OEM-type metal lines from trans up to maybe 14-18" from trans cooler mounted on radiator
Ends of metal lines flared/barbed
Trans cooler fluid line hookups are NPT fittings w/ barbed ends
Rubber line supplied w/ trans cooler (Is this considered "high pressure"?)
Lines attached on both ends w/ screw-type hose clamps

NHRA rule book says the trans lines must be metal or "high pressure" type; doesn't specify attachment mechanism

It was never questioned in the past, but I wanted to ask anyway. Oh, mid-10 sec car, FWIW. Thx

If you want yo can change over to braided at the ends of the steel lines then that will give you some
flex and vibration resistance ... use compression fittings on the steel

I’ve seen enough carnage from leaking oil/fluid getting on the tires.

I don’t care what anyone says, manufacturer or not, I would never use any rubber in cooler lines.

Spend some time bending a nice set of lines and use flare fittings and never worry. Just put a wrench on each fitting once in a while to make sure they are tight.

Would it pass tech around here? Yessir, no problem.

If it were me, I'd run it from trans to cooler completely in -6 AN braided line. I did that to my car years ago and it made things much easier. Not having to deal with the hard lines around headers, starter, crossmember, shifter linkage, etc.

The OP setup would pass tech - use hose for ATF.
Just check the hoses before a race, and route them so they're unlikely to dump fluid anywhere near a tire.
I prefer as much hard line for fluids as possible, for a few reasons.
Hoses help dampen vibrations, and much of the time make servicing easier.

I have my cooler mounted under the floorboard and that is exactly how it has been plumbed since 1995. I have replaced the rubber hoses a couple times as preventative maintenace, but to tell you the truth I have been to a lot of tracks and no tech guy has ever even looked at my trans cooler.

No more than six inches of rubber hose in total - I thought was the general tech rule - if it were mine I would use braded instead of that may-pop hose they supply in the kits

No one has ever checked my car. The only things I have been checked for is belts and helmet.
My cooler is mounted under the trunk and I ran -6 PTFE hose. Was not expensive when I did it a few years ago. $50-60 maybe?

Nobody has ever said anything about trans lines that I know of in tech.

Back in the day when I ran 11s and 12s I ran some steel line rubber hose double clamped sketchy stuff but eventually I switched to all braided.

I have to laugh at a few on here.. they all talk safety but to do a job right they will blow it off... or they
say.. next time.. even if they have never been checked on it

Agree. Bad enough to oil the track and pi$$ off their fellow competitors. Worst case they crash their car or it goes up in flames.

Our mopar race has been called the “oil dry nationals” for years by some of the Chevy and ford guys. Most of it is deserved. I still get a kick out of selling old school Hemi guys running flex hoses on their radiators.

Sure, rubber fuel line and worm clamps on non flared, cut off tubing is a bad plan...but modern high pressure push lock flexible hose is no joke. I've been using it on an efi system in street car heat since 2009 to connect the hardline to the fuel rails for example.

That's the direction I've decided to go. Need to see what fittings I have on hand, plus don't believe there's enough -6 line left to do the job.

Not I. I went with-20 AN upper and lower radiator hoses on my build. One of my buddies, crossed the centerline and slapped the opposite wall one time all because of a $1.19 radiator hose clamp let loose on his BBC race car.

Very nice.

If you rely on the tech guy at your local track for guidance on building your car, you are doing it wrong. Passing tech, even by the book tech, is a minimum requirement. There's always a better, safer way.


High pressure hose made for trans cooler applications is a minimum.


If you are using clamps like this...




instead of like this, you are asking for trouble.




Everything I've done for a long time now is AN type hoses and fittings including coolers with provisions for those style connections. I've seen too many messes from doing it the other way.

I used to tell Elmer his Mopar meet was his track's annual rust proofing treatment.

IMO whether it woudl pass or not is questionable. At Capitol and Masin Dixon probably never be an issue no matter what was used. Question is are you comfortable with this set up? IMO use better materials just for peace of mind. You can make steel line easy enough to go to the converter with many options. B nuts and sleeves to flexible braided line, bend the steel line to fit the cooler, simply use braided line end to end. But what ever you do use a trans cooler that has actually fittings or provisions for them. not one that has hose barbs on it......

I would highly recommend Teflon (Aeroquip TFE style) hose and fittings for that application. Trans fluid is nasty and the rubber/stainless braid stuff will degrade over time.

Steel tube can be flared and assembled with nut/sleeve type fasteners. We've done that with 5/16" line using -5 AN stuff. 3/8" goes to -6.

Here’s a sample of what is out there and boy is it nice to work with.

https://www.summitracing.com/parts/add-23-1501

Quick update that I ordered the necessary fittings and PTFE-lined hose to replace the current rubber trans lines.

Good choice
I use PTFE lined hose on all my fuel and oil lines no matter the application, works good, last a long time

Russel and Areoquip love hearing you guys wanting to use their products. Over kill for inadequate mechanics imo

i had one aftermarket #6AN non PTFE lined hose leak on my old stocker after one years use
You get to decide what you want to use, just like I do.
Buy it once and don't worry or loose the shop with all the cars and parts in it due to a leaky, CHEAP fuel line:potentially starting a fire in it

I'm sure Autozone loves hearing from the guys who buy their high end race car components from them too.

Racing flex exhaust pipe, Dayblowna AFBs, Stpm, 3/4 cams and many more. Had a friend who worked a parts store back in the day told me he heard this stuff everyday, a running joke.

Iirc this guy learned about leaking tranny lines….

And he’s not the only one. We have a couple of screw hose clamp guys at keystone that have held up a days racing on many occasions. They have 100.00 for weed but not 100.00 for safe leak free transmission lines.

You'll have to excuse me for having a reaction to your statement above. Oh, and I purchased Vibrant Performance, Fragola and Summit brand hardware for this upgrade.

IMO Fragola is the best stuff out there, but that opinion is like asking who's got the best converter. As for the other comment you do what you like with your car, if cheap hose and hose clamps make you feel all warm a cuddly by all means go that way. I dont use PTFE hose personally but just my choice, just like hose clamp guy makes his.

It’s not cheapy, it’s knowing how to install the most simple thing on any car. If you can’t get a hose clamp on right get out of the kitchen

Hope you are not referring to me Mr P.

Only thing not braided on my car are the rad hoses.

Thanks for the tips. I'm pretty new at this.

Just a little fuel line fire. Stuff happens

I remember NHRA saying 6.0 inch long max on all flexible hoses, tranny and fuel.
I haven't race a NHRA legal class car other than a S/P 7:50 certified car, no rubber or neoprene hose lines on it

That is true of auto parts store rubber crap and hose clamps. The real stuff from any of the manufacturers, using the correct hardware, is good to go for the whole car. SS braid, Aeroquip Startlite, Fragola Nylon Braid, etc.




Fragola is nice stuff, and I believe all or mostly made at their place in Connecticut.

Their nylon braid hose has a single SS braid in it, where the AQP Startlite Nomex braid hose does not. The Fragola is slightly heavier, but both products are substantially lighter than traditional SS braid hose. Also the Fragola hard parts are not quite finished as nice as the Aeroquip stuff...but they also don't cost as much. And the Fragola catalog has a lot more odd and unusual parts that can be helpful.

I use both, but never mix hose and ends between manufacturers. The stuff is different enough that it won't work.

Like I said its like asking whos converter is best...Yes Fragola products are 100% USA made..NO reason for me to try anything else..

As for the clamp guy, I spent all my military career in the USAF. Doing wait for it HYDRAULICS on fighter aircraft. Ask me how many hose clamps we used?

Wovn pushlock is very good hose...But does not use a hoseclamp

You got any tricks you want to share on installing that type of push on hose
I can never get the hose flush with the fittings

They say to dunk it in very hot water to soften it up some. Been a long time since I've fooled with it, and then it was very little.

Someone makes a spiffy tool to put them together too.

I used Aeroquip black pushlock on my car. No clamps, No issues. In the assembly plant there was many miles of blue pushlock but their standard procedure had double eared Oetiker clamps on every fitting. Insurance I guess.

Mine was (actually is) metal hard lines out of the trans, to about 18" or so away from b&m super cooler, formed a bubble at the end of each line to create a barb, hose clamped reinforced rubber trans cooler hose, to NPT barb fittings on the cooler, clamped there too. I never had any problems with it. The few tech people that wanted the hood open were all fixated on the fuel lines and the battery which was never moved to the back.

It's been fine since around 2002/2004 or whatever year it was I did it, but looks like I will have a chance to do it again soon b/c of the rebuild, and will come up with a better arrangement.

This is the way I do it - set the fitting/hose end into aluminum vice jaws and lube/grease the barb that goes into the hose. (I've used Russell hose assembly lube but a thin film of regular grease should be OK). Use a heat gun on the hose material and once it's hot enough push it on to the barb. Gotta work quick though, the material cools quickly and then it can be tough to get it on all the way. Be smart about it, don't cook the hose, use the low setting on the gun and move it around. Hot water does not work as well as the gun, I tried it. I've done it with the heat gun many times over the years, no leaks. Before I used the gun, I researched whether direct heat would have a negative effect on the material (I use Aeroquip hose) but it's good to 300º, I'm not heating it up that high. Water boils at 212º...

If you're going to do a lot of plumbing, might want to invest in this thing.

Expensive tool.

No tricks cab just small amount of lube, we actually use a dedicated hose assemble lube but any lite oil woudl work, even WD could work, you could warm the hose up with hot water bath or a heat gun but so far I have not needed to but we rarely use the stuff unless for customer.

I've been using the Fragola black hose with PTFE and their other liner, I would like see the hose push all the way on each fitting up to the sealing ring (thingy) so it looks better
I do have the Koul assembly blocks for stainless covered hoses and they work great

I was going to buy a Koul tool set originally, until I saw that it doesn't work w/ the PTFE-lined hose setup. Then I saw about an equal number of people saying their PTFE fittings installed w/o issue vs those saying they weren't able to get 'em in and/or they were a major PITA. I was still good w/ the idea of the hose upgrade, so my solution was to measure the original rubber hoses lengths and buy two pre-assembled PTFE-type hoses in the next length up from them.

That's my setup now, other than my trans-spec rubber hoses are closer to 36" long. Never had issues, but gonna upgrade for peace of mind.

In a pinch spit works better than nothing. I've done it that way more than once. Silicone spray works better

Heck in the steel mill we’ve used Goop hand cleaner when we were on breakdowns.

After I discovered Swagelok / Ridgid roller benders and Mastercool / SURR hydraulic flaring tools there's nothing else I'd ever use. It's an investment in tools but I've never regretted using nice tools. Spent 24years making brake, fuel, trans lines with screw type flare tools and dreading it. These tools make it fun.

https://www.amazon.com/MASTERCOOL-72475-PRC-Universal-Hydraulic-Flaring/dp/B01NCYKQSN

https://www.amazon.com/3M-Auto-Parts-PFT409-Fittings/dp/B0792KXDP9/ref=sr_1_7?keywords=sur%26r+flaring+tool&qid=1659050950&sprefix=sur%26r+fla%2Caps%2C129&sr=8-7

https://www.amazon.com/Handheld-Straightener-Portable-Universal-Straightening/dp/B09ZQY6RG9/ref=sr_1_5?keywords=3%2F8+tube+straightener&qid=1659051025&sprefix=3%2F8+tube+s%2Caps%2C151&sr=8-5

https://www.amazon.com/S-U-R-BREZ400-Roll-Brake-Tubing/dp/B008BRHCG4/ref=sr_1_1?crid=19FDDXRDQU7RO&keywords=3%2F8+sur%26r&qid=1659051051&sprefix=3%2F8+sur%26r%2Caps%2C123&sr=8-1

Learn to use these tools and you wont need any rubber in a trans line. On a fuel line the only flexible line would jump from the frame to the engine.

I fixed your links. Leave off everything after the ?

Flare Tool
https://www.amazon.com/3M-Auto-Parts-PFT409-Fittings/dp/B0792KXDP9/ref=sr_1_7?

Tube Straightener
https://www.amazon.com/Handheld-Str...-Straightening/dp/B09ZQY6RG9/ref=sr_1_5?

Tubing Roll
https://www.amazon.com/S-U-R-BREZ400-Roll-Brake-Tubing/dp/B008BRHCG4/ref=sr_1_1?

I have this flare lapping tool, and it is awesome to not have leaky flares
https://koultools.com/product-category/hard-line-sealing-tools/

That NiCu tubing is butter soft and easy to bend. The bad part is, it's butter soft and easy to bend. Has no rigidity and won't hold it's shape, or it's straightness.

I don't want to use clamps every 6 inches, or have stuff look like limp spaghetti and/or get knocked out of shape easily I've been using the steel Bundy-Flex stuff forever. Roll it out, straighten it. Use good benders, Holds it's shape when you bend it up.

Thanks! Not sure what I keep doing wrong?

You have to edit the link after you paste it. Get rid of the green text. It's kind of slow going on a phone since you will have to backspace to erase it all

https://www.amazon.com/3M-Auto-Parts-PFT409-Fittings/dp/B0792KXDP9/ref=sr_1_7?keywords=sur%26r+flaring+tool&qid=1659050950&sprefix=sur%26r+fla%2Caps%2C129&sr=8-7

Wow. The color coder broke the string, learned something new here. Anyway, hope this helps

3/16 line is definitely soft but I've not had issues with it losing shape. 1/4 5/16 and 3/8 are plenty stiff.
I'm not sure what costs more, fancy braided line or good flaring tools and benders.

Thank you! Took me a minute but that finally makes sense.