruin my investment. Searches seem to discuss running the engine combined with a few fill and drain cycles. Since I don't really want to put the new rad in right away I was looking for feedback on options and how tos.

I was thinking I could pull the thermostat and push water from a hose through the block and out? Or even buy some vinyl tubing and just bypass the rad completely for the flush ops. Should I run a flush agent through the system? I read that CLR (as seen on TV) or vinegar work as cleaners?

Oh, and I am mid stream on a carb rebuild so I can't really run the engine yet. Oh, and my heater controls don't work. Do I need to turn on the heater??? I thought it always passed coolant through the heater core and the controls only control the air flow?

Thanks.

[ODZKing]

I would be interested in this thread as I would like to do a clean-out myself. Not as easy as going to the chinees restaurant ... if you know what I mean.   
I did have several people tell me this: if you flush the system the wrong direction through the heater core, and the core is old, possibly on it last breath - going the wrong way will end it. Not sure how much truth in it but that is what I'd heard.   

[ws23rt]

I would be interested in this thread as I would like to do a clean-out myself. Not as easy as going to the chinees restaurant ... if you know what I mean.   
I did have several people tell me this: if you flush the system the wrong direction through the heater core, and the core is old, possibly on it last breath - going the wrong way will end it. Not sure how much truth in it but that is what I'd heard.   

I  remember hearing the same thing  somewhere.  So my thinking is what possible problem could come from a back flow? All I can come up with is a possible loosening of crud that could block some small passages in the core.
If that disturbance is enough to cause significant blockage or leaking than the heater core can fail at any time anyway. It would be good to find this out at home rather than on the road.
My further thinking on this is that the reason for flushing to begin with is to remove as much crud as possible and it feels like a back flow would do a better job.
I would however try to flush the heater core by itself and not subject it to the possible core blocking crud from the engine.

[cudaken]

 What happens when you flush / hot tank a radiator is you wash out calcium and crude that is acting like stop leak. I owned a radiator company at one point in my life.

When we hot tanked we would pressure test the radiator in water and would sometime see fine streams of bubbles. We called them smokers. if there was only 5 or 6, we would solder them up at no cost.

Far as why back flushing causing a problem, I don't see why?  Maybe because it gets more crap and and exposes the fine holes there where filled with crud?

Cuda Ken 

[cdr]

http://www.evaporust.com/evaporustcsc.html

great stuff

[ws23rt]

What happens when you flush / hot tank a radiator is you wash out calcium and crude that is acting like stop leak. I owned a radiator company at one point in my life.

When we hot tanked we would pressure test the radiator in water and would sometime see fine streams of bubbles. We called them smokers. if there was only 5 or 6, we would solder them up at no cost.

Far as why back flushing causing a problem, I don't see why?  Maybe because it gets more crap and and exposes the fine holes there where filled with crud?

Cuda Ken 

Glad to hear from someone that was in the business. I suspect back flushing as being trouble is a myth that grew from a few problems that were misdiagnosed and word of mouth made them seem real.
The late 60s--early 80s were a time of "high" myth generation.

[Bobs69]

I used vinegar on mine and wow.  I had a hard time getting the antifreeze to stay green after that. 

[bakerhillpins]

If that disturbance is enough to cause significant blockage or leaking than the heater core can fail at any time anyway. It would be good to find this out at home rather than on the road.

I'm with you on that. I have to pull the heater box this fall anyhow to rebuild it.

[bakerhillpins]

I used vinegar on mine and wow.  I had a hard time getting the antifreeze to stay green after that. 

Wow, like BAD I take it?  Could you elaborate on what you did and how long the resolution took?

[Dino]

Bryan make sure you remove the plugs on the engine block.  It's probably all crud in there so you may have to poke it to get the coolant out. 

I thought about cleaning minee by having the engine running and sticking a hose in the top but before I did I figured it wouldn't hurt to put the garden hose in the top hose of the rad and guided the bottom hose into a container.  I let the water run untill the container was full an dby that time it was already nice and clear.  Give it a shot and see what comes out.

Your heating issue is very strange.  My 440 is a little hotter than yours and I can't get it over 180, not even stucm in traffic on a 90+ day.  Have you tried another water pump?

[bakerhillpins]

Dirk,

Are you talking about the freeze plugs??  If not what where are they?    (yes being too lazy to look in FSM now). I already had the Rad re-cored so it's done, clean, new and the fins are not all bent to heck.

When I drained the Rad before I pulled it the antifreeze came out all nice and clean. Then I pulled the Rad out and tipped it upside down to get the last of the coolant out and it looked like Hershey's Syrup. 

It's a stock pump and a clutched fan. The fan looks to be new as it's all shiny. I picked up a new fan shroud at Carlisle as the old was "missing" on the top arch. I can pull the pump but I don't see any reason to change per the sticky thread at the top of this section.

[Dino]

Dirk,

Are you talking about the freeze plugs??  If not what where are they?    (yes being too lazy to look in FSM now). I already had the Rad re-cored so it's done, clean, new and the fins are not all bent to heck.

When I drained the Rad before I pulled it the antifreeze came out all nice and clean. Then I pulled the Rad out and tipped it upside down to get the last of the coolant out and it looked like Hershey's Syrup. 

It's a stock pump and a clutched fan. The fan looks to be new as it's all shiny. I picked up a new fan shroud at Carlisle as the old was "missing" on the top arch. I can pull the pump but I don't see any reason to change per the sticky thread at the top of this section.

Yes freeze plugs!  I hadn't had much coffee yet.   

Stock pump should work fine but I would still remove it to check it out.  Also replace the $5 thermostat while you're doing so.  You have the good pump but for all we know the pump is damaged.

How long does it take for your engine to get up to normal operating temps?  Around the 180 mark?  Mine takes about 10 minutes of crusing betwen 35 - 60.

[bakerhillpins]

Ok, ill need to order/pickup the gasket for it then.  The thermostat seems to work just fine. When not in traffic I get a nice steady 180 (indicated anyhow) temp so I figured it's a capacity not thermostat issue.

Ill admit that I never really paid attention to initial warmup. It was only in traffic that I was watching anything. I would say that it heats up rather slowly (your quoted values seem reasonable) but it's not all that hot in the woods. 

[Dino]

Seems to me the temps are fine as long as you're moving but not when you're stopped.  I want to say the fan/clutch is the issue here.  Either it's not kicking in when it's supposed to or the fan is not sufficient.  I thought you had the stock fan?  Is your timing set properly by the way?  One or two people have been telling me lately that may be an important thing to do.   

Also, are you reading temp off of the stock gauge?  Any chance you can borrow a more reliable one for testing purposes?  For all we know the car is fine but the gauge is telling you lies.  Wouldn't be the first.

[bakerhillpins]

No, I can take stop and go traffic at cooler temps and it seems to idle just fine in the driveway without overheating.  The fan spins, but I don't have any way to quantify "sufficient" from a cooling perspective. According to the FSM I do have a stock setup for a 69 440 AC Auto car. Though it wouldn't be the first time I read it incorrectly.

I also have a bit of heat soak. Which I always assumed was caused because the cars capacity to cool is being stressed.  Forgot to mention that. 

The timing should be set properly. I paid for that service when I first got the car. I will be checking all this when I get the carb fiasco completed and pick up a light.

Yes, temps off the stock gauge. Which is steady most cases but climbs in hot weather and slow traffic.

[440]

I've never had a problem with back flushing a system. The only time you can run into trouble is by using too much pressure, you definately want to turn the heater on as to flush it as well. I wouldn't use a cleaning agent unless you know there is a bit of gunk in the system. Be prepared for leaks as the crap in there could be sealing small holes.

[Bobs69]

I used vinegar on mine and wow.  I had a hard time getting the antifreeze to stay green after that. 

Wow, like BAD I take it?  Could you elaborate on what you did and how long the resolution took?

I just kept changing and flushing with straight water.  Then a couple of flushes with antifreeze. 

A mechanic told me I could have used a "dye pack."

[tan top]

, any cooling system i do , i always reverse flush the heater core with a hose till it runs clear  as a separate unit ,  then by pass it , carry on what ever way your doing the motor ,  when finished with the motor getting it as good as you can  , then  connect  heater core back up

[ws23rt]

, any cooling system i do , i always reverse flush the heater core with a hose till it runs clear  as a separate unit ,  then by pass it , carry on what ever way your doing the motor ,  when finished with the motor getting it as good as you can  , then  connect  heater core back up

I agree   It would be best to flush the heater core by itself. The engine block can have large pieces of crud and they could block some small passages in the heater core.
If I was flushing the engine I would not push that flow through the radiator. The same for the heater core.

[tan top]

, any cooling system i do , i always reverse flush the heater core with a hose till it runs clear  as a separate unit ,  then by pass it , carry on what ever way your doing the motor ,  when finished with the motor getting it as good as you can  , then  connect  heater core back up

I agree  It would be best to flush the heater core by itself. The engine block can have large pieces of crud and they could block some small passages in the heater core.
If I was flushing the engine I would not push that flow through the radiator. The same for the heater core.

 true

[Cooter]

Gentlemen, once a cooling system gets that brown, Muddy, all but solid River bottom sh*t in it, there's no amount of flushing that will help that engine. As soon as you shut down the engine and it cools, that mud begins to collect at the bottoms of the cooling jackets, Radiators tank, heater core, etc. See, once coolant is left in a system for say 8-10 years, and you send an electrical current through it enough times (Remember that badass MSD ignition you have? Where do you think the ground for it is?), it breaks the coolant down to an acid base and it begins to eat EVERYTHING. Yes, and old heater core/radiator. intake gasket[Small blocks only]/etc. will begin to leak if you clean it all out as many times, that sh*t in there is the only thing holding the cooling system together.


Flushing a cooling system after some dumbass has let it turn to mud is like smoking cigs for 35 years, and THEN trying to get healthy by running a marathon.


Too little, too late.

I have had engine blocks HOT TANKED and had to still use a 2500 PSI pressure washer aimed DIRECTLY at the coolant jackets in order to blast that crap out....
No water hose, flush in can, etc. will EVER do what 2500 PSI will.

[tan top]

Gentlemen, once a cooling system gets that brown, Muddy, all but solid River bottom sh*t in it, there's no amount of flushing that will help that engine. As soon as you shut down the engine and it cools, that mud begins to collect at the bottoms of the cooling jackets, Radiators tank, heater core, etc. See, once coolant is left in a system for say 8-10 years, and you send an electrical current through it enough times (Remember that badass MSD ignition you have? Where do you think the ground for it is?), it breaks the coolant down to an acid base and it begins to eat EVERYTHING. Yes, and old heater core/radiator. intake gasket[Small blocks only]/etc. will begin to leak if you clean it all out as many times, that sh*t in there is the only thing holding the cooling system together.


Flushing a cooling system after some dumbass has let it turn to mud is like smoking cigs for 35 years, and THEN trying to get healthy by running a marathon.


Too little, too late.

I have had engine blocks HOT TANKED and had to still use a 2500 PSI pressure washer aimed DIRECTLY at the coolant jackets in order to blast that crap out....
No water hose, flush in can, etc. will EVER do what 2500 PSI will.

thats true too !!

[Brightyellow69rtse]

go with a high flow thermostat too. if your going to replace the pump go high flow for sure 

[ws23rt]

Gentlemen, once a cooling system gets that brown, Muddy, all but solid River bottom sh*t in it, there's no amount of flushing that will help that engine. As soon as you shut down the engine and it cools, that mud begins to collect at the bottoms of the cooling jackets, Radiators tank, heater core, etc. See, once coolant is left in a system for say 8-10 years, and you send an electrical current through it enough times (Remember that badass MSD ignition you have? Where do you think the ground for it is?), it breaks the coolant down to an acid base and it begins to eat EVERYTHING. Yes, and old heater core/radiator. intake gasket[Small blocks only]/etc. will begin to leak if you clean it all out as many times, that sh*t in there is the only thing holding the cooling system together.


Flushing a cooling system after some dumbass has let it turn to mud is like smoking cigs for 35 years, and THEN trying to get healthy by running a marathon.


Too little, too late.

I have had engine blocks HOT TANKED and had to still use a 2500 PSI pressure washer aimed DIRECTLY at the coolant jackets in order to blast that crap out....
No water hose, flush in can, etc. will EVER do what 2500 PSI will.

I agree with you on this also. What we can see in the engine when the freeze plugs are out is depressing. Cleaning as best we can at that point only gets to what the water jet can see. We know there is much left untouched by the pressure cleaning and little can be done for that.
It is true that at home flushing is at best removing what is floating around already. If one was anal about this a colon scope would show more about what we can do little about.  
For the bulk of us at home maintenance types a flush is good when the coolant looks muddy.
As far as adding some chemical to break up stuff we can't see and don't have a problem with in the first place. It seems like asking for trouble.
Out of sight--out of mind---No over heating problem?---move on.

[bakerhillpins]

Dug through some of the FSM last night and they suggest flushing the heater core separate from the block and the block separate from the radiator itself. So that means that getting the rad fixed up first wasn't an issue.

Also suggests to reverse flush the core and block.  Couldn't find anything that specificaly stated that the heater needs to be on though. I suppose it will be obvious if water doesn't flow.

I'm flushing since the rad is new. I don't think the block has been treated that bad cooter.  

[bakerhillpins]

go with a high flow thermostat too. if your going to replace the pump go high flow for sure 

Yea was thinking of picking that up when I get a pump gasket so I can take a look at the impeller at the same time.

[bakerhillpins]

Got a high flow thermostat to go in. Flushed the block with a hose, what ever that will buy me. I can't get the heater core to flush. I got a little trickle of water to flow through but nothing more. I suspect that the valve is frozen up. Tried moving the temp setting back and forth several times but that didn't help.

I did notice that the FSM shows 2 different flow directions?  AC vs non.  Anyone know for sure? I wouldn't have thought that flow direction would reverse just because of AC??  Maybe I flushed the wrong direction?

[will]

I don't thik you have to pop the freeZe plugs out. I drained my block by removing the 1/4" plugs from the sides, green water came out, try this before the hammer and screwdriver method.

[bakerhillpins]

Can you give me a rough idea of where these 1/4" plugs are on the block?  

[bakerhillpins]

After buying 2 of the pump gaskets rather than one and a thermostat gasket and taking the Rad to the shop with the cap, which wasn't returned it's all done. I was outside with a shop light till 10pm on Wed night getting the dam Rad back in the car. 

I found the drain plugs and tried several different moves I picked up playing Twister when I was young but couldn't get them out so I just left left the flush water in the block, put the thing back together, and put in new fresh coolant. She circulates and held at 180. So it's cruising time again. Woot~!~

The plugs on my block are 1/4" allen head and were under the manifold at the front of the block on the passenger side, and center on the drivers.

I put on my a new fan shroud and the milodan thermostat and am running with my freshly rebuilt carb. 

The Heater core wouldn't flush but I suspect that's because the valve is gummed closed. I just jumped out the heater/AC box for now since I will be pulling that this fall before storage for a rebuild over the winter.