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Heater Hose Confusion [message #359609] Mon, 19 October 2020 17:49 Go to next message
Jeremy Sanford is currently offline  Jeremy Sanford   United States
Messages: 35
Registered: August 2018
Location: Sacramento CA
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Member
Really confused by my heater hoses. I have the water heater preheat loop in place.
The hoses running back to the water heater preheat are 5/8" for sure.
What size hose goes from the T at the back of the manifold to the heater core?
What size hose goes from the T at the front of the engine by the water pump to the heater core?
If I need to replace both Ts what sizes do I need?

Thanks!


Jeremy Sanford
Sacramento, CA
1977 Kingsley
http://www.gmcmhphotos.com/photos/u42733-jsanford.html

 

Re: Heater Hose Confusion [message #359618 is a reply to message #359609] Mon, 19 October 2020 20:44 Go to previous messageGo to next message
C Boyd is currently offline  C Boyd   United States
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Registered: April 2006
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Senior Member
Sir, the rear is a 5/8” inline with a 5/8” T. The front is 3/4” inline with a 5/8” T. Both are metal. Both lines going back to water heater are 5/8”. 5/8” from rear to heater core and a 3/4” from front to heater core.





Jeremy Sanford wrote on Mon, 19 October 2020 18:49
Really confused by my heater hoses. I have the water heater preheat loop in place.
The hoses running back to the water heater preheat are 5/8" for sure.
What size hose goes from the T at the back of the manifold to the heater core?
What size hose goes from the T at the front of the engine by the water pump to the heater core?
If I need to replace both Ts what sizes do I need?

Thanks!


C. Boyd
76 Crestmont
East Tennessee
Re: Heater Hose Confusion [message #359622 is a reply to message #359618] Mon, 19 October 2020 22:50 Go to previous messageGo to next message
Jeremy Sanford is currently offline  Jeremy Sanford   United States
Messages: 35
Registered: August 2018
Location: Sacramento CA
Karma: 1
Member
Thank you!


Jeremy Sanford
Sacramento, CA
1977 Kingsley
http://www.gmcmhphotos.com/photos/u42733-jsanford.html

 

Re: [GMCnet] Heater Hose Confusion [message #359623 is a reply to message #359618] Mon, 19 October 2020 22:53 Go to previous messageGo to next message
jimk is currently offline  jimk   United States
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Registered: July 2006
Location: Belmont, CA
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Senior Member
On Mon, Oct 19, 2020 at 6:45 PM Charles Boyd via Gmclist <
gmclist@list.gmcnet.org> wrote:

> Sir, the rear is a 5/8” inline with a 5/8” T. The front is 3/4” inline
> with a 5/8” T. Both are metal. Both lines going back to water
> heater are 5/8”. 5/8” from rear to heater core and a 3/4” from front to
> heater core.
>
>
>
>
>
> Jeremy Sanford wrote on Mon, 19 October 2020 18:49
>> Really confused by my heater hoses. I have the water heater preheat loop
> in place.
>> The hoses running back to the water heater preheat are 5/8" for sure.
>> What size hose goes from the T at the back of the manifold to the heater
> core?
>> What size hose goes from the T at the front of the engine by the water
> pump to the heater core?
>> If I need to replace both Ts what sizes do I need?
>>
>> Thanks!
>
>
> --
> C. Boyd
> 76 Crestmont
> East Tennessee
>
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> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
Almost all the coaches we work on has rubber hoses.
Am i misunderstanding?


--
Jim Kanomata
Applied/GMC, Newark,CA
jimk@appliedairfilters.com
http://www.gmcrvparts.com
1-800-752-7502
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Jim Kanomata
Applied/GMC
jimk@appliedairfilters.com
www.appliedgmc.com
1-800-752-7502
Re: [GMCnet] Heater Hose Confusion [message #359625 is a reply to message #359623] Mon, 19 October 2020 23:12 Go to previous messageGo to next message
Jeremy Sanford is currently offline  Jeremy Sanford   United States
Messages: 35
Registered: August 2018
Location: Sacramento CA
Karma: 1
Member
Jim,

I was/am trying to figure out what size rubber heater hose goes where. 5/8" and 3/4"


Jeremy Sanford
Sacramento, CA
1977 Kingsley
http://www.gmcmhphotos.com/photos/u42733-jsanford.html

 

Re: Heater Hose Confusion [message #359627 is a reply to message #359609] Tue, 20 October 2020 00:15 Go to previous messageGo to next message
mrgmc3 is currently offline  mrgmc3   United States
Messages: 210
Registered: September 2013
Location: W Washington
Karma: 2
Senior Member
Jeremy, whatever you do, don’t just pull the hose going to the bathroom water heater out. You must use the old hose to pull the new hose through the floor and behind the fridge. If you just pull the old hose out, you’ll never be able to feed the new hose through by itself.

Chris Geils - Twin Cities / W Wa 1978 26' Kingsley w/ very few mods; PD9040, aux trans cooler, one repaint in stock colors, R134a, Al rad, Alcoas, 54k mi
Re: Heater Hose Confusion [message #359631 is a reply to message #359627] Tue, 20 October 2020 07:57 Go to previous messageGo to next message
tphipps is currently offline  tphipps   United States
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Registered: August 2004
Location: Spanish Fort, AL
Karma: 9
Senior Member
While you are working on these long hoses, consider installing cut off valves. Might save your engine. I had my GMC worked on by one of our professional shops. They noticed a bubble in one of the hoses, cut it out and used a PVC spacer to jump the gap. PVC failed due to plastic fatigue, in 400 miles.
Cost one 455.
Tom


2012 Phoenix Cruiser model 2552 KA4CSG
Re: Heater Hose Confusion [message #359632 is a reply to message #359609] Tue, 20 October 2020 08:53 Go to previous message
rgogan is currently offline  rgogan   United States
Messages: 82
Registered: February 2004
Location: Milwaukee, WI
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Member
Those "bubbles" in the heater hoses that I call "aneurysms" can certainly kill engines when they burst. Please see my post on silicone hose replacement. I have had these silicone heater hoses for 10 years and with regular thorough inspection, they show no sign of failure. They are as supple as the day they were installed.

Remember the experience with the rubber oil fill tube that would fail and dump oil all over the ground? The problem was solved with a silicone elbow replacement.
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