Why is my coolant leaking out? Help!!

[tomsC10R]

A few minutes after starting the truck, coolant starts leaking out of the heater box. Out of the two holes where the coolant lines stick out. What is wrong with it? Why is it doing that? I've never had to mess around with anything to do with a heating system so I have no idea what to check.

It's a non A/C truck. It doesn't seem like the heater even works. I can't hear the blower motor kick in. After the engine really warms up you might be able to feel a little heat and a little defrost coming out, but not much.

So what should I check? What do you think is wrong with it? Is it fixable or will I need a whole new something? Sorry for all the questions, anything will be helpfull!!

Thanks in advance

[old Rusty C10]

first thing id check to see is if youre getting coolant leaking into the interior. If not you may have gotten somewhat lucky cause it may just be the hoses itself or the clamp check there. If youre sure its coming out of the heater box and not the hose its prolly the heater core. The heater core is prolly jammed and now has a leak in it which is why you havent got heat but in any event check the cables first to make sure that the doors are opening up properly

[tomsC10R]

I didn't think there was anything leaking inside, but I had to go double check, All dry Thank goodness.

The hoses and clamps are tight.

Ok, now I need a diagram, this is terrible lol... Where is the heater core actually located? Is that what is inside the box in the engine compartment? Like I said I never had to mess around with this stuff before. How much is a new heater core?

What are these doors where the heater cable goes to? I saw someone elses's post and was trying to check it out. I found the cable going from the heater switch. It goes through a softer plastic panel on the heater box. Where is the actuall door that opens? Can you see it, or do you just listen for it?

Thanks

[krue]

... Where is the heater core actually located? Is that what is inside the box in the engine compartment?

Yes that's where your heater core is.

If you want to drive it until you can fix it just take one of the hoses off that box and run it back to the engine (basically just bypassing the heater all together.) This will get you by without leaking all your coolant out.

[cdowns]

i'd be best to loosen the clamps and remove the hoses from the heater core and check to see that the nipples of the heater core aren't damaged by someone tightening the clamps too much.
as far as you not hearing the bl;ower motor first place to check is the fuse located under the dash drive side near the dimmer switch

[tomsC10R]

Krue,
Thanks for the idea of making a loop. I was going to plug the wholes in the intake and waterpump with pipe plugs. Your way will be much easier

cdowns,
Thanks. I'll make sure I check that fuse.


Does anyone know about those doors that are suppose to open?

thanks again

[krue]

The door that opens is inside the box with the heater core.

[tomsC10R]

Thanks again Krue

[walker]

You might play arond with the search function and see if you can find a thread by Jewels. She did a heater core in a non a/c truck, complete with pics. That will show you exactly what you are up against.

[walker]

Here is a link, I think.
http://67-72chevytrucks.com/vboard/s...ht=heater+core

[Martin64]

I just changed mine last week. It only took a couple of hours, but there is one bolt in particular that is a PITA. It is under the heater box on the left side (as you're facing it under the hood) up against the passenger fender. You can 't see it unless you pull the inner fender.... I passed on that and just broke tha d@mn thing off...... I got my heater core through Kragen for less than $30 and once I got there and learned they give military discounts it was even cheaper

[Tx Firefighter]

Seems like last one I did, I had to remove the right hood hinge too.

[tomsC10R]

Walker,
Thanks for the link!!

[tomsC10R]

Martin64, Tx Firefighter,
Thanks for the tips. I was actually getting the truck ready to finally put it in storage for the winter (I've had it a few weeks now) when I noticed it was losing coolant.

Luck has it that I was going to be replacing the radiator support and inner fenders this winter I've even been considering Vintage Air (before I knew the heater core took a dump) I'll have to see if I can come up with the $$$.

Thanks for all the help!!!

[Rooster's 67]

if your considering vintage air....just put in a heat and cool unit, sounds like a good excuse to me!

[dinnut]

i wish i could afford vintage air

[Martin64]

I don't know if this part was covered, but once you get everything loose, there is still the control cable for the flapper door to deal with. It's real easy, just reach in and slide it up off the post on the flapper door and when you go to reinstall everything, put that back on first.

[kevin's 4X4]

I had the same problum ! With the heater coil leaking, it was simply a hose clamp loose !

[tomsC10R]

Thanks for all the ideas and tips. I got it in storage tonight. Now I'll be able to take a better look since I won't have to contend with snow and ice anymore.

I'm trying to decide between Vintage Air and EFI (cheap used efi) Hopefully I'll be able to afford one...

Thanks again.

[gunnersm8]

yeah its easy, but you do have to pull the hinge. i actually broke my box, had to do some "epoxy fabrication"