Topic: LEAK - under dashboard - new radiator

[via3d]

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

[SA74SD]

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.

[via3d]

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

[SA74SD]

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.

[Wallington]

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.

[SA74SD]

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.

[via3d]

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

[81Turbo TA]

Check this
https://youtu.be/TF0n0p6HMPc

[Wallington]

The colour could be a reaction between coolant and fresh radiator along with old stained coolant passages. You're not just using straight water?

[via3d]

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