Q: New radiator, but no heater hose nipple! - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Cap'n Hook · 08-24-2003, 08:50 PM

Gotta new 4-core radiator for the Jimmy from PartsAmerica but there's no prevision for the return heater hose. Can I just run it back to the water pump, instead?

Thanks guys, and great forum!

adamls · 08-24-2003, 08:57 PM

No, the water needs to make a complete circle that goes through the engine and then through the radiator. If you send it right back into the pump then it will never cool off.

Cap'n Hook · 08-24-2003, 09:02 PM

So, then how do I get this back to the tank? Do I need to go have a new nipple fitted to the new radiator for this hose?

Guess I know why I only paid $150 for this thing now!

tom hand · 08-24-2003, 09:21 PM

Yes you can run it off the intake and back to the water pump...that's how mine was run from the factory. I have never seen a 67-72 that had the nipple on the radiator from the factory, I aways thought that was a 73 up thing,[and the radiator will bolt right in] but these trucks were built at several different places so there is no telling

**68 Stepside** · 08-24-2003, 09:31 PM

I agree with Tom. Millions of GM cars/trucks have one hose running to the pump, and the other to the tank. You should have no problems doing it that way.

Cap'n Hook · 08-24-2003, 09:35 PM

Ya'll are confusing me! Ok, the intake is already used to feed the heater core, and the return line was going back to the radiator, directly from the heater core. Now this new radiator doesn't have a prevision for this return line from the heater core, so I was gonna run it to one of the two holes in the water pump, one being on top and the other on the passenger side of the water pump, using the latter of the two! Seems to me, once the thermostat opens up, all the coolant will be cooled!? Yes/No?

tom hand · 08-24-2003, 09:49 PM

Yes run it to the hole on the passenger side of the waterpump it will work fine...this is for the heater it has nothing to do with cooling the engine

Cap'n Hook · 08-24-2003, 09:59 PM

Just a question, but then why did the radiator Im replacing have the return heater core hose running to the radiator? Maybe a wrong replacement radiator previously, or something of the nature?

And I'll be picking up some new parts tomorrow, including the thermostat housing, thermostat and upper and lower radiator hoses, and the bung to fit the water pump for the return heater hose! Im thinking 195 degrees is a bit too hot to run here in Texas summer heat, but 160 is too cool for winter. So I'm gonna pickup a 185 thermo! These have to be the original thermostat housing and metal upper radiator hose, cuz they both have rusted pieces inside them, some pieces bigger than my small finger nail!

jef5150 · 08-24-2003, 10:00 PM

manual tranny and auto tranny radiators are hooked up differently,,,,,,,,,,,,,,,,,,,,,,,,,,

**FRENCHBLUE72** · 08-24-2003, 10:03 PM

It seem's to me the truck's with automatic's had the hose going to the radiator and manual's had the water pump action going.. But I could be way off base.

Solver · 08-24-2003, 10:07 PM

Most of the trucks I have had the radiator had a port on it for the heater. The aftermarket radiators I have ordered do not have this port on them now.I wonder if anyone makes it that way anymore.I have had to use the spare port on the water pump.That plug on the water pump is kind of hard to unscrew after 30 some years

Cap'n Hook · 08-24-2003, 10:07 PM

Supposedly this is the radiator for my application, AT with A/C! Didn't really pay attention to the heater hose bung not being there in the picture before I ordered!

jef5150 · 08-24-2003, 10:28 PM

they are routed differently.........jeff

Hotrod70C10 · 08-25-2003, 12:01 AM

That's interesting! I've got the typical v8 manual trans hose setup on mine. It is a factory 350 w/ th-350 tranny. I'm guessing the radiator was replaced some time ago before I bought it though.

JimKshortstep4x4 · 08-25-2003, 10:39 AM

My radiator repairmen tells me that he has seen the nipples on the radiators mainly on vehicles with AC. It also makes sense that automatics could benefit from the return being in the radiator. If it were my vehicle and it had air, I would want the nipple on the radiator.

Jim

Bill72BB · 08-25-2003, 10:59 AM

When I ordered mine it had the return to the radiator , it was a Modine .

adamls · 08-25-2003, 11:11 AM

Now, I am confused.

Maximum Overdrive · 08-25-2003, 12:12 PM

I have had a few automatics and none of them had a return line for the heater core on the radiator. Only tranny fluid lines to them. They all had the set up of the heater core hose going back to the waterpump.

Alex · 08-25-2003, 12:21 PM

Mine (no A/C) had the heater hose nipple and I replaced it (2 core) with a 4 core radiator with no nipple so I took it to the local radiator shop to have one installed. I lucked out as the guy did it for free.

72c10step · 08-25-2003, 02:04 PM

I bought a replacement radiator for my truck a month or two ago. It came with the heater line fitting on it, as well as the tranny cooler line fittings. The old one I removed had the same setup. My truck has a 350/AT and no A/C. Now only if I hadn't dropped the old Voltage Regulator, which put a pinhole leak in the brand new radiator. Doh!

Cap'n Hook · 08-25-2003, 05:10 PM

Well, my Jimmy has A/C and auto and Im gonna try rerouting the heater core return to the water pump and see what she does. I figure it being a 4-core and all, it will probably cool just fine. Also, Im getting a lower degree thermostat to compensate for the higher volume of water going thru the water pump now!

dubie · 08-25-2003, 05:15 PM

I just went through this exact same thing on the board a few weeks back. You can route the one through the intake and the other goes in through your water pump plug. I have seen both automatics and manual trannies with this exact same setup. It will work!!

**smitty62** · 08-25-2003, 05:29 PM

(A) Modine still makes the radiator with a nipple.
(B) OK to feed back into the water pump--no biggie!
(C) If you really want the nipple, take it to a radiator shop--(cheaper than return shipment if it was shipped to you)

busterwivell · 08-25-2003, 06:47 PM

I didn't have a fitting in the radiator I took out, but did on the new 4 core I got at Pomona. Just got a cap for it and secured it with a hose clamp.

Dusti · 08-25-2003, 08:02 PM

I had to go check what was in my truck,some previous owner replaced the original one with 1 that has the nipple on the radiator that is blocked off and has the conections for auto tranny lines that are not being used since its a 4-speed.

Just adding more to the confusion

Bob W

08-24-2003, 08:50 PM	#1
Cap'n Hook Workin to live... Join Date: Jun 2003 Location: Texas Hill Country Posts: 261	Q: New radiator, but no heater hose nipple! Gotta new 4-core radiator for the Jimmy from PartsAmerica but there's no prevision for the return heater hose. Can I just run it back to the water pump, instead? Thanks guys, and great forum! __________________ Jason

08-24-2003, 08:57 PM	#2
adamls Gotta Startem Early Join Date: Oct 2001 Location: Amarillo, TX, USA Posts: 364	No, the water needs to make a complete circle that goes through the engine and then through the radiator. If you send it right back into the pump then it will never cool off. __________________ 67 SWB In Progress, one piece at a time, maybe 3 years I will be finished

08-24-2003, 09:02 PM	#3
Cap'n Hook Workin to live... Join Date: Jun 2003 Location: Texas Hill Country Posts: 261	So, then how do I get this back to the tank? Do I need to go have a new nipple fitted to the new radiator for this hose? Guess I know why I only paid $150 for this thing now! __________________ Jason Last edited by Cap'n Hook; 08-24-2003 at 09:17 PM.

08-24-2003, 09:21 PM	#4
tom hand CCRider Join Date: Feb 2000 Location: Olive Branch,MS,USA Posts: 2,232	Yes you can run it off the intake and back to the water pump...that's how mine was run from the factory. I have never seen a 67-72 that had the nipple on the radiator from the factory, I aways thought that was a 73 up thing,[and the radiator will bolt right in] but these trucks were built at several different places so there is no telling __________________ 72 GMC Sierra SWB almost finished---- 84 Softail Olive Branch MS

08-24-2003, 09:31 PM	#5
68 Stepside huh? Join Date: May 2000 Location: Washington, Illinois Posts: 5,692	I agree with Tom. Millions of GM cars/trucks have one hose running to the pump, and the other to the tank. You should have no problems doing it that way. __________________ Someday when I'm lonely, Wishing you weren't so far away, Then I will remember Things we said today. RIP El Jay

08-24-2003, 09:35 PM	#6
Cap'n Hook Workin to live... Join Date: Jun 2003 Location: Texas Hill Country Posts: 261	Ya'll are confusing me! Ok, the intake is already used to feed the heater core, and the return line was going back to the radiator, directly from the heater core. Now this new radiator doesn't have a prevision for this return line from the heater core, so I was gonna run it to one of the two holes in the water pump, one being on top and the other on the passenger side of the water pump, using the latter of the two! Seems to me, once the thermostat opens up, all the coolant will be cooled!? Yes/No? __________________ Jason

08-24-2003, 09:49 PM	#7
tom hand CCRider Join Date: Feb 2000 Location: Olive Branch,MS,USA Posts: 2,232	Yes run it to the hole on the passenger side of the waterpump it will work fine...this is for the heater it has nothing to do with cooling the engine __________________ 72 GMC Sierra SWB almost finished---- 84 Softail Olive Branch MS

08-24-2003, 09:59 PM	#8
Cap'n Hook Workin to live... Join Date: Jun 2003 Location: Texas Hill Country Posts: 261	Just a question, but then why did the radiator Im replacing have the return heater core hose running to the radiator? Maybe a wrong replacement radiator previously, or something of the nature? And I'll be picking up some new parts tomorrow, including the thermostat housing, thermostat and upper and lower radiator hoses, and the bung to fit the water pump for the return heater hose! Im thinking 195 degrees is a bit too hot to run here in Texas summer heat, but 160 is too cool for winter. So I'm gonna pickup a 185 thermo! These have to be the original thermostat housing and metal upper radiator hose, cuz they both have rusted pieces inside them, some pieces bigger than my small finger nail! __________________ Jason Last edited by Cap'n Hook; 08-24-2003 at 10:03 PM.

08-24-2003, 10:00 PM	#9
jef5150 Inline 69 Join Date: Apr 2003 Location: valleysprings,california Posts: 1,018	did you order the correct radiator???????????? manual tranny and auto tranny radiators are hooked up differently,,,,,,,,,,,,,,,,,,,,,,,,,,

08-24-2003, 10:03 PM	#10
FRENCHBLUE72 PROJECT 7DEUCE Join Date: Dec 2002 Location: GRANTS PASS OR Posts: 21,604	It seem's to me the truck's with automatic's had the hose going to the radiator and manual's had the water pump action going.. But I could be way off base. __________________ GO BIG GREEN GO DUCKS MEMBER #6377 72 k-5 daily driver 6'' lift 35'' 350-350-205 slowly getting rust free. Project "7DEUCE" check out my build http://67-72chevytrucks.com/vboard/s...d.php?t=267665 Tim Powell..R.I.P EastSideLowlife..... R.I.P..

08-24-2003, 10:07 PM	#11
Solver Registered User Join Date: May 2000 Location: Storm Lake, Ia Posts: 1,449	Most of the trucks I have had the radiator had a port on it for the heater. The aftermarket radiators I have ordered do not have this port on them now.I wonder if anyone makes it that way anymore.I have had to use the spare port on the water pump.That plug on the water pump is kind of hard to unscrew after 30 some years __________________ 1972 Cheyenne Super 20 LWB-Blue 1972 Cheyenne Super 10 LWB-Black 1972 Cheyenne Super 10 LWB-Red 1972 Cheyenne Super 10 LWB-green 1972 GMC 4x4 LWB-White 1971 Cheyenne 10 LWB-Ochre 1971 Cheyenne 20 Longhorn-Copper 1971 Cheyenne 20 Longhorn-Black 1969 Custom 10 LWB-lt blue 1968 GMC 3/4 ton-green 1968 1/2 ton swb stepside-silver 1967 Chevrolet CST 10 LWB-green 1967 Chevrolet custom 20 LWB-Maroon

08-24-2003, 10:28 PM	#13
jef5150 Inline 69 Join Date: Apr 2003 Location: valleysprings,california Posts: 1,018	you might of ordered the wrong type they are routed differently.........jeff Attached Images

08-25-2003, 12:01 AM	#14
Hotrod70C10 Low & Slow Join Date: Dec 2002 Location: Oklahoma Posts: 1,047	That's interesting! I've got the typical v8 manual trans hose setup on mine. It is a factory 350 w/ th-350 tranny. I'm guessing the radiator was replaced some time ago before I bought it though. __________________ 70' C-10 LWB Fleetside 4.5/6 drop

08-25-2003, 10:39 AM	#15
JimKshortstep4x4 Senior Member Join Date: Jul 2001 Location: Muskegon,MI,USA Posts: 6,026	My radiator repairmen tells me that he has seen the nipples on the radiators mainly on vehicles with AC. It also makes sense that automatics could benefit from the return being in the radiator. If it were my vehicle and it had air, I would want the nipple on the radiator. Jim

08-25-2003, 10:59 AM	#16
Bill72BB Thats the Hillbilly way Join Date: Jul 2001 Location: Torrance,Ca Posts: 5,980	When I ordered mine it had the return to the radiator , it was a Modine . __________________ BILL Torrance Calif 90504 Member DUF Club Member Old Farts Club 72 3/4ton Custom Camper BB402/400 trans Dynomax Cerama-coat headers , Hei distributor ,Edelbrock 1411 air,ps,pb,leafsprings ,98 chevy 60/40 seat,S10 shoulder belts tilt,3.54 Dana 60 rear. 16" Eagle wheels with LT265/75 16 tires,Gaylord Lid,H4 headlights with 100W relay conversion. " If I knew I was going to live this long I would have taken better care of myself " Marriage changes passion...suddenly you're in bed with a relative. A GUY'S PRAYER.... Lord, I pray for a nympho with huge boobs who owns a liquor store and likes to fish and hunt and has a Harley .Amen ,



Register or Log In To remove these advertisements.

08-25-2003, 11:11 AM	#17
adamls Gotta Startem Early Join Date: Oct 2001 Location: Amarillo, TX, USA Posts: 364	Now, I am confused. __________________ 67 SWB In Progress, one piece at a time, maybe 3 years I will be finished

08-25-2003, 12:12 PM	#18
Maximum Overdrive December 21, 2012 Join Date: Apr 2000 Location: Black Eagle, Montana Posts: 1,634	I have had a few automatics and none of them had a return line for the heater core on the radiator. Only tranny fluid lines to them. They all had the set up of the heater core hose going back to the waterpump. __________________ *"!Ama Sua, Ama Kjella, Ama Lllulla!"*

08-25-2003, 12:21 PM	#19
Alex Registered User Join Date: Jan 2000 Location: Blaine, MN Posts: 798	Mine (no A/C) had the heater hose nipple and I replaced it (2 core) with a 4 core radiator with no nipple so I took it to the local radiator shop to have one installed. I lucked out as the guy did it for free. __________________ '72 C/10 LWB 402/400 Blaine, MN

08-25-2003, 02:04 PM	#20
72c10step WHYBYNU when old will do? Join Date: Jul 2003 Location: Loudon, NH Posts: 876	I bought a replacement radiator for my truck a month or two ago. It came with the heater line fitting on it, as well as the tranny cooler line fittings. The old one I removed had the same setup. My truck has a 350/AT and no A/C. Now only if I hadn't dropped the old Voltage Regulator, which put a pinhole leak in the brand new radiator. Doh! Attached Images __________________ -72 Chevy C10 Stepside -2002 Chevy Silverado 2500HD 4x4 -1984 Jeep CJ7 -1995 Polaris XCR600 Custom -2003 Honda 300ex

08-25-2003, 05:10 PM	#21
Cap'n Hook Workin to live... Join Date: Jun 2003 Location: Texas Hill Country Posts: 261	Well, my Jimmy has A/C and auto and Im gonna try rerouting the heater core return to the water pump and see what she does. I figure it being a 4-core and all, it will probably cool just fine. Also, Im getting a lower degree thermostat to compensate for the higher volume of water going thru the water pump now! __________________ Jason

08-25-2003, 05:15 PM	#22
dubie Registered User Join Date: May 2000 Location: Flin Flon, Manitoba, Canada Posts: 8,855	I just went through this exact same thing on the board a few weeks back. You can route the one through the intake and the other goes in through your water pump plug. I have seen both automatics and manual trannies with this exact same setup. It will work!! __________________ My name's Tim and I'm a truckaholic My 56 Chevy shop truck build http://67-72chevytrucks.com/vboard/s...d.php?t=562795

08-25-2003, 05:29 PM	#23
smitty62 Registered User Join Date: May 2002 Location: North Carolina Posts: 1,234	(A) Modine still makes the radiator with a nipple. (B) OK to feed back into the water pump--no biggie! (C) If you really want the nipple, take it to a radiator shop--(cheaper than return shipment if it was shipped to you) __________________ Stepsides look like real trucks! Smitty

08-25-2003, 06:47 PM	#24
busterwivell Registered User Join Date: Jan 2002 Location: Sahuarita, AZ USA Posts: 2,033	I didn't have a fitting in the radiator I took out, but did on the new 4 core I got at Pomona. Just got a cap for it and secured it with a hose clamp. __________________ Bill - Tucson, AZ 47 Chevrolet 2 dr sedan 56 Chevrolet 210 2 dr sedan 66 Chevrolet Malibu 2 dr 4 speed 71 Chevrolet C30 Longhorn 86 Chevrolet Monte Carlo SS (Sold) 01 Chevrolet Tahoe IM - BUSTERWIVE@aol.com

08-25-2003, 08:02 PM	#25
Dusti Not Dusti,just Bob Join Date: Jul 2002 Location: Camas,Wa Posts: 247	Radiator I had to go check what was in my truck,some previous owner replaced the original one with 1 that has the nipple on the radiator that is blocked off and has the conections for auto tranny lines that are not being used since its a 4-speed. Just adding more to the confusion Bob W __________________ 72 cheyenne super 1/2ton 89 camaro

Register or Log In To remove these advertisements.