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

[jaydee1445]

This is what I mean about quality clamps, it is the type you find on German cars. They won't cut into your hoses. I got mine from Summit Racing also on Amazon

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[highwaystar]

I see your manifold fitting is made of steel.
I replaced my QD with a brass fitting years ago. Integrity of brass vs steel in this application?

 

[454cid]

The manifold to core is 3/4 hose is and the NAPA fitting is 5/8. That is why a good worm gear clamp is needed to take up the slack. Many times I‘ve by-passed bad heater cores in vehicles like Cherokee’s were the dash has to come out to replace the core by looping the 3/4 hose over to the 5/8 fitting. Haven’t had a failure yet. YMMV.

Yeah, I'm definetly not doing that. Bypassing a leaking heater core to get home is one thing, running like that all the time is asking for trouble, in my opinion. That yellow restrictor looks promising, Though.

 

[jaydee1445]

Found ACDelco fitting 15-33220 GM12597484 it is 3/4 x1/2 NPT and has the same 3/8" restriction. I'm going to replace NAPA fitting with it.
Update original post with pics

 

[GoToGuy]

That's the fitting i used in stainless. Taking a 3/4 id hose and squeezing it down on a 5/8 fitting is a problem waiting to happen at the worst possible time. Here it comes " oh no way, i did that 2 lifetimes ago it works". You wanna take shortcuts go for it. Do it right the first time. Good luck.

 

[eran tomer]

i put a new heater core after previous owner disconnected it.
luckily i read this thread, i wasn't aware of the restricting thing.
a new Dorman quick fitting was garbage, so i'm using this fitting that had been already on the back of the manifold, appliyng some Permatex Aviation on the threads.
went to the machinist and had made this reducer, it will be stuck into the heater pipe. then a 3/4 rubber hose and that's it.
permatex aviation on

 

[Stringer]

Remove the MAP sensor and bracket and losten the harness retaining nut to get a straight shot with the drill.
Half of the broken off end of the QD was rotted away so I went straight to the step bit.

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One of the old timer ticks I was taught was coat drills and taps with wheel bearing grease to trap the chips and keep them out of the engine. The first step cut right through with drill on forward.

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I tired reversing the drill for the next step and it caught the remaining threads and twisted them out in chunks.

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im confused. do i have to drill into the engine in order to get 15-33220 to fit in?? or can i just remove the factory fitting and screw this new one in??

 

[Schurkey]

IF (big IF) you can unscrew the old one, you can screw the new one in. The problem is the original one is sometimes so rotted that they break off in the manifold. Then the remnants have to be "extracted".

 

[Stringer]

IF (big IF) you can unscrew the old one, you can screw the new one in. The problem is the original one is sometimes so rotted that they break off in the manifold. Then the remnants have to be "extracted".

awesome thanks! mine looks rough but im hoping ill get it out in one piece. ill hit it up with pb for several days before pulling, 15-33220 will take about a week to arrive anyhow.

 

[Schurkey]

ill hit it up with pb for several days before pulling

That'll make a nice stain on the concrete where it all drips off.

Penetrating oil is useless on pipe thread. Pipe thread seals by deforming the threads, making an air-tight seal. The penetrating oil can't get in to do any good. If it could, coolant would be leaking out.