Heater core hoses
 

I have a 1992 Chevy Blazer (full-size, K5, 1500) with an unmodified 5.7L 350 with over 206K on it. ( still runs like a champ )

This is a new buy for me and to insure all the coolant and heater hoses are 100% for the coming weather I'm replacing them and the coolant.

I have the new upper and lower radiator hoses. The heater hoses which do not look bad but must be replaced for sake of doing the job right.

The hose that goes from the radiator heater hose fitting to the right hose fitting of the heater core appears to be a standard 3/4 inch hose ( cut to length ). The left side of the heater core to the top of the engine ( intake manifold near the distributor) has what appears to be a crimped hose connection ( much like an AC or other high pressure hose ) to aluminum pipe that screws into the intake manifold.

The first hose mentioned I can find anywhere. But the left side hose to crimped connection aluminum pipe to threaded fitting into the intake manifold near the distributor is not in any parts book or even pictured in any service manual I have seen.

Is someone familuar with this part or the place I can get the replacement for this?

You can pull the fitting out of the intake manifold and put a regular 3/4" hose barb fitting in it's place. It'll make life a lot easier than messing around with the OE arrangement. I have never seen these pieces either, but never tried to replace one of them.

Well I have bad news, the danged aluminum hose fitting to the intake manifold broke with the threads thread-locked in the intake manifold. I think someone had a leak before I bought it and thought that a keen way to solve the problem.

Now I have 2 issues what size/thread tap do I use to clean out the bits of aluminum that 7 hours of attempting to use an easy-out and gentle chiseling has left behind?

Also can you point me at a good place to pick up that '3/4" hose barb fitting', as I can't see the threads yet I'm going fishing in the dark.

Thanks again

BTW -- I agree with you about the OE arrangement, this is bad.

ironically this same thing happened to me today... I had just replaced the heater core and all the hoses BUT this one, one look at it and I didnt want to mess with it BUT last night the rubber hose part of this line sprang a leak, so I went to the parts place and got some new line and was going to splice it close to the aluminum. As soon as I released the line from its clamp it came off in my hand, broke clean off at the intake so now I am exactly where you are, trying to figure out how to get the crap aluminum out of the intake w/o screwing it up further, I too tried chipping away at it in hopes that it would break and I could remove the pieces but no such luck... I tihnk the lock tight is a OEM feature, the only place I can find the exact line is Chevy, I am opting for the old school nipple and rubber line replacement from tractor supply. Let me know if you get any good advice or figure it out.

speed
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well my official GM FITTING REMOVAL tool is a piece of ****e ! all it has managed to do is strip it out the inside of the fitting more to the point that the tool doesnt have anything more to grab onto... guess its time to tap it out... I would like to shoot the guy who designed this little item...

I've ground with the screw extractor and chipped mine away so I can at least get a tap in there. Now if I can find the 1/2" tap to clean out the threads. Spoke to a machanic that has worked on these 350's and has had simular issues. and all I need to do is find the tap and I should be good. He says plumbing supply centers will carry it, now to find one that actually does -- Furguson isn't one :-(

I have found the old school fitting at pep-boys where it's not the barb but it has the half bubble on the end so when you put the hose on all you need is a clamp. 4.99 -- part number eludes me at current if you want it I'm sure I can dig in the trash and find it.

Sorry --SPEED-- I know your pain.

you, and --SPEED-- can use the 3/4" NPT barb fitting that swartlkk mentioned.
i had to do this on my '92 Jimmy when i rebuilt the 4.3 in it. you need to get the proper tap drill size for a 3/4 NPT thread, and a 3/4 NPT tap, (of course). when you drill (and tap) anything that's still attached to your engine, coat the drill and tap with some grease, this will "hold" the cuttings, and keep them from falling into the engine.

****sorry guys, i screwed up!**** it's not 3/4" NPT, it's a 1/2" NPT thread, which is what is used on 3/4" pipe. i know it sounds pretty f**ked up, but that's how it is.


here's a link to a site that shows all of the sizes for pipe and NPT sizes:
http://www.engineeringtoolbox.com/np...ads-d_750.html
if you go down to the graph (1 screen page down) you'll see the chart. look for the 1/2" size under "Pipe Sizes (inches)". it show the OD of the pipe and the tap drill size. hope this helps you guys.
sorry about the wrong size up there.

Nope makes sense -- found a parts shop in Norther VA ( where I live ) that carries something simular

Vermont American 1/2-14Npt Tap Part Number: 20354



http://www.amazon.com/Vermont-Americ...4422832&sr=1-7

Glad I have a local parts shop and didn't have to use the big boys for this ( Advance/autozone/napa...etc)

hmmm... I lost a thread I posted... I bought a "fitting removal tool" but it doesnt work, I twisted one extension in two trying to get it out... then it stripped out the inside and wont bite anymore... now Im going thru the taps but now the last one wont grab hold... I too found the nipple at the parts store but I bought the quick connect just in case, I also called GM for the replacement hose for the quick connect... $42.00

Nope, you didn't lose it. It's right there, where I combined with the post you made just before it. If you want to add something to a post before anybody has answered, use the 'edit' button rather than do consecutive posts. :icon_wink:

that would be the one i was refering to. just remember to apply the grease to the threads before you tap it. hope you this goes well for you. good luck.