Coolant system troubles and heater core hole - The 1947 - Present Chevrolet & GMC Truck Message Board Network

apstguy · 11-30-2003, 05:19 PM

There was a little puddle of coolant under my truck wednesday so I popped the hood and it was coming from the heater hose where it went to the heater core. One of the hoses looked like it had never been replaced. It was glued on! I went to Kragens and got new heater hoses, upper radiator hose, heavy duty thermostat, seal, clamps, and coolant. Came home and changed all the hoses & flushed it out many times. (Lower radiator hose was replaced not too long ago and still looks new) I had oodles of fun getting on of the heater hoses off since it was so old it glued itself to the firewall and the heater core. Everything went well. Next day I am on the freeway with the hear on and I give it a little gas to pass someone. SPLOOSH! I get coolant all over the passenger footwell. &^#$! So lucky me gets to replace the heater core! They didn't have the heater core in stock so I put bypass caps on the radiator and engine. DO you guys have any tips on replacing the heater core? (IE, how to get the ventilation system out)

Now I am without heat or A/C. Seems like the ventilation system is useless now.

My radiator hose inlet on the engine was quite corroded, but it was mostly superficial. The thermostat was rusty and the intake manifold's coolant pathways were bright orange rust. Is that normal? I'm glad I replaced my thermostat because it looked quite old. It could have failed any time.

I should have known it was the heater core when I hooked it up to the garden hose to flush it and the water ran out bright ornge rust for quite a long time.

GRRRRRRRRRRRRRR!!!!!!!!

78SilveradoSWB · 11-30-2003, 05:30 PM

Tyler:

Here is some information that may help:

http://coloradok5.com/heatercore.shtml

Going to do this myself when I get around to doing it.

apstguy · 11-30-2003, 05:37 PM

THANK YOU! Just what I needed. Now I can get to it Tuesday.

Grim Reaper · 11-30-2003, 10:08 PM

ALWAYS cut the hoses off the heater core. It doesn't take much yanking around to cause a crack in the core. 5/8s bottom 3/4 to top and the bottom goes to the intake. It will trap air if you get it backwards and may not perform as well.

Cole's 87 · 11-30-2003, 10:15 PM

What ever you do make sure you pull the carpet so the padding can dry. I didnt do that I just put a fan in the floor board...wrong about a month later I needed to get to some speaker wires and when I pulled the carpet up

I hope you get the picture.

Mike76251 · 12-01-2003, 12:28 AM

It is not that big a deal to drop the heater box from under the dash.
I had to put on a new core a few years ago and it didn't take long.
Oh yeah.....I second that post about always cutting off the heater hoses with a razor blade.

apstguy · 12-01-2003, 03:55 AM

I did but the damage was already there before I did anything to it. It was rusted like a mofo anyways. One of the hose was GLUED to the heater core. Part of the old hose is still stuck on it because it wouldn't come off. Still seals around it well but who cares now that I'm getting a new one.

I did get the hoses right no problem there.

MylilBowTie · 12-01-2003, 09:34 AM

Ive change mine before and never needed to....

It was just my old hoses. I replaced those and a year later its doing it again with the new core.

11-30-2003, 05:19 PM	#1
apstguy LED King Join Date: Jan 2003 Location: Sacramento, CA Posts: 2,087	Coolant system troubles and heater core hole There was a little puddle of coolant under my truck wednesday so I popped the hood and it was coming from the heater hose where it went to the heater core. One of the hoses looked like it had never been replaced. It was glued on! I went to Kragens and got new heater hoses, upper radiator hose, heavy duty thermostat, seal, clamps, and coolant. Came home and changed all the hoses & flushed it out many times. (Lower radiator hose was replaced not too long ago and still looks new) I had oodles of fun getting on of the heater hoses off since it was so old it glued itself to the firewall and the heater core. Everything went well. Next day I am on the freeway with the hear on and I give it a little gas to pass someone. SPLOOSH! I get coolant all over the passenger footwell. &^#$! So lucky me gets to replace the heater core! They didn't have the heater core in stock so I put bypass caps on the radiator and engine. DO you guys have any tips on replacing the heater core? (IE, how to get the ventilation system out) Now I am without heat or A/C. Seems like the ventilation system is useless now. My radiator hose inlet on the engine was quite corroded, but it was mostly superficial. The thermostat was rusty and the intake manifold's coolant pathways were bright orange rust. Is that normal? I'm glad I replaced my thermostat because it looked quite old. It could have failed any time. I should have known it was the heater core when I hooked it up to the garden hose to flush it and the water ran out bright ornge rust for quite a long time. GRRRRRRRRRRRRRR!!!!!!!! __________________ Tyler 1985 C10 305 w/ Bowtie OD TH700R4 3.42 LSD 202,000 miles 2006 Ford Focus ZX3 5-speed Stick 2016 Chevy Spark EV Gone: 2002.5 VW GTI 24v VR6 Gone: 2008 VW R32

11-30-2003, 05:30 PM	#2
78SilveradoSWB Senior Member Join Date: Apr 2002 Location: Beaverton, OR Posts: 1,615	Tyler: Here is some information that may help: http://coloradok5.com/heatercore.shtml Going to do this myself when I get around to doing it. __________________ Mitch 1978 Chevrolet Silverado C 10 454 BB, TH400

11-30-2003, 05:37 PM	#3
apstguy LED King Join Date: Jan 2003 Location: Sacramento, CA Posts: 2,087	THANK YOU! Just what I needed. Now I can get to it Tuesday. __________________ Tyler 1985 C10 305 w/ Bowtie OD TH700R4 3.42 LSD 202,000 miles 2006 Ford Focus ZX3 5-speed Stick 2016 Chevy Spark EV Gone: 2002.5 VW GTI 24v VR6 Gone: 2008 VW R32

11-30-2003, 10:08 PM	#4
Grim Reaper Registered User Join Date: Jul 2001 Location: Atlanta GA Posts: 1,704	ALWAYS cut the hoses off the heater core. It doesn't take much yanking around to cause a crack in the core. 5/8s bottom 3/4 to top and the bottom goes to the intake. It will trap air if you get it backwards and may not perform as well. __________________ Grim-Reaper 70 Pontiac LeMans Sport Convertible, worlds longest resto in progress Looking for 71-72 2wd Blazer or Jimmy Project Last edited by Grim Reaper; 11-30-2003 at 10:11 PM.

12-01-2003, 03:55 AM	#7
apstguy LED King Join Date: Jan 2003 Location: Sacramento, CA Posts: 2,087	I did but the damage was already there before I did anything to it. It was rusted like a mofo anyways. One of the hose was GLUED to the heater core. Part of the old hose is still stuck on it because it wouldn't come off. Still seals around it well but who cares now that I'm getting a new one. I did get the hoses right no problem there. __________________ Tyler 1985 C10 305 w/ Bowtie OD TH700R4 3.42 LSD 202,000 miles 2006 Ford Focus ZX3 5-speed Stick 2016 Chevy Spark EV Gone: 2002.5 VW GTI 24v VR6 Gone: 2008 VW R32

11-30-2003, 10:15 PM	#5
Cole's 87 Registered User Join Date: Nov 2002 Posts: 272	What ever you do make sure you pull the carpet so the padding can dry. I didnt do that I just put a fan in the floor board...wrong about a month later I needed to get to some speaker wires and when I pulled the carpet up I hope you get the picture.

12-01-2003, 12:28 AM	#6
Mike76251 Senior Member Join Date: Mar 2003 Posts: 2,499	It is not that big a deal to drop the heater box from under the dash. I had to put on a new core a few years ago and it didn't take long. Oh yeah.....I second that post about always cutting off the heater hoses with a razor blade.

12-01-2003, 09:34 AM	#8
MylilBowTie Right turn Clyde Join Date: Nov 2002 Location: Cincinnati, Ohio Posts: 2,911	Ive change mine before and never needed to.... It was just my old hoses. I replaced those and a year later its doing it again with the new core. __________________ 1974 C25 LWB: 454 4bbl Carb / TH400 / 3.73 1992 Camaro RS 305 TBI



Register or Log In To remove these advertisements.

Register or Log In To remove these advertisements.