No hot air from heater??? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

powell72 · 11-17-2008, 11:35 PM

A buddy of mine has a '67 non-air truck that he put a motor in and now the truck has no hot air from the heater. The heater worked fine before he put the motor in. After he put the new one in, including a new waterpump, the only change he made was putting the lower heater hose off the core to the fitting on the side of the waterpump instead of the intake, where it was with the old motor. The top line from the core goes to the radiator. The truck doesn't have any air pockets in it, it runs 180 degrees all day, and the heater hoses are still cool. He put a new heater core in it thinking maybe the core had a problem, even though water flowed through it, still no change. What are we missing here? It has to be pump related, wouldn't you think? We need some fresh minds on this one.

Brad · 11-17-2008, 11:41 PM

Fwiw, I've had this happen before and it was because I was super low on coolant. It was during the winter and so my temp gauge said I was still good. I'm sure you've already checked, but it was my first thought....

powell72 · 11-17-2008, 11:50 PM

Quote:

Originally Posted by Brad

Fwiw, I've had this happen before and it was because I was super low on coolant. It was during the winter and so my temp gauge said I was still good. I'm sure you've already checked, but it was my first thought....

He says the coolant is full, I forgot to put that in my first post. Thanks for mentioning it.

463 · 11-18-2008, 12:01 AM

Chris: are you getting water flow from the heater core to the rad. are the heater hoses hot when the engine is up to temp. are the heater hoses reversed. are one or more of the heater hoses crimped or restricted in the hose. last i would plug the waterpump and hook the hose to the intake as it was.

Aarons72s · 11-18-2008, 12:06 AM

You need tto put the hose from the water pump back on the intake. Right now you have two return lines runing from the heater core. Your pressure should go from the intake to the heater core and tthe return goes to eitther the water pump or the radiator.

Willys47 · 11-18-2008, 01:51 AM

I hope this helps

67ChevyRedneck · 11-18-2008, 01:59 AM

I need to see a pic??? I can't think of a radiator that you can hook a heater hose up to???

Here's a couple pics of my old set-up.

My truck had the screwy 73+ long water pump and the alt. on the wrong side so I think I had to run my hoses like that. With my vintage air kit the bottom hose goes to the short water pump (on the passenger side of the pump) and the top hose goes to the intake. So my hoses may be "crossed" in my engine pics? It worked like that for years though

67ChevyRedneck · 11-18-2008, 02:10 AM

Also...the heater fan is working, right? Is there a lot of noise? Like it may be plugged with leaves?

Tx Firefighter · 11-18-2008, 09:28 AM

Aaron is absolutely correct. You need the one hose from the intake. The other goes to either the radiator or water pump, your choice.

67redneck, tons of radiators have a hose bung on the passenger side tank.

67ChevyRedneck · 11-18-2008, 09:46 AM

Quote:

Originally Posted by Tx Firefighter

Aaron is absolutely correct. You need the one hose from the intake. The other goes to either the radiator or water pump, your choice.

67redneck, tons of radiators have a hose bung on the passenger side tank.

Learn somethin' new...

powell72 · 11-18-2008, 10:48 PM

Great, thanks all for the help, I'll let him know to put the line back in the intake.

11-17-2008, 11:35 PM	#1
powell72 Senior Member Join Date: Jan 2005 Location: Loveland Co. Posts: 3,098	No hot air from heater??? A buddy of mine has a '67 non-air truck that he put a motor in and now the truck has no hot air from the heater. The heater worked fine before he put the motor in. After he put the new one in, including a new waterpump, the only change he made was putting the lower heater hose off the core to the fitting on the side of the waterpump instead of the intake, where it was with the old motor. The top line from the core goes to the radiator. The truck doesn't have any air pockets in it, it runs 180 degrees all day, and the heater hoses are still cool. He put a new heater core in it thinking maybe the core had a problem, even though water flowed through it, still no change. What are we missing here? It has to be pump related, wouldn't you think? We need some fresh minds on this one. __________________ Chris 74 Custom Deluxe SWB 350/350/3.73’s 99 2wd Silverado RCSB 5.3/4L60/3.90’s http://www.classictrucks.com/feature...short_bed.html

11-17-2008, 11:41 PM	#2
Brad Out of the carpool lane. Join Date: Jan 2000 Location: Clark Co, WA Posts: 5,673	Re: No hot air from heater??? Fwiw, I've had this happen before and it was because I was super low on coolant. It was during the winter and so my temp gauge said I was still good. I'm sure you've already checked, but it was my first thought.... __________________ 1968 C-10 SWB, 5.7 Vortec/700R4/3.73 posi, Torch Red 1968 Camaro, 250/Powerglide, all original (No, I'm not gonna drop a 350 in it!...Jeez!) 2000 Honda VFR in the faster yellow! 2008 Husqvarna TE-610 1967 C-10 SWB 'Six Appeal'-Gone but not forgotten...

11-18-2008, 12:01 AM	#4
463 Registered User Join Date: Nov 2007 Location: Sask Canada Posts: 1,666	Re: No hot air from heater??? Chris: are you getting water flow from the heater core to the rad. are the heater hoses hot when the engine is up to temp. are the heater hoses reversed. are one or more of the heater hoses crimped or restricted in the hose. last i would plug the waterpump and hook the hose to the intake as it was. __________________ Trueman

11-18-2008, 12:06 AM	#5
Aarons72s Registered User Join Date: Apr 2006 Location: oklahoma Posts: 10,670	Re: No hot air from heater??? You need tto put the hose from the water pump back on the intake. Right now you have two return lines runing from the heater core. Your pressure should go from the intake to the heater core and tthe return goes to eitther the water pump or the radiator. Last edited by Aarons72s; 11-18-2008 at 12:07 AM.

11-18-2008, 01:51 AM	#6
Willys47 Registered User Join Date: Dec 2007 Location: Nanaimo B.C. Posts: 604	Re: No hot air from heater??? I hope this helps Attached Images __________________ I was hooked on these trucks since 1982 when I drove my budys fathers 1968 Custum GMC 396 automatic dana 60 rear with a power lock diff what a ride more fun then we will we can ever tell!!

11-18-2008, 01:59 AM	#7
67ChevyRedneck Hittin E-Z Street on Mud Tires Join Date: Nov 2004 Location: Greenville, SC Posts: 23,090	Re: No hot air from heater??? I need to see a pic??? I can't think of a radiator that you can hook a heater hose up to??? Here's a couple pics of my old set-up. My truck had the screwy 73+ long water pump and the alt. on the wrong side so I think I had to run my hoses like that. With my vintage air kit the bottom hose goes to the short water pump (on the passenger side of the pump) and the top hose goes to the intake. So my hoses may be "crossed" in my engine pics? It worked like that for years though Attached Images __________________ Jesse James 1967 C10 SWB Stepside: 350/700R4/3.73 1965 Ford Mustang: 289/T5-5spd/3.25 Trac-Loc 1968 Pontiac Firebird: Project Fire Chicken! 2015 Silverado Double Cab 5.3L Z71 2001 Jeep Wrangler Sport 4.0L 5spd 2020 Chevrolet Equinox Premium 2.0L Turbo 2011 Mustang V6 ~ Wife's ride American Born, Country by the Grace of God 1967 CST Shop Truck Rebuild! My 1967 C-10 Build Thread My Vintage Air A/C Install Project "On a Dime" Trying my hand at Home Renovation! 1965 Mustang Modifications! Last edited by 67ChevyRedneck; 11-18-2008 at 02:09 AM.

11-18-2008, 02:10 AM	#8
67ChevyRedneck Hittin E-Z Street on Mud Tires Join Date: Nov 2004 Location: Greenville, SC Posts: 23,090	Re: No hot air from heater??? Also...the heater fan is working, right? Is there a lot of noise? Like it may be plugged with leaves? __________________ Jesse James 1967 C10 SWB Stepside: 350/700R4/3.73 1965 Ford Mustang: 289/T5-5spd/3.25 Trac-Loc 1968 Pontiac Firebird: Project Fire Chicken! 2015 Silverado Double Cab 5.3L Z71 2001 Jeep Wrangler Sport 4.0L 5spd 2020 Chevrolet Equinox Premium 2.0L Turbo 2011 Mustang V6 ~ Wife's ride American Born, Country by the Grace of God 1967 CST Shop Truck Rebuild! My 1967 C-10 Build Thread My Vintage Air A/C Install Project "On a Dime" Trying my hand at Home Renovation! 1965 Mustang Modifications!

11-18-2008, 09:28 AM	#9
Tx Firefighter Watch out for your cornhole ! Join Date: Jun 2003 Location: Azle, Texas Posts: 14,162	Re: No hot air from heater??? Aaron is absolutely correct. You need the one hose from the intake. The other goes to either the radiator or water pump, your choice. 67redneck, tons of radiators have a hose bung on the passenger side tank. __________________ I'm on the Instagram- @Gearhead_Kevin

11-18-2008, 10:48 PM	#11
powell72 Senior Member Join Date: Jan 2005 Location: Loveland Co. Posts: 3,098	Re: No hot air from heater??? Great, thanks all for the help, I'll let him know to put the line back in the intake. __________________ Chris 74 Custom Deluxe SWB 350/350/3.73’s 99 2wd Silverado RCSB 5.3/4L60/3.90’s http://www.classictrucks.com/feature...short_bed.html

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