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

[Roger D.]

I've called several of the online and local parts suppliers and am having trouble finding the correct O.D. transmission cooling line hoses for my 1972 350/200 Auto. I want to be able to use the existing (original) hose clamps. Every transmission hose I have found is too small (but not all parts suppliers I contacted wanted to take the time to measure the O.D. for me). Anyone know where to get the correct O.D. hoses so I can use my clamps? I measured the O.D. to be .708 inch (5/16 in. hose).

Regards,
Roger

[Joe L.]

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

I've called several of the online and local parts suppliers and am having trouble finding the correct O.D. transmission cooling line hoses for my 1972 350/200 Auto. I want to be able to use the existing (original) hose clamps. Every transmission hose I have found is too small (but not all parts suppliers I contacted wanted to take the time to measure the O.D. for me). Anyone know where to get the correct O.D. hoses so I can use my clamps? I measured the O.D. to be .708 inch (5/16 in. hose).

Regards,
Roger

Roger-----


I'd try calling Dr. Rebuild. They have reproduction hoses for the trans cooler line application as well as NOS Wittek hose clamps.

[Greg L.]

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

I bought the cooler hose kit from Paragon and it has the correct O.D. size but when I tried to install it on the tubes I saw that the I.D. was way too small(looks like about 1/4" I.D.) and there was no way it was going to fit so off to my junk repop box it went.

Maybe I shouldn't have done this but I know it has been done before.... I used fuel hose.

I fits perfect and has the fiber braiding for strength. I don't know what PSI the fuel hose or the "proper" transmission hoses is rated for but from what I can remember the return from the cooler in the transmission dumps straight into the pan so there should never be any great amount of pressure to worry about. I'm not saying to use fuel hose but rather, I have used it and have known others to use it on their vehicals and I haven't heard of any problems.

I hope others will chime in on this if what I've done is a big no-no.

[Roger D.]

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

Well I don't know about fuel hose as fuel application is generally low pressure/temperature. Also definitely different chemical properties than transmission fluid. Some of the hose I have seen at the local supply houses specifically state on the hose that it is for transmission fluid application. Will be interesting to see what everyone says about that.

[Joe L.]

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

Well I don't know about fuel hose as fuel application is generally low pressure/temperature. Also definitely different chemical properties than transmission fluid. Some of the hose I have seen at the local supply houses specifically state on the hose that it is for transmission fluid application. Will be interesting to see what everyone says about that.

Roger-----


There exists specific hose for use for automatic transmission cooler lines. For the most part, fuel hose is manufactured from the same materials as this hose with respect to inner carrier tube (usually fluroelastomer or nitrile rubber), reinforcment (usually aramid fiber, rayon, or nylon), and outer cover (usually hypalon). However, some lower grade fuel hose might not have the temperature resistance necessary. If one uses fuel hose labeled as "fuel injection hose", this pretty much covers all bases. It will have transmission fluid resistance as well as temperature resistance. In fact, it usually has a HIGHER temperature resistance than automatic transmission cooler hose.

So, why do they have specific automatic transmission cooler hose and why don't they just use "fuel injection hose" for automatic transmission cooler line applications? Very simple. The "fuel injection hose" is much more expensive than automatic transmission cooler hose. So, folks that use a LOT of the automatic transmission cooler hose (like automotive assembly plants and automatic transmission shops) don't want to use "fuel injection hose" as a substitute.

However, for an individual doing one car the cost is no big deal. One problem: the generally standard OD dimension for MODERN 5/16" ID rubber hose, either "fuel injection hose" or "automatic transmission cooler hose" is about 5/8". So, if that OD doesn't suit one, I don't know what to do.

[Roger D.]

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

Thanks Joe. Well I called Dr. Rebuild and they couldn't help me either. I am getting tired of calling around. Maybe I'll take the info you provided and try some industrial hose supply places to see if I can find a hose with O.D. to match my existing. You're right on that O.D. for standard 5/16 hose. I believe all I saw were about 5/8 inch. Seems that surely someone else has run into this problem and can say where they got their replacement hose.

[Jim T.]

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

I did a posting not to long ago on transmission hose for my 70. I changed a rubber transmission line hose going to the radiator on my 70 about 15 years ago. For replacement hose I used the reinforced fuel line hose, not fuel injection hose. Not very long after putting on the new fuel line hose as the replacement hose it bursted while I was driving my 70. The fluid spraying on the exhaust let me know by way of smoke that something was wrong and I was lucky I had only left the house about 5 minutes earlier and the engine was not up to operating temp.

I replaced my transmission line with steel reinforced rubber hose that I bought at a local business that makes hydraulic lines for everything that needs them.

[Roger D.]

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

Hey Jim. I need a hose approx .708 inch O.D. Is that the same as you were able to find? If so then perhaps I will find some hose if I keep looking.

[Jim T.]

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

Roger the hose I bought is 2/16 or 3/16 smaller than 3/4 inch. My replacement hose has Type AT-MSHA 2G-20C- 2250 PSI MAX WP 3/8 stamped on the hose. I got this from the length I did not use.

[Joe L.]

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

I did a posting not to long ago on transmission hose for my 70. I changed a rubber transmission line hose going to the radiator on my 70 about 15 years ago. For replacement hose I used the reinforced fuel line hose, not fuel injection hose. Not very long after putting on the new fuel line hose as the replacement hose it bursted while I was driving my 70. The fluid spraying on the exhaust let me know by way of smoke that something was wrong and I was lucky I had only left the house about 5 minutes earlier and the engine was not up to operating temp.

I replaced my transmission line with steel reinforced rubber hose that I bought at a local business that makes hydraulic lines for everything that needs them.

Jim-----


I expect the problem was that you used conventional fuel line. Most conventional fuel line is only good to about 125 degrees F. The transmission fluid is way hotter than that and will quickly degrade the fuel line. Fuel injection hose is usually good to about 275-300 degrees F.

[Harmon C.]

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

Roger
I used regular gas hose transmission lines on one car and tried to use the original clamps which were the type with the screw on the side. They would not seal tight and always looked wet. The OD must have been larger on the original hose as you pointed out and I didn't know it so in the end I switched to worm clamps before the PV.

[Roger D.]

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

Yea Lyle. That is the same type clamps I have and your situation is exactly what I was concerned about. I will keep looking. Going to Call Bair's this morning to see what they might have.

[Jim T.]

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

Joe my bursted fuel line hose had only been on my 70 for a short time and was really a new installation, not subjected to any lengthy drives more than 10-12 miles at a time. I still have the bursted hose and looked at it again last night when I looked at the length of the steel wire reinforced hydraulic hose I had left over from the installation of new transmission line hose. I kept this piece of fuel line hose because all but the first three inches are usable and is really in like new condition. The hose was on the lower radiator fitting location.
Fuel injection hose on my 85 that is connected to the fuel pump/filler neck assembly was the hardest hose I have ever encountered to remove from a fitting. This was about 10 years ago when I replaced the fuel pump and pulsator. Did not want to split with a knife because it was going to be reused. It was really really tight/sealed to the metal fuel line.

[Richard R.]

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

Several years ago I bought a roll of the correct hose from my local Chevrolet dealer. They would not order less than a 25 foot roll but it was the correct ID and OD. I'm not sure it is still available but it's worth a try.

[Harmon C.]

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

Joe my bursted fuel line hose had only been on my 70 for a short time and was really a new installation, not subjected to any lengthy drives more than 10-12 miles at a time. I still have the bursted hose and looked at it again last night when I looked at the length of the steel wire reinforced hydraulic hose I had left over from the installation of new transmission line hose. I kept this piece of fuel line hose because all but the first three inches are usable and is really in like new condition. The hose was on the lower radiator fitting location.
Fuel injection hose on my 85 that is connected to the fuel pump/filler neck assembly was the hardest hose I have ever encountered to remove from a fitting. This was about 10 years ago when I replaced the fuel pump and pulsator. Did not want to split with a knife because it was going to be reused. It was really really tight/sealed to the metal fuel line.

Interesting that you say only three inches of hose was damaged and the rest was usable. The hoses on my turbo 400 were less than six inches in total length. I have 15,000 miles on the gas hose with no problems and lots of 500 mile runs.