Heater Hose Quick Disconnect to Barbed Fitting and Hose Clamp Swap/Fix

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454cid

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Wow a parts store with a machine shop? I don't think we've had one here for at least a decade or more.
 

90halfton

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How ****** can an OEM-style fitting be, if it entered service 18 years ago, and still looks perfect enough to re-use on a fresh engine?

At least you had enough sense to get a restriction installed. I hope it's restricted enough--smaller than the ID of 1/4" pipe.
The bushing Id was equal to the fitting. I say ****** fitting because it is an oring fitting that is always the first thing to start leaking. And I'm one of the lucky few to have screwed one out without it breaking. A brass or ss Male adapter will still be mint when the whole rest of the truck rusts into a pile. Maybe inferior fitting would be a better term than ****** fitting.
 

L337

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i convert to barb fittings on any gmt400 i own or work on. if you are still driving with the original, i highly recommend replacing on your time before it decides on it's own to need to be replaced. your choice on what you decide to replace with. i like how the barb and hose conversion is very affordable. the price on replacing that oem hose is ridiculous.

When they break unexpectedly, it is a big mess and will leave you with coolant everywhere . if you are lucky and they start to show weakness, they will leak coolant on to the intake, boiling and cause steam and foggy windshields. They could cause your coil and/or distributor to start having issues with the humidity in the engine bay.


i had a few break on me when removing. there is a special tool designed just for this job to assist with removing the broken pieces baked on to the intake. just fill the hole with a rag when using the tool and chisling away the pieces. vacuum as you remove the pieces and create dust.

Heater hose coupler remover
https://www.autozone.com/test-scan-.../lisle-heater-hose-coupler-remover/222528_0_0
 
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Abram Turley

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Hey guys, long time forum guest viewer for help and information, new member. My goal is for this post to be helpful enough to be a sticky.

Very simple fix, the annoying plastic quick disconnect that is well known to cause anti-freeze leaks where the heater hose connects into the intake manifold. The problem I found when researching a permanent fix, is that no one gave enough full information or pictures to help a common folk out. So I'm doing that here!
:cheers:

We'll start with parts needed to remove the quick disconnect fitting entirely and replace it with one you don't have to replace yearly. (Note: I'm doing this on my '97 5.7 vortec which has the fitting on the front passenger side of the intake, but I believe all obs have this fitting and the TBI was on the rear of the intake)

All that is needed is the barbed fitting, and 1/2"-1[SUP]1[/SUP]/[SUB]4[/SUB]" hose clamps. For the barbed fitting, any 5/8" I.D. barb to 1/2" MIP/NPT thread will work. I got a brass barbed fitting from Lowes (P/N: LFA-493) and hose clamps from Autozone. (When all was said and done, the I.D. of my heater hose was actually 3/4" but Lowes didn't carry a 3/4" barb to 1/2" NPT, however you can find them online. The 5/8" I.D. barb did work fine just required tight clamps)

On to the pictures!

Only parts bought (less than $10 total):

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Here's what the quick disconnect and fitting look like (forgive my phone's camera, not sure what happened here):

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Before removing the old fitting, I would highly recommend spraying it with some penetrating fluid, I used PB blaster. Be very careful, it's known to break off easy. The socket/wrench size of the fitting is 1[SUP]1[/SUP]/[SUB]16[/SUB]", I used a 3/4" drive ratchet with a deepwell socket and it did me fine, no breaking off:

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I wrapped the threads generously with teflon tape on the new barb fitting. Here it is compared to old fitting:

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There are a few ways to go about the heater hose itself. You could buy another one and keep the stock with the aluminum crimped end. Myself, I found the easiest/cheapest way was just to cut the hose right before the aluminum crimp. This way I can just attach the hose straight to barb and clamp it. Simple. I used sheet metal scissors, easy:

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Here is the new barbed fitting screwed in. Very tight and sealed with teflon tape. I would also be careful here if you go with brass, and not screw it in too tight. This particular fitting had a 13/16" hex, and I used a spark plug deep well socket with a 1/2" drive ratchet:

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I put a generous amount of hi-temp red silicon around the barb (be careful not to put inside hose, you don't want silicon blocking your coolant flow). The 5/8" barb was just a little bit too small inside the heater hose, but with the silicon and the two clamps very tight, it was fine. If I redid this or this is your first time, try to find a 3/4" barb to 1/2" NPT for a perfect fit of the hose. I then wrapped most of the heater hose with some conduit (my hose ended up being a little closer to headers). Here is the finished result:

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From the top:

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And finally, here's the old crappy design that I had so many leaks from removed:

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It's been about a week now, and not a single drop of anti-freeze from the new fitting.

Wonderful forum! Hope this helps some peeps and guests! :cheers:
I am glad I seen this forum post. Good job man. Been working on my 91' GMC truck a lot lately and this helped. I am grateful.
 
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