Where Do I find the Correct O.D. Trans Cooling hose?

[Jim T.]

Re: Where Do I find the Correct O.D. Trans Cooling hose?

Lyle using an accurate measure of the fuel line bursted end, only ruined the first two inches of the fuel line I used to connect the transmission fluid line to the radiator. This piece of fuel line is 8 3/4 inches long that I cut to replace my original rubber transmission hose, so I have plenty left of usable hose to use to replace the rubber fuel line I use between the fuel filter I installed between my 70's original fuel line that I cut and connected to the dual feed chrome metal fuel line on a Holley double pumper on my ZZ1 crate engine that I installed in my 70.

[Harmon C.]

Re: Where Do I find the Correct O.D. Trans Cooling hose?

The length of the hose must have changed over the years. I never noticed them being that long.

[Roger D.]

Re: Where Do I find the Correct O.D. Trans Cooling hose?

Richard, thanks for the suggestion. I did not even think to call the dealer as they have told me "no" quite frequently when looking for parts for my '72. I will give that a try.

I did find the following and I don't know if it will work.

Goodyear Galaxy SAEJ2064 Type C Class II, 5/16". It is .750 O.D. which is a little larger than the original .708" O.D. It is rated for -40 to 257 degrees F, Max working press 500psi, Min burst press 2000psi.

It's made for automotive A.C. applications to carry refrigerants. Has a synthetic rubber internal layer (polychloroprene) with nylon barrier.

Think that would work? I'm a little concerned about using it as it is specifically manufactured for A.C. application.

[Joe L.]

Re: Where Do I find the Correct O.D. Trans Cooling hose?

Richard, thanks for the suggestion. I did not even think to call the dealer as they have told me "no" quite frequently when looking for parts for my '72. I will give that a try.

I did find the following and I don't know if it will work.

Goodyear Galaxy SAEJ2064 Type C Class II, 5/16". It is .750 O.D. which is a little larger than the original .708" O.D. It is rated for -40 to 257 degrees F, Max working press 500psi, Min burst press 2000psi.

It's made for automotive A.C. applications to carry refrigerants. Has a synthetic rubber internal layer (polychloroprene) with nylon barrier.

Think that would work? I'm a little concerned about using it as it is specifically manufactured for A.C. application.

Roger----


You'll find that most GM dealer parts countermen are going to "look puzzled" if you ask for "special rubber hose" for automatic transmission cooler lines. However, if you provide the part numbers, they should be able to help.

I believe that the hose you seek is one of these part numbers:

GM #9439104

GM #9438315

GM #9439550

The problem is I don't know which one it is and I sort of doubt that your GM dealer will know, either. All of the above are supplied only as 25 foot rolls and are priced at GM list $70.75, $116.25, and $116.60, respectively.

[Roger D.]

Re: Where Do I find the Correct O.D. Trans Cooling hose?

Joe, thanks for that information. I'll check the Chevy dealler with those part numbers. I assume the part number I need is in the AIM. I'll look at mine.

[Joe L.]

Re: Where Do I find the Correct O.D. Trans Cooling hose?

Joe, thanks for that information. I'll check the Chevy dealler with those part numbers. I assume the part number I need is in the AIM. I'll look at mine.

Roger-----


The part number you need IS in the AIM. Unfortunately, that number will do you or your GM dealer no good, at all. In PRODUCTION, the hoses were pre-cut to length, assigned a specific part number, and never available as a SERVICE part through GMSPO.

However, the original part numbers did do ME some good. Using these numbers and some rather obscure references, I was able to track down the current part number for the bulk SERVICE hose used to replace the original PRODUCTION hose. That part number is currently GM #9438373 and it's the direct descendant of the hoses originally used on your car. This means that it's fully GM-approved for use in your application and it meets GM spec 9985393. It's still available in a 25 foot roll for $84.00, GM list.

I don't know what the OD of the hose is. However, this hose is 3/8" ID. Since it's GM's direct descendant of the original hose, I've got to believe that the original hose was 3/8" ID, too. In fact, I always thought that's what these transmission oil cooler lines were and I was a little surprised to see you say that they are 5/16". This would also answer why you found to be too small the OD of the 5/16" ID hose you obtained.

In any event, if you want to go with the 5/16" ID hose (which, right or wrong, is the size I was operating under when I posted my previous responses), then I've confirmed that of the 3 part numbers I mentioned, the one you need is the GM #9438315. It meets the same material specs as the 9438373. However, I still expect that if you go with the 5/16" ID hose, you're still going to end up with too small an OD for your purposes. I think that the possibly incorrect assessment of the ID of the original hose may be the crux of the whole problem here with respect to OD.

[Richard R.]

Re: Where Do I find the Correct O.D. Trans Cooling hose?

Roger I can't comment about the compatibility of the Transmission fluid to the refrigerant but Joe is right on about the 3/8" ID. I went out to my shop and miked the piece I had left over and it Mikes .360 ID and .675 OD. I also noticed it had script which read KV-61-404 3/8 p/s return B11 018. Could this be power steering return hose? Hope this helps

[Joe L.]

Re: Where Do I find the Correct O.D. Trans Cooling hose?

Roger I can't comment about the compatibility of the Transmission fluid to the refrigerant but Joe is right on about the 3/8" ID. I went out to my shop and miked the piece I had left over and it Mikes .360 ID and .675 OD. I also noticed it had script which read KV-61-404 3/8 p/s return B11 018. Could this be power steering return hose? Hope this helps

Richard-----


I believe the GM hose used for the transmission cooler lines is and always was sort of a "multi-purpose" hose. It is rated for use with fuel, oil, and emissions systems. I believe the reference to "power steering return", which is ONE of the approved applications for the hose, is done to identify the hose as a NON-high pressure rated hose. I don't know if original hose was so-imprinted and, I suppose, it would take examination of some known-original hose to determine this. However, whether the original transmission cooler hose was originally imprinted "power steering return", or not, I believe it was the same hose used for power steering return hoses.

[Greg L.]

Re: Where Do I find the Correct O.D. Trans Cooling hose?

How much pressure would you expect to see in these cooler lines anyways?

I'm almost certain that the return passage has no restriction what so ever in the transmission body so to me that means, no restriction = no pressure....just flow. Of course there will be some "resistance" in the cooler and friction in the lines but is it really enough to create any significant back pressure?

[Phil D.]

Re: Where Do I find the Correct O.D. Trans Cooling hose?

I just measured the top hose barb coming out of the radiator on both Roger's 72 and my 69 and both measure 0.313 or 5/16". I can't reach the bottom one easily to measure with my caliper but it looks larger like it might be 3/8". Guess we'll figure it out when we actually get the hoses out, but would have been nice to have the correct replacement hose in stock before we actually remove the old ones.

[Roger D.]

Re: Where Do I find the Correct O.D. Trans Cooling hose?

Hmmm... this is all very interesting and I hate to continue the thread needlessly but I originally assumed the correct size of the hose was 5/16 inch I.D. because I noted it available in that size for '63 to '82 cars from Paragon Corvette Reproductions (click on the following link)...

http://www.corvette-paragon.com/catalog/Product.aspx?id=40E347A0-5209-4C21-A135-F96D89A6729A

[Joel A.]

Re: Where Do I find the Correct O.D. Trans Cooling hose?

Roger, I can check the rolls we have at the shop today, and see what they measure. We get some hose with the auxiliary coolers, as well as hose-on-a-roll for trans coolers.
Regular fuel hose will normally work in a pinch, but it doesn't last...the heat, and the chemicals in the trans fluids these days will eat it up eventually.

I'll see what we have, and let ya know.

btw...have a safe vacation trip!

[Roger D.]

Re: Where Do I find the Correct O.D. Trans Cooling hose?

Thanks Joel. I appreciate it! Yea though not really looking forward to Europe, the wife has been wanting to go her whole life. With all she's been thru the past couple of years I am going to go and at least look like I am enjoying it.