I replaced the little hoses to the heater core, and also took off the lower radiator hose but put it back on when I decided to leave the oil sending unit alone. Obviously the coolant had been drained during this procedure. I refilled the radiator and 24 hours later I see coolant dripping off the crossover pipe. I think it was also dripping off the starter. I go inside the car and there is a small amount of coolant on the passenger side rubber floor mat. So does this mean the heater core is leaking? Would it leak both inside and outside of the car? And what could have caused it? I haven't even started the car in 2 weeks as I also am installing Casper's engine harness, oil pan gasket, etc. etc. Could I have broken one of the little pipes on the heater core when I was removing the hoses? Even if I did, the pipes are up high and as I said the engine has not been started. Thanks guys and gals.
Help me find coolant leak!
- Thread starter GNRick
- Start date
SFI Cutlass
Active Member
- Joined
- Jan 2, 2010
What I would do is pressurize your coolant system and look for leaks to be 100% sure where the leak is coming from.
The old dreaded heater core pinhole 
. If it's steaming up the windshield that's exactly what it is. It's may also just be plugged up with corrosion which may be why it's leaking on from the hose connections. Bypass the heater core like you would the throttle body hoses and see if it stops leaking.
. If it's steaming up the windshield that's exactly what it is. It's may also just be plugged up with corrosion which may be why it's leaking on from the hose connections. Bypass the heater core like you would the throttle body hoses and see if it stops leaking.I was planning on doing the pressure test. If it is the heater core, is an aluminum replacement all that is available? No more brass? Kirbans looks aluminum like the parts stores but is $8 more, plus shipping is additional. Highway Stars is out of stock. Gbody only lists it for hot air cars.
I went right down the street to autozone when my stock one went,been in the car for 7 years so far.
Im ask8ng the original poster how he removed the hoses........read the post again
I carefully cut them off with a razor blade knife. Maybe I wasn't carefull enough. Local repair shop said they might be able to fix it if it's a solder joint but since it's leaking without starting the car, I suspect it's a hole from down below. Will remove it in a day or two. Haven't pressure tested it yet though.
That copper one is made by Stant, the thermostat people. I called them to confirm the part # and they said they can't look it up as they haven't made them in years. Local repair shop said they go bad from sitting so he advised against buying an old one. The soldered joints will fail.
John Larkin
Sublime Master of Turbology
- Joined
- May 25, 2001
Core is easy to change but there are a zillion bolts holding the top of the air box together and a couple by the valve cover that are hard to find. Plus it's sealed with goo as well. Be gentle.
- Joined
- May 28, 2001
^^^ What John said.
Furthermore, the "sealer" is usually harder than the back of Superman's head. So, cutting it can be a chore.
This sealer failure is also a common source of water leaks. IE: your ecm is corroded.
Furthermore, the "sealer" is usually harder than the back of Superman's head. So, cutting it can be a chore.
This sealer failure is also a common source of water leaks. IE: your ecm is corroded.
