Remove heater hose connection on back of cylinder head

[gambitpaul]

As I am replacing all the cooling system hoses on my '74 tii, I also want to make sure the hose connections are smooth to prevent leaks. So I bought a replacement for the hose nipple on the back of the cylinder head where the hear core return hose attaches. The original design is a two part, reducer and nipple. Newer design is one piece (11121257516)

I got the nipple off, #3 above (11121250746), after a lot of PB Blaster and creative wrenching.

 

 

 

Anyone have some good way to remove the reducer coupling (11121250745) on the back of the cylinder head? It is #5 in the first picture. It does not have any flats to fit a wrench or socket.

Any suggestions would be appreciated.

Paul

 

[Mike Self]

First of all, your '74 has the larger diameter heater hoses that were adapted (IIRC) with the modell 71 cars to allow better coolant flow through the heater core.  And according to the drawing in the parts book, the reducer (part #5 in your illustration above) has a hex head, as do the ones I've seen on cylinder heads.  Perhaps yours has been replaced.  That being said...

 

Why do you need to remove it?  Was it leaking?  are the internal threads that the nipple screws into in bad shape?  This sounds like one of those, "if it ain't broke, don't fix it" situations.  Just screw the new nipple into the old adapter and be done with it. 

 

But if you must...try grabbing it with a small pipe wrench.  That may cause more problems, as you're only gonna get a quarter of the wrench's jaws on the adapter, so there's a good chance it'll slip.  Regardless, you're gonna booger up the edges of the adapter, and you're trying to unscrew steel threads from aluminum.  Dissimilar metals don't play nicely with each other, especially after a 50 year embrace, and if some threads are gonna let go, they'll be the aluminum ones in the head.  Then you really have a problem!  Back to paragraph 2...leave well enough alone unless its so badly rusted it was leaking like a sieve.  But I'll bet it wasn't.

 

mike

[Son of Marty]

I'd say stay with your original reducer it looks fine.

[tzei]

If it aint broken don’t fix it.

 

Pipe wrench or chisel usually does the job. 
 

If #3 is badly corroded, find a replacement or turn new.

[TobyB]

I'm amazed you go that far-  and my 2 cents would be to replace the nipple 

and don't even try to remove the reducer.   Figure out the threads on

the existing nipple, chuck a hunk of 416 stainless rod into the lathe, and cut it to shape.

 

Easy, right?

 

You could also cut the threads off your nipple and braze them onto a new nipple.

 

Or figure out the threads, as above, and hit the internets.  Prosche, in particular, liked doing

things that way, so there are lots of p-car plumbing parts that have fine- thread metric ends.

 

Or, since we're using all that heat now, to get the original reducer out, if you really must,

weld a long, solid bar to it using lots of heat.  Let it cool, and then see if that can get it out.

If not, heat the end again, let it cool, and try again.  Cycling breaks it free, so be patient.

 

As a 'more mature gentleman' I find that I am able to get more things apart than I could in my youth simply because

I keep trying.  Whoever said insanity was trying the same thing again and again and expecting 

a different result obviously never worked on old, rusty machinery.  

 

 

t

[north1602]

Hi

I had the same issue.  It’s very unlikely you will get the reducer out without destroying it. My machine shop tried everything and eventually chiseled it (thankfully no damage to the head).  
 

I couldn’t find a replacement so I took the two pieces to a local machine shop and for $110 cash, they CAD the measurements and cut me one piece part from aluminum.   It was pretty simple for them.  here is a pic.
 

 

[tzei]

Light metal one piece #11121257516

 

From E21/28/30 M10. About ten bucks + shipment.

 

Threads: head M36, nipple M22 x 1,5 (new, big), M18 x ,5 (small, old style).

[gambitpaul]

On 7/26/2024 at 9:24 PM, Mike Self said:

First of all, your '74 has the larger diameter heater hoses that were adapted (IIRC) with the modell 71 cars to allow better coolant flow through the heater core.  And according to the drawing in the parts book, the reducer (part #5 in your illustration above) has a hex head, as do the ones I've seen on cylinder heads.  Perhaps yours has been replaced.  That being said...

 

Why do you need to remove it?  Was it leaking?  are the internal threads that the nipple screws into in bad shape?  This sounds like one of those, "if it ain't broke, don't fix it" situations.  Just screw the new nipple into the old adapter and be done with it. 

 

But if you must...try grabbing it with a small pipe wrench.  That may cause more problems, as you're only gonna get a quarter of the wrench's jaws on the adapter, so there's a good chance it'll slip.  Regardless, you're gonna booger up the edges of the adapter, and you're trying to unscrew steel threads from aluminum.  Dissimilar metals don't play nicely with each other, especially after a 50 year embrace, and if some threads are gonna let go, they'll be the aluminum ones in the head.  Then you really have a problem!  Back to paragraph 2...leave well enough alone unless its so badly rusted it was leaking like a sieve.  But I'll bet it wasn't.

 

mike

Really I wanted to replace the nipple end so that the new hose would have a smooth surface to seal. But the new part I orderedwas one piece with the reducer incorporated. So I initially thought I should remove the reducer. But after inspecting the area I don't think there was any leak from the reducer.

So gonna leave it. I ordered a SS version of the nipple from WN. Although I did toy with  getting a generic nipple from Amazon.

 

Thanks.

[gambitpaul]

20 hours ago, north1602 said:

Hi

I had the same issue.  It’s very unlikely you will get the reducer out without destroying it. My machine shop tried everything and eventually chiseled it (thankfully no damage to the head).  
 

I couldn’t find a replacement so I took the two pieces to a local machine shop and for $110 cash, they CAD the measurements and cut me one piece part from aluminum.   It was pretty simple for them.  here is a pic.
 

 

Yeah my reducer looks like yours, with out the hex flats. I am convinced at this point not to try and remove it.

Thanks

[north1602]

I had to get mine made because the engine head is a 118 (for a 1602) and the reducer piece is 30mm not 36mm.   Nobody makes that aftermarket size.