Heater Core Leak

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68FORDJBM
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Heater Core Leak

Post by 68FORDJBM »

Can someone provide a quick overview on how to fix a leaking heater core? This is one job I've never done. Just discovered coolant dripping from the heater. Is this something that can wait - I have a long trip planned in a month and don't want to feel rushed fixing it but also don't want a huge blowout that leaves me stranded 5 hours from home.

Thanks all!

Jeff
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Re: Heater Core Leak

Post by Ohiotinkerer »

Does your ride have a/c? If not its a fairly simple process - take glove box out first, then remove the blower motor - 4-5 screws and the ground wire runs up on top of the metal part of the box - then unhook the defroster hoses - they have a plastic clamp on the bottom where they hook onto the heater box - be careful with them being as old as they are - then remove the screws holding the box on - if I remember right there's 6 of them - the one on top right inside where the glove box goes is the worst - then take the screws out of the vent attaching the vent to the passenger side kick panel. Everything should slide out and down then. You will have to remove the 2 cables that control the flaps in the box and re adjust them when you put it back together. As far as the core its pretty straightforward from there and putting it back together is pretty much a reverse of what you did. I did mine in about an hour and a half and it was the first one I ever did so its not a bad job. Take some pics before you start for a reference and you should do fine. Its something you definitely need to fix especially if you are gonna be going any distance! Hope this helps you out!......... :thup:
"Life is a garden - dig it"........... :thup:

1968 F100 2wd - Rangoon Red - 360 w/T18 - power steering and brakes
1997 Honda CBR 900RR
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sargentrs
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Re: Heater Core Leak

Post by sargentrs »

Some photos that might assist you http://www.fordification.com/forum/view ... hp?t=73960 Also, this diagram is an excellent reference http://www.fordification.com/tech/image ... heater.jpg
Randy
1970 F100 Sport Custom Limited LWB, 302cid, 3 on the tree. NO A/C, NO P/S, NO P/B. Currently in 1000 pcs while rebuilding. Project thread: http://www.fordification.com/forum/view ... 22&t=59995 Plan: 351w, C4, LSD, pwr front disc, p/s, a/c, bucket seats, new interior and paint.
1987 F-150 XLT Lariat, 5.0/C6 auto.
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68FORDJBM
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Re: Heater Core Leak

Post by 68FORDJBM »

Thanks all! Just what I needed.

No AC so hopefully pretty straightforward. Two more questions: can the core be rebuilt at a radiator shop or is it easier to replace? I'm assuming I need to drain the coolant or is there a way to to save that step? I'm probably going to drain anyway since I have a small leak in my radiator too that needs to be fixed.
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Re: Heater Core Leak

Post by DisneysPatB »

If you are not going to be needing heat, you can bypass the heater core and then fix it after your trip.
1970 F250 460 C6 - Project - Currently not running.
1999 Dodge Durango SLT 4 x 4 5.9 Magnum -not running.
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Re: Heater Core Leak

Post by Ohiotinkerer »

DisneysPatB wrote:If you are not going to be needing heat, you can bypass the heater core and then fix it after your trip.

Good thing there's lots thinking people on here because I sure didn't think to mention that....... :doh:

It's probably gonna be cheaper and easier to just get a new one - I think I paid $25 for new one at our local parts store and trying to find anyone - at least here - that does radiator work anymore is almost impossible. Its definitely a dying art in our throwaway society....... :(
"Life is a garden - dig it"........... :thup:

1968 F100 2wd - Rangoon Red - 360 w/T18 - power steering and brakes
1997 Honda CBR 900RR
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Re: Heater Core Leak

Post by Ohiotinkerer »

Ohiotinkerer wrote:
DisneysPatB wrote:If you are not going to be needing heat, you can bypass the heater core and then fix it after your trip.

Good thing there's lots of thinking people on here because I sure didn't think to mention that....... :doh:

It's probably gonna be cheaper and easier to just get a new one - I think I paid $25 for new one at our local parts store and trying to find anyone - at least here - that does radiator work anymore is almost impossible. Its definitely a dying art in our throwaway society....... :(
"Life is a garden - dig it"........... :thup:

1968 F100 2wd - Rangoon Red - 360 w/T18 - power steering and brakes
1997 Honda CBR 900RR
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Re: Heater Core Leak

Post by sargentrs »

Easier to replace that have fixed. Readily avaiable at your local parts store although they may have to ship it from their warehouse. Usually get next day at worst. For added security just take your new heater core to the radiator shop and have it pressure tested to be safe. They have been known to occasionally be defective, like any replacement part. Bypassing is the quickest alternative. You also won't have to worry about heat coming through due to worn out baffle seals.
Randy
1970 F100 Sport Custom Limited LWB, 302cid, 3 on the tree. NO A/C, NO P/S, NO P/B. Currently in 1000 pcs while rebuilding. Project thread: http://www.fordification.com/forum/view ... 22&t=59995 Plan: 351w, C4, LSD, pwr front disc, p/s, a/c, bucket seats, new interior and paint.
1987 F-150 XLT Lariat, 5.0/C6 auto.
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Re: Heater Core Leak

Post by 68FORDJBM »

Great suggestions and helping to form a strategy. I actually have an extra radiator that I need to get repaired so I can get it fixed in advanced and test the new heater core while I'm at it. I am the guy who will get the defective part from the parts store. My first alternator was defective and nearly burned up my truck:). First water pump leaked:). Yep, I'll get it tested first.

And if it all takes too long I will bypass the heater - assuming yo just connect the hoses before they pass into the truck?

Thanks all!
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Re: Heater Core Leak

Post by sargentrs »

68FORDJBM wrote:And if it all takes too long I will bypass the heater - assuming yo just connect the hoses before they pass into the truck?
Yep!
Randy
1970 F100 Sport Custom Limited LWB, 302cid, 3 on the tree. NO A/C, NO P/S, NO P/B. Currently in 1000 pcs while rebuilding. Project thread: http://www.fordification.com/forum/view ... 22&t=59995 Plan: 351w, C4, LSD, pwr front disc, p/s, a/c, bucket seats, new interior and paint.
1987 F-150 XLT Lariat, 5.0/C6 auto.
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Re: Heater Core Leak

Post by bph »

Sorry to resurrect old thread. OP asked my precise question in the thread but was left unaswered:

When replacing the heater core (in a non-AC unit) should radiator fluid be drained from any other points in the system other than at the hoses running throught the firewall into the heater?

On my 70 F250 should I be also emptying out at the radiator or engine...or merely catch what comes out at the heater inlets and then top off at the radiator when finished?

Thank you!
390FE1972
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Re: Heater Core Leak

Post by 390FE1972 »

You can either drain the radiator fluid into a container, or if you are quick you can put a container below the heater hoses and tie them up above the height of the engine about a foot high, or you can put bolts into the ends. I prefer to drain the radiator as I don't move fast enough to not make a mess. I would still put a container under the heater hose ends going into the firewall as there will be some mess either way. You could also use hose clamping pliers that stop the flow going thru the hoses. One thing, make sure to mark which hose goes to which outlet on the heater core, so you don't get confused on how they go back on, don't ask me why I know this. Also be careful not to mess up the resistor on the back of the heater box as they are not reproduced. :thup:
1972 F250 Sports Custom 390 FE C6 2WD Dana 60 4:10 gears
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Re: Heater Core Leak

Post by 1968f250429 »

68FORDJBM wrote: Sun Apr 09, 2017 8:40 pm Can someone provide a quick overview on how to fix a leaking heater core? This is one job I've never done. Just discovered coolant dripping from the heater. Is this something that can wait - I have a long trip planned in a month and don't want to feel rushed fixing it but also don't want a huge blowout that leaves me stranded 5 hours from home.

Thanks all!

Jeff
You can get a couple hose clamp off pliers to pinch off the heater hoses to avoid loosing a huge amount of coolant . Most of the auto parts stores have them in the tool aisle or find a tool company in your area to get them.
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Re: Heater Core Leak

Post by Raiver »

We may deal with a heater core leak in this '70 F250 project. The owner took it to the shop for the installation of the brake pads and tires from 4Wheelonline. The previous owner replaced the radiator two years ago so we'll see how bad it is. Gonna grab those hose clamp pliers.
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