Heater hose replacement

[Juliet P.]

My '70 heater hose has been chafing on the AC compressor (incorrectly routed hose) and needs replacement soon. (350/300 Auto, AC car)







The judging manual mentions molded hose ends which *may* have the GM logo on them. Are these hoses still available through GM or am I relegated to the repro catalog houses... of they even sell a "correct" hose? It's sometimes hard to tell from descriptions/photos if you don't know exactly what you're looking for, and the catalog interpretation of correct isn't necessarily "correct" in the NCRS sense.

The dimensions listed in the JM refers (for example, there are several different ones needed) to a 1-1/4 inch tower (Wittek Mfg. Co.) clamps on the 3/4 inch hose. Is this the tower height across the max clamp measurement or what? Also, is there a good source for tower clamps with the appropriate date, galvanization / zinc plating? Is there a reason to NOT use the tower clamps (other than they're a PITA to remove later)? Is the tower part supposed to be pointing straight up when clamped?

Also, this hose attaches to a vacuum thing (which controls the flow to the heater core, downstream of it). Mine is just hanging out in the breeze. Is this correct or should it be bracketed to something? Any other details I should be concerned with from a judging point of view while I'm monkeying around in this part of the engine compartment?

Thanks, Juliet

[Terry M.]

Re: Heater hose replacement

Juliet,

I can not tell you much about heater hoses for AC cars, but the size of tower clamps is stamped on the clamp, along with the manufacturers name and the other information listed in the JM. The small block heater hose clamp section does not address all the clamps that might be used on an AC car because we had no good original examples to determine clamp usage. It is possible that some of the clamps used on a C60 equipped car might be other than tower clamps.

Check the AIM - C60 section for the mounting of the vacuum controlled heater shut off valve. I am not sure there is a good illustration there, but might be.

Tower clamps are easy to remove/reuse. Trick is to use nut driver to loosen the screw as much as you can - back it all the way up as far as it will go without backing all the way out of the nut - then hit the top of the nut driver with your hand, hard. This forces the nut that the screw threads into down and opens the clamp so you can slide the clamp up the hose and reuse the clamp.

No the clamps do not all face up, in fact they face whatever position is convenient for the assembler to tighten. Someone with an unmolested C60 car will have to provide the details.

Terry

[Robert C.]

Re: Heater hose replacement

Juliet, Great pictures! but , where's the engine paint? There used to be a woman in Florida that sold original heater hoses. I believe her name is Nelson. Somebody will remember. Otherwise it's repro time. Repro's on heater hoses aren't to bad compared to vacuum colored stripe hoses.


Texas Chapter NCRS

[Joe L.]

Re: Heater hose replacement

Juliet----

GM never catalogued a SERVICE replacement specialized heater hose for your application. However, I believe that either a GM #482424 or, possibly, a GM #3992177 will work. The problem is that these parts GM list for $29.46 and $25.90, respectively, so you might not want to be taking a "stab in the dark". Otherwise, a reproduction is probably the way to go. Without offending anyone, I would have to say that, in my opinion, Dr. Rebuild has among the best reproduction hoses available.

As far as the Wittek tower style clamps are concerned, I am not certain that all of the heater hose clamp positions on a 70 with A/C used the tower style clamps. I believe that some, or possibly even all, of the positions may have used screw type clamps. However, this is not an area of particular expertise for me, so take this "with a grain of salt". I can tell you this for CERTAIN, though: my original owner, September 1969 built small block w/o A/C had a mixture of screw-type and tower style heater hose clamps originally installed. In any event, as far as obtaining original style tower clamps, Dr. Rebuild has a very large inventory of original Wittek clamps. These clamps were actually manufactured in many different configurations over the years that Wittek was in business, so I couldn't say that Dr. Rebuild would have the EXACT original clamps available. However, his are ORIGINAL Wittek clamps as Dr. Rebuild was a Wittek clamp distributor when they were in business. I believe that he purchased all of their remaining stock after they went out of business and he still draws on that stock.

[David Van Weele]

Re: Heater hose replacement

Linda Nelson is out of the hose business. I was one of the first to restamp this hose from stock that I bought from GM in the early 80's. We had a stamping machine and dies made up and just rolled the correct logo etc on 50 lengths of hose. I sold my interest in the company to Linda (Z06 Productions) some time ago. She did the hose, belts and many small parts for a number of years. A few years ago she sold the company to Corvette Central. If they are still doing the hoses I do not know.