Novak Conversions Jeep Wrangler TJ engine mounts

Upper and Lower Heater Hoses

TallGuy

Member
Original poster
Supporting Member
Joined
Apr 26, 2025
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62
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Arizona
Hi All. Yay I blew a heater hose. Specifically the return hose from the top of the thermostat housing.

Does anyone have specific part numbers they can share? I'd like to replace both with something quality. I'm searching but getting mixed reviews. I need both upper and lower.

Looking at these Mopar - could be used tho

02 TJ 4L

Thanks in advance.
 
Are you looking for heater hoses or radiator hoses?

Heater hoses. Inlet and return from the core into thermostat housing and one goes into the water pump. I think they're two different sizes. (Not with Jeep atm. Being towed)

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Heater hoses are essentially “generic” and can be purchased at the local auto parts store. You just need to know what length you need. I think one is 3/4” diameter and the other is 5/8” diameter. Every auto parts store has rolls of heater hoses in stock, and you buy it by the foot.
 
Thanks guys! I really appreciate the guidance.

Hard lesson learned. I'm suffering the consequences of not replacing all hoses the first time. I thought this hose looked ok, but it totally split! I was ready tho. Saw the temp creep and was in the proper lane to jump off the highway right when the check gauges light popped on.

I'm hoping everything is good and no issues with the thermostat I just replaced. 😬
 
I replaced the heater hoses as well as the upper & lower radiator hoses with heavy duty silicone hoses..

Wow! Are they more durable that the Mopar series? I only wanna cry once! :ROFLMAO:


I used Gates #19038 and 19039

Nice! These are available tomorrow for me. Thinking about it.

I replaced mine last week with hoses from Crown, bought through carparts.com for $25 each. Item #'s are CR55038223AD, and CR55038128AC. They were identical sizes and shape.

Thanks I'll take a look! I'm hoping to get back up and running this week. We have a heatwave out here so I'm putting the TJ to the test for sure.
 
This isn’t worth torturing yourself over imo.

I’ve yet to have a problem with the Gates or Continental offerings…or have someone convince me I should fear them.

Rockauto provides a list of options in case you want to view them. I’ve purchased the hoses from RA and Amazon without any issues.

Your silicone hoses look good too @MikekiM
 
There she blows! I wonder if I should pull the stat and test just in case something went wrong with it which caused the pressure buildup.

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I think one is 3/4” diameter and the other is 5/8” diameter. Every auto parts store has rolls of heater hoses in stock, and you buy it by the foot.

Pretty much.

The sizes are technically 11/16” and 5/8”, but I’ve used 3/4” and 5/8” fittings for flushing without any issues…and id use those hose sizes if it weren’t so easy to purchase preformed hoses.
 
There she blows! I wonder if I should pull the stat and test just in case something went wrong with it which caused the pressure buildup.

View attachment 623889

If the radiator cap works properly, it would release pressure by sending the coolant to the reservoir.

If it were me, I’d replace any suspect hoses and run it (assuming your coolant looks healthy and your system has been running well).
 
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I have no proof of this either way but I always used silicone hoses on my twin turbo setup so, my assumption is that there is a benefit.
Plus I like the red bling.

I believe silicone generally has better longevity, holds up better to overheat temps (over roughly 257*f), better bling factor, and can be a great option for guys running custom setups.

The red looks good imo.
 
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Unsure where in AZ you are (Maricopa County?) but seems unlikely you use the heater much. Nonetheless, if the system works now - it's worth keeping functional, IMO. The 05 TJ Rubicon I bought 3 weeks ago (see my new member intro post) has those hoses disconnected from HVAC heater core (connected together with "U" hose, union fittings and clamps). I'm in easternmost AZ at 7.4k' elev and this TJ (unlike my JK Rubicon as primary grocery-getter) will be dedicated for year-round off-pavement trail usage (other than highway pavement sections along the way). More than likely, my core is shot with bypassing being cheapest "fix" back then. I might try backflushing the core with mild garden hose pressure to test for leaks inside the cabin but unsure that would be definitive vs with hot engine coolant flowing. Easy enough to test with fresh heater hose connected but I'd prefer to avoid hot coolant steam and vapors in the process of finding out...
 
Novak Conversions Jeep Wrangler TJ engine mounts