Antifreeze Leaking Connection On Intake Manifold

[Kens1990K2500]

I used the OEM replacement push-in nipple when I replaced the heater hose, because the metal portion of the hose was badly corroded. No issues removing or installing it. I always prefer OEM parts, if possible.

 

[eran tomer]

I used the same setup but didn’t use a restrictor. My heater still works really well. I’m curious if it improved heat on your setup. Have you ran it both ways? Thanks.

i didn't drive the car with it yet, there is still some job to do. but the heater was disconnected from when i bought it until now so i wouldn't be able to compare.
anyway they say it's meant to prevent the core from blowing out or from making noise, not to improve the heating.

 

[Caman96]

I’ll probably get one of these

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eventually. Last summer I installed a new Acdelco OEM style that so far looks good!

 

[dilerin]

A restrictive nipple has been suggested to be used when replacing the quick connect, see...

Restricted fitting to replace heater QD. Udated Delco fitting 15-33220

There are several threads with the pros and cons to using brass fittings to replace the problematic quick disconnect that tends to leak and break. I'm not going to beat that dead horse but share the restricted fitting i have found. Orginally I used a NAPA fitting but it was 5/8 so I'm going to...

www.gmt400.com

Reportedly the quick connect was restrictive for a reason, and that restriction should be maintained.

"... restrictive for a reason ..." may be true but I worked with engineers for fifty years and know that they utter and design as much nonsense as any man, and much of that nonsense sneaks through many a design review and ends-up in myriad products you buy. So - that said, I replaced the leaking fitting in my '98 with an unrestricted nipple and so far so good. But, full disclosure; if I had it to do over again I would probably use a restricted fitting, depending on cost.
To retain the molded fit I used the original hose. In order to save as much of the molded end as possible I carefully cut off the metal QD fitting with a thin cutoff wheel on a Dremel tool.
For anyone who hasn't done it yet I would recommend a pre-emptive strike, replacing the quick disconnect fitting (an engineering mistake) with a nipple, or even another QD. When the original QD fails, and it will, removing the broken half from the manifold will test your resolve.

 

[1998_K1500_Sub]

"... restrictive for a reason ..." may be true but I worked with engineers for fifty years and know that they utter and design as much nonsense as any man, and much of that nonsense sneaks through many a design review and ends-up in myriad products you buy. So - that said, I replaced the leaking fitting in my '98 with an unrestricted nipple and so far so good. But, full disclosure; if I had it to do over again I would probably use a restricted fitting, depending on cost.

I really wasn't aware of the presence or purpose (alleged or otherwise) of the restriction until having read some of what's been posted here (GMT400), where I take what's been said "on faith". Some of the people here command my respect, they know their subject matter well.

I too have replaced the fitting (1998 Suburban) with... something, I think a brass fitting that I got a hardware store, surely one without a restriction. In my case, my Suburban has dual heaters, so I believe the concern for a restricted fitting may not be relevant... indeed, with dual heaters the extra flow capacity of the heater circuit is possibly better suited without the restriction at the fitting. That said, my guess is all the L31s had the same "restriction" integral to the quick-connect fitting, regardless of dual or single heater application.

To retain the molded fit I used the original hose. In order to save as much of the molded end as possible I carefully cut off the metal QD fitting with a thin cutoff wheel on a Dremel tool.

I did something similar throughout my Suburban, e.g., see my contributions to this thread (below). However in my case I wanted to replace the hose as well, hence my suggestion to use the Gates molded hose on the intake fitting, if desired (bulk hose works fine too, just not as "pretty").

95 Suburban rear heater hose questions

Ok Burb gang, got a question. This weekend I got a hairline crack in one of the plastic heater hose quick disconnects under the hood (where it splits into front/aux heaters, not actually at the heater core), and a pinhole coolant leak. The heater hoses look like they're probably original, so I...

www.gmt400.com

 

[Hamps]

i didn't drive the car with it yet, there is still some job to do. but the heater was disconnected from when i bought it until now so i wouldn't be able to compare.
anyway they say it's meant to prevent the core from blowing out or from making noise, not to improve the heating.

Interesting
Thank you.