Author Topic: LEAK - under dashboard - new radiator  (Read 1239 times)

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Offline via3d

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LEAK - under dashboard - new radiator
« on: September 06, 2017, 07:37:01 PM »
1979 Firebird TA   - Resurrecting the 'ol 'bird for myself and 16yr old son.

PROBLEM  #1:  I have a leak under the dashboard passenger side and center console area. A continuous dripping/light intermittent pour... upwards of a 1/2 gallon while it was running.

Question:  What is under the dash in the firewall that would leak?  heater core?

Considerations:
A. Brand new radiator... just installed.
B. Was running car to warm last 2 days  - doing maintenance after sitting 2 years (adjust idle, check hoses, etc. )
C. Today checked level of radiator... About a gallon low... BUT -->>  VERY black dirty looking water...
D. Flushed radiator.
E. Afterwards ran car about 15min... Leak appeared under dash... SAME dirty black looking water. About a pint leaked into plastic tub container I put down.
F. No water or bubbles in oil is visible on oil check dipstick.


Ideas Please?    head gasket?  heater core? lower intake manifold gasket?   


Thanks in advance,   Jay

Offline SA74SD

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Re: LEAK - under dashboard - new radiator
« Reply #1 on: September 06, 2017, 08:25:06 PM »
You have a bad heater core. Very common problem on these old birds. Try to get a GM core. Whatever you get, pressure check it before the install. You are looking at an 8 hr job.
Search and you can find step by step instructions. Good luck.

Offline via3d

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Re: LEAK - under dashboard - new radiator
« Reply #2 on: September 06, 2017, 08:31:19 PM »
Thanks SA74SD  !  that was a fast response and pretty confident. I suspected anyways...

Why do you think it is filthy black looking though water though?

So yes I need to replace the heater core... however do you think I have another problem as well... Like gasket material that is causing the black dirty looking water?

Jay

Offline SA74SD

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Re: LEAK - under dashboard - new radiator
« Reply #3 on: September 07, 2017, 10:17:42 PM »
Metals in block, cooling system have  had 30+ years to corrode. That will make it look black (water) . Thoroughly clean the cooling system and add  anti freeze with corrosion protection.

Offline Aus78Formula

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Re: LEAK - under dashboard - new radiator
« Reply #4 on: September 08, 2017, 07:56:51 PM »
Not sure there is such thing as a GM heater core, not in decades anyway. They are probably all made in Taiwan/China by now so try and stick with a reputable brand at least.

Offline SA74SD

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Re: LEAK - under dashboard - new radiator
« Reply #5 on: September 09, 2017, 08:34:20 AM »
I agree they are near impossible to locate. Once in a while someone who has been hoarding NOS parts will put them up for sale. Just saying.

Offline via3d

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Re: LEAK - under dashboard - new radiator
« Reply #6 on: October 12, 2017, 06:49:28 PM »
Thanks for reply guys.   Yes SA74SD was right when he said I had a heater core leak... BUT I still have the other issue re: dirty water.     

WHEW !  this is quite a job replacing the heater core. I went with an aftermarket one.
I will have to find a shop that will pressure test it for me.

The orig one appears to be all brass. Shouldn't I be fine with a Spectra after market heater core? I will check about getting it pressure tested tomorrow.

Anyways, I temporarily coupled the 2 heater hoses together... to run the car, and I still have black, sooty looking water in the radiator (brand new radiator). I have Fill and drained 4 times now and I am still getting this dirty looking water.

I will start a post on radiator flush... 

Jason
« Last Edit: October 13, 2017, 01:03:38 AM by via3d »

Offline 81Turbo TA

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Re: LEAK - under dashboard - new radiator
« Reply #7 on: October 17, 2017, 08:13:33 PM »

Offline Aus78Formula

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Re: LEAK - under dashboard - new radiator
« Reply #8 on: October 17, 2017, 08:26:50 PM »
The colour could be a reaction between coolant and fresh radiator along with old stained coolant passages. You're not just using straight water?

Offline via3d

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Re: LEAK - under dashboard - new radiator
« Reply #9 on: October 22, 2017, 01:19:40 AM »
Update:  YES, I think it is stained from age and minerals and rust.

I have performed engine flush with tee adapter on heater hose - 3 -4 times and I am now getting fairly clear water...
Was pretty dirty!

Next, when I button up the  heater core and replace tranny fluid (another critical post) ...  I will run the car to warm, (thermostat open)  and then do engine flush again...  as many times until I get clear.  :)    Appears I am on track   

I have let it idle for 20-30 min and still cannot get car to warm up... staying good and cool :)