OK, thought I had a heater core leak a few days ago but from the help from a few people here I realized it was my master cylinder. Found fluid on the drivers side floor mat. OK, now got that fixed and decided to look at the passengers side for the heck of it. Gues what I found. Small amounts of coolant leaking! UNBELIEVEABLE. I really do not think it was leaking before I flushed my radiator last week. Anyway, cant afford to change out the heater core now, so
1. Will this leak when the heat is off, or when the heat setting is not on heat?
2. Can this leak be fixed with Bars Leak?
I really would not want to attempt this myself so I am looking for a short cut to hold me over until I can get some cash together. Thanks in advance

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D Smith
ALABAMA
1970 Chevelle 350

When it rains it pours. It happens to everyone.

TESTIFY!!! I know the feeling!
Well, no this is not a stop leak fix. That will only gum up your radiator and not stop the leak.
One way would be to lose heat in the car and just hook the hoses together on the engine side of the firewall. This will by pass the heater core, but b-r-r-r-r will it be cold inside. I think either a short 1/2 or 3/4 piece of copper tubing and a couple of hose clamps will do the trick.
The other week we decided to have the rear window re-seated in the 70, and the DAY of the appointment...the windshield starts leaking. Oh well...

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Better Late than Never Fred
Team Chevelle #400
Madness takes it's toll, please have exact change.
www.geocities.com/motorcity/shop/9385/1970Chevelle.html (http://www.geocities.com/motorcity/shop/9385/1970Chevelle.html)


[This message has been edited by Riffers70 (edited 10-22-99).]

i remember when i was a kid my oldest sister had a small leak in the radiator on her '69 charger . what she did to get by was to put a little black pepper into it to plug the leak .

OK, so the Bars Leak is out. Will this problem get worse, ie leak more, and more and more? Much thanks.

It does not take much to break the brass core connections if you change the heater hose's or put any strain on them. I had this happend, had the Chevy dealer flush my '70 el camino and install new hose's thermostat etc. 2 days later it was leaking and when I took it apart (major job btw) I found there was a break in the location where the fitting that goes thru the firewall and the core meet. They must have forced the old hose off instead of gently cutting them off. Shows the lack of experience.

The water flows thru the heater core all the time so the leak won't stop. Ever since this happen to me many many years ago I carry a 3/4 inch and 5/8 inch bolt in my tool box. Disconnect the hoses from the heater core, plug them with the bolts and clamp the hoses to the bolts.
The easiest way to get the heater core out is to remove the inner fender. Not real difficult, just takes a couple hours.

Heater cores always go before a radiator since they aren't as thick.

Bill

Bill,
Wouldn't the 2 hoses that go into the heater core have to be conected together with some type of copper tubing to "continue the flow", ie the tubing would in effect be "replacing" the heater core? I am looking for a "temporary" fix. So, now I am thinking about taking the heatercore completely out of the system and replacing it with a piece of tubing. Would this work?

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D Smith
ALABAMA
1970 Chevelle 350


[This message has been edited by 70Chevelle 350 (edited 10-22-99).]

heater cores are indeed delicate...when removing hoses from a healthy core always make longitudinal slits thru the hose ends where they overly the core nipples ....then loosen gently so you dont damage the core...

coolant can eat your carpet so if you dont want to end up replacing it, get it out and rinsed ...bypass the core as mentioned above till you can fix it but be sure to rinse the core out as well while the carpet is out to get all the ccolant out so it doenst recontaminate the carpet after you put it back in...

70,
Either way will work just fine. Either the bolt or tubing. It's just a rerouting of the water to flow thru the heater core. It doesn stop the flow from/to the radiator or water pump.
Fred

[This message has been edited by Riffers70 (edited 10-22-99).]

Doesn't GM sell a lesk stop that's suspose to work extremely well. BTW, you don't need to connect the hoses together. If you want you could put plugs in the pump and manifold.

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Pat Kelley
66 El Camino, daily driver
67 El Camino, STRIP/street

So when I do have the core replaced, how much would I expect a local shop to charge for parts and labor. I don't plan on doing this myself. Thank again...

Pat, are you talking about putting plugs directly into the Manifold and Water Pump or the end of the hoses coming from them?

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D Smith
ALABAMA
1970 Chevelle 350


[This message has been edited by 70Chevelle 350 (edited 10-22-99).]

Heater cores are very simple to fix. Take it out of its housing by unscrewing 5 or 6 screws from underneith the hood. Take out the heater core, and fill it up with water and shake it around to find out where the leak is coming from... Then just squirt a little liquid weld in the hole and let it dry!! I have fixed 3 heater cores doing this... It is really simple. Otherwise if you dont want to bother taking it out, just rip out the two ends of heater hose that go into the heater core and connect them together with hose clamps and a small copper pipe.

The chain auto parts stores sell a little fitting that's 3/4 on one end and 5/8 on the other, just the thing for hooking those together.

Tom (it's better to have circulation so hot water will move by the thermostat, IMO)

Go with the Bars Leak I used it to seal a head gasket that was seeping works great and will NOT plug rad.GM put in cars right on the line when the were using steel shim head gaskets.Never a problem, the water soluble oil is lube for the water pump.Used it on the road one time to stop a leak in rad on my log truck that had be hit with a stone the water was shooting 4' out the front poured in in and watched the leak stop, just about that fast.And that was a rad 5 times bigger than a car rad and 10 times more expensive,one jar was all it took.And no I don't sell the stuff,maybe I should...FRED

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"Pat, are you talking about putting plugs directly into the Manifold and Water Pump or the end of the hoses coming from them?"

You could do either. Both my ECs have plugs in the pump and manifold. While Chevelles with Four Seasons A/C have water going through heater core all the time (know as a reheat system), non A/C cars have a valve that shuts off the flow to the heater when it's not in use. Pluging the heater lines is the same as turning off the heater in a non A/C car.

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Pat Kelley
66 El Camino, daily driver
67 El Camino, STRIP/street

OK guys, need a concensus. Fred from Ontario say go with the Bars Leak, and Riffers says no. I would like to go the Bar's Leak way but I do not want to hurt my engine. Remeber, the leak started AFTER I flushed the radiator with "flush" and water. This tells me that something was "plugging" the hole already. Keep those ideas coming!!!

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D Smith
ALABAMA
1970 Chevelle 350

Ok, here's another vote for Bars Leaks! I have witnessed the same thing Fred has, it does work, and is not harmful to anything. Funny thing, tho, it looks like little rabbit turds in a jar of molasses, but sure works good.

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70 & 1/2 RS Camaro
SB406 & M20 4spd
9" Rear
70 Malibu
SB350 & TH400

Gold Member # 103




[This message has been edited by Scooter (edited 10-23-99).]

I have used Bars Leak in the past with few if any problems although I havent had to use it in years....GO FOR IT

Spent many years in a gas station back when they actually worked on cars. Used many a bottle of good ole Bars. Stuff works well and never had a problem except with certain FoMoCo cars that would stop up the heater core. Apparently they had very small cores or something. Good stuff as far as I'm concerned. tom

You suit your self but if you don't have the cash now I would just uste the copper tubing trick and connect the two hose together. The reason it started after you flushed the system is that you shook some rust loose that was plugging a thin spot. And then the leak started. The bars leak may be fine for some but not for me. If you were stranded along the road some where this may be fine but I would stay away if I could Good luck. Slime

Why nott just bupass the core and run the one hose from the water pump to the intake.

Mark

Well 70...it looks like the majority like the Bars idea. And I know for a fact that several have a GREAT DEAL more experience than I. I have used it in the past, specifically to stop a head gasket leak. Worked like a charm and saved me about $200 temporarily. I have plans on converting the heads to hard seats, but now is not the time.
Look at it this way: Right now your heater core leaks. If you use the bars and it works...GREAT. If you use the bars and it clogs up the heater core, it probably needed replacing anyway, then just bypass the core and bundle up.
As far as replacing the heater core, it's really not difficult, just time consuming. A new heatercore could cost you $30 w/ac or $45 w/o ac.
Good Luck to ya!

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Better Late than Never Fred
Team Chevelle #400
Madness takes it's toll, please have exact change.
www.geocities.com/motorcity/shop/9385/1970Chevelle.html (http://www.geocities.com/motorcity/shop/9385/1970Chevelle.html)

Riffers,
What are the signs and symptoms of a clogged heater core? I have heard this problem mentioned several times. Thanks again!!

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D Smith
ALABAMA
1970 Chevelle 350

hmm...chattering teeth...blue fingers...fogged windows that won't unfog no matter how high you turn up the fan...
heheh...hey..go for it..see what happens http://www.chevelles.com/forum/smile.gif

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Better Late than Never Fred
Team Chevelle #400
Madness takes it's toll, please have exact change.
www.geocities.com/motorcity/shop/9385/1970Chevelle.html (http://www.geocities.com/motorcity/shop/9385/1970Chevelle.html)

I say bite the bullet, spend the $40 for the heater core and have some fun for a couple of hours under the dash.. all the time spent worrying about what to should be spend doing it! Times a wastin!

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70 chevelle ss396 conv
66 chevelle ss396 hdp/conv
55 chevy prostreet

Another vote for the Bars. http://www.chevelles.com/forum/smile.gif Then if it works, you can replace it next summer. Not too bad. Just follow the instructions already given. Unbolting inner fender will speed things for sure (at least unbolt most of the way). Core comes out of the box under dash once unbolted.
Good luck. http://www.chevelles.com/forum/smile.gif http://www.chevelles.com/forum/smile.gif

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Mr. D
72 454 Elcamino
68 RS/SS camaro
73 RS/LT/Z28 camaro
99 Firebird TA WS-6 A4

Hey Riffers,
Nice gold Chevelle. Looks just like mine except for the black vinyl top! Anyway, are you saying signs of a clogged heater core are that it doesn't put out ANY heat at all, and fogged windows?

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D Smith
ALABAMA
1970 Chevelle 350

Thanks! http://www.chevelles.com/forum/smile.gif Actually I was being a smarta$$ with that response, sorry. I've never had a clogged hearter core myself so I can;t tell you first hand. But I would say you wouldn't get any heat from it at all. If you have no hot water cirtulating through the core then you have no heat source when the fan blows air past it. In all honesty I wouldn't worry about clogging the heater core, try the Bars and see what happens. Hopefully it will plug that leak and you can take care of it in the spring. Otherwise, if you bypass the heatercore it will be a cold winter in that car. If you have the $40 and a few hours to spend "under the hood" it'd be a great experience for you. It's really not difficult to do, and it's really rewarding when it works!

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Better Late than Never Fred
Team Chevelle #400
Madness takes it's toll, please have exact change.
www.geocities.com/motorcity/shop/9385/1970Chevelle.html (http://www.geocities.com/motorcity/shop/9385/1970Chevelle.html)


[This message has been edited by Riffers70 (edited 10-26-99).]

Thanks Riffers. I do have plenty of heat, but I am getting very fogged - up windows. You had mentioned this and was just curious if it was due to the heater core. Even rolling down the windows doesn't clear them up. ???

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D Smith
ALABAMA
1970 Chevelle 350

I had a small antifreeze puddle on my passenger floor recently. It turned out to be loose clamps on the heater connections in the engine compartment at the firewall. I did not want to damage them when installing the hoses, so did not get the hoses tight enough. The antifreeze followed the fitting through the firewall and ended up on the floor. A quick turn of the hose clamp screw fixed it. Worth a try.

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Gotta have a Chevy !In Durham N.C.
Why is there never enough time or money to do it right the first time, but ALWAYS enough to do it over?
Make it look the way you like it, forget what the other guys say!

Oh yeah most definitely. A leak in your heatercore will cause this. Think of it as the effect of a hot shower on a mirror. Same principle. The fogged windows are a direct result of the leak. Fix the leak (replace core or try Bars) and that won't happen.

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Better Late than Never Fred
Team Chevelle #400
Madness takes it's toll, please have exact change.
www.geocities.com/motorcity/shop/9385/1970Chevelle.html (http://www.geocities.com/motorcity/shop/9385/1970Chevelle.html)

Let's not make a project out of it. Why not just install a new heater core. Without a/c it only takes about a half hour. Chevelles are real easy. At least you'll feel better knowing that you have a nice new heater core, and you won't have to worry about that stuff I just poured in my cooling system. While you're at it you may want to install a new heaterbox seal kit wile the heaterbox is out.


Good luck!

Jeff

It has been my experience that there is no repair on a Chevelle that only takes a half of an hour. You will start by removing the heater core and then you will think "Gee, that firewall is looking pretty crudy...and while I am at it, I should replace that XXX or YYY" ....next thing you know, your engine is pulled and you are doing a frame-off restoration! AHHHHHH!!! Bad flashbacks on my '69 Chevelle...sorry guys.

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Bruce M.
Buffalo, NY
Team Chevelle #197
69 SS Chevelle
80 Malibu
members.aol.com/amhpd17/index.html (http://members.aol.com/amhpd17/index.html)

70,

It appears that you have a lot of advice already, but I feel I should make a point. You mentioned that you just had your system flushed. Another question would be, how long has it been since you had the radiator itself cleaned, as in dipped and flushed? If that has been done in the not so distant past, I would very highly recommend that you NOT use the Bar's. The Bars is a material when heated thins out, as in water soluable. It isn't truely an oil, but it will suspend in the water while the car is at temperature.

When the car cools down, the material adheres itself to the walls of the coolant system. Even while the vehicle is running it will tend to fill the leak because it is in a gummy state and won't fit through the pinhole leak.

Here is the problem that I see with that. Keep in mind that that stuff coats the inside of the entire coolant system. That will make your radiator less effective, slightly. It restricts flow, reduces cooling efficiency, and cannot be removed. It is just something that you don't want in your radiator in the first place. You want a clean coolant system.

My vote would be to replace the heater core. Just did the same thing on my 59 Elky and expect to do my 70 Elky soon. For a temp fix, as has been suggested, remove the hoses from the heater core at the fire wall and join them together with the short stretch of copper tubing. Then tear the heater core out on the weekend. It really isn't that challenging.

I know that the Bars works, but it really isn't something that I would want in my cooling system. If you have the chance to fix the problem right, do it right the first time. http://www.chevelles.com/forum/smile.gif

As for the half hour job. That ins't a bad estimate, but I have to laugh with Bruce. It is amazing how some small jobs turn into HUGE restorations. http://www.chevelles.com/forum/smile.gif I think every car enthusiast worth his salt tends to do this. That is the nature of hot rodding. There isn't a day that goes by that I don't look at one of my hot rods and see a long list of things that I would like to do to it to make it better, faster, better looking, etc. Those types of ambitions are great, but they certainly breech the line of practicality for everyday driving. In other words, you need a fix right away, so do the best you can with what you have. As you work on your car, you will find things that you would like to do later. Keep track of those things and take care of them one at a time, eventually, you will have a screamin ride that the magazines would clamour to cover. http://www.chevelles.com/forum/smile.gif

Post your decision, I would love to hear what you decide and how you fix it. Let us know if you have any other questions.

i used barrs leak in my cougar and it plugged the radiator BIG time...i too used barrs some 20 yrs ago with no problem so
i never suspected the barrs leak was the source of my overheating problems until,
$650 later, after replacing EVERYTHING else, i had the radiator pulled only to find that barrs leak works TOO WELL if you catch my drift!

im with stinky...no more barrs or other leak stop for me!!! fix it right!!

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Rich
Cocoa Beach, Fla
Team Chevelle #380
wa3men@aol.com
www.chevelles.com/showroom/70_SS_454.jpg (http://www.chevelles.com/showroom/70_SS_454.jpg)




[This message has been edited by 70 SS 454 (edited 10-27-99).]

And Rich I'll go back to what I said in the first place.GM used this on the assembly line it went in every car comming off the line.I have it in my small block because I had a steel shim gasket seeping after the engine was shut down it would miss fire till it burned clean, after Bars no more trouble that was 5000 miles ago.Your car do as you please,sure flogged the hell out of that one...FRED

Poured the Bars in and it stopped leaking. I'll admit that it didn't work imeadiatly though. Opened the radiator cap and that stuff is EXTREMELY GUMMY!!!! Anyway, I chose not to fix it the correct way right now because I just finished changing ALL fluids, new plugs, wires, distributor, new master cylinder, etc. So, as you can see, I am kinda needing a break from working on the Chevelle. I will probably get after the core next spring. But I do appreciate and enjoy all of the comments, and suggestions from all. What a great web site!!!!!!!!!!

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D Smith
ALABAMA
1970 Chevelle 350

Fred...my probelm was in a 89 cougar...i have used barrs before years ago with no problem...is it possible that the newer rads are more sensitive to plugging than our older chevelle rads..esp aluminum with MUCH larger core sizes??
i have also heard that every car off the gm line had barrs so i dont question your info...
70 Chevelle 350...just remember my experience so IF you do start to run a little hot you will do the rad 1st...and not blow big bucks as i did !!!
tho on your chevelle i dont think you COULD spend $650 before you got to the rad!!!

ahhh the price of hi tech...ill take my chevelle any day!!
regards to all!

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Rich
Cocoa Beach, Fla
Team Chevelle #380
wa3men@aol.com
www.chevelles.com/showroom/70_SS_454.jpg (http://www.chevelles.com/showroom/70_SS_454.jpg)




[This message has been edited by 70 SS 454 (edited 10-28-99).]

This is going to sound like it's WAY out in left field, but once upon a time I used pepper to fix those small irritating glycol leaks. It worked & I did not experience overheating problems or pump failures.

It's a pay your money, take your chances deal, but it worked more than once for me on differnet vehicles.

I used black pepper, about a tablespoon full in the rad, take her out and let her get warm. If it's the heater core, you'll have to run the heater to get the pepper there.

Remember - PEPPER. I tore down an engine once that got cooked beacause the owner couldn't remember what you were supposed to use, and he tried oatmeal. Long story short, that didn't work too well....

i'm with you fatherwes , just like i said in my previous reply , - pepper . i've seen it work as long as the hole is not too big . but , it is ultimatly up to what 70chevelle 350 feels comfy using on his ride .