Visit The Dirt Forum for More Information

Author Topic:   Nylon Brake Lines
blanep
Member
posted September 29, 2002 07:18 AM
Some time back I asked a couple times about nylon (plastic) brake lines. It seemed the only negative responses I read about them were from people who had never tried them. Sleepy Gomez gave me the confidence to try them though and so a few weeks back I did. For $25-$30 and about 2 hours of my time (would take someone with even a small amount of mechanical skills less time I would assume) I had the whole car re-plumbed and am loving it. I did run some parts of the line through some cheapie fuel hose just for some added protection and I did use braided lines to the calipers rather than running to them direct. With all the fittings I used (ran 2 prop valves and 1 shut-off so that added several fittings) I only had 2 leaks, but they simply needed tightened a bit as I had heard from a couple of folks not to tighten them too tight.

Anyways, maybe you'd hate them and maybe you'd have problems with them, but I just wanted to post my experience with them so far so that others who are comtemplating trying them out will have another opinion to base their decision of off.

outlawstock17
Member
posted September 29, 2002 10:37 AM
in my opinion, i'd NEVER use plastic brake lines. they're not worth the weight advantage and they're just not safe.

picture this scenario......you're engine just blew up and caught fire....you're brake lines melted and you can't stop the car. if and when my engine blows and catches fire, the first thing i want to do is clobber the brakes and get the heck out of that thing as fast as possible.

hopefully the above situation would never happen, but i'm not willing to take that chance. if you're willing to take that chance and that scenario takes place, may God be with you.


madmodshoe
Member
posted September 29, 2002 04:19 PM
If your car caught on fire and burned hot enough to melt the plastic brake lines, then the fire would only boil the brake fluid in your steel brake lines therby causing you to have no brakes! It is really a matter of personal preference. It is very easy to repair plastic brake line under a yellow flag situation, versus having to double flare steel line. Thoughts of mine!


outlawstock17
Member
posted September 29, 2002 04:38 PM
madmodshoe, i disagree. take a lighter and see how much heat it takes to burn those plastic brake lines. with plastic lines it only has to melt the line in one small spot to kill the brakes. if the heat boils the fluid in that same small spot on a steel line, the brakes will still function, maybe a little spongy. schrapnel from a blown engine or something ran over on the track can cut a plastic brake line a lot easier than a steel line too. i'm taking my chances with steel brake lines. plastic lines just aren't as durable, chances are slim that you'll ever need to repair a steel line under a yellow, under a red or at any other time between races.

i've weighed the pros and cons of plastic vs. steel brake lines and in my opinion, steel wins hands down.

[This message has been edited by outlawstock17 (edited September 29, 2002).]

[This message has been edited by outlawstock17 (edited September 29, 2002).]

blanep
Member
posted September 29, 2002 08:42 PM
Heh, as you see, the people who hate em never have ran em.

Trust me when I say that safety is of great concern for me, heck I'm the one always trying to get you guys to think about and possibly even try some type of head and neck restraint (and I'm not referring to donut collars). I'm NOT wanting to start a flame war here, but since we're doing scenarios then I'll throw my own scenario in that actually happened and isn't just a hypothetical.

Solenoid cap mysteriously breaks and somehow allows the battery cable to flop free and it just happens to flop over against the steel break line and of course it grounds out, burns a nice hole through the steel line and proceeds to spew brake fluid all over the hot headers. Apparently brake fluid is pretty flammable when spewed onto hot headers and a real nice blaze engulfs the engine compartment. Obviously the harder you stomp the brakes the more fluid you spew until there is simply not enough to keep spurting because you have no idea at the time what is causing the inferno to begin with.

Now I am in no way saying that this happening to me made we switch to plastic or anything like that. But I am saying that any freakish deal you can come up with is theorectically possible regardless of what you use. As I stated previously, I did run it through some fuel line just for added protection in certain areas, but I have yet to hear from anyone who has actually had a plastic brake line cut by a rock or other shrapnel and would think that it would have to be a pretty freakish fire to burn through any brake lines before you got it stopped. Besides that, it would have to somehow burn up (or cut with rocks) both the front and rear lines at the same time to cause me not to be able to stop since it's dual master cylinders.

Again, I'm not trying in any way to convince others to use plastic lines because everyone has their own preferences and theories. I just wanted those who are contemplating using them to be able to hear from someone else who has tried them out and what my preliminary reactions to them were.

outlawstock17
Member
posted September 29, 2002 10:28 PM
okay blanep, you're right......any worse case scenario is big trouble.

the battery/solenoid shorting on a brake line is a lot bigger freak accident than a blown engine and fire or schrapnel but we can just agree to disagree and move on. i'll keep my steel lines. i am curious as to why no one else has joined the fray.



ford5
Member
posted September 30, 2002 05:47 AM
we have used plastic lines here for years and never had a bit of trouble, care should be taken as to where they are routed and secured. i for one, will never go back to steel.......my opinion ford5


powerglides
Member
posted September 30, 2002 05:54 AM
Well since I may me the cause of some of this, here goes. I will agree that using steel or plastic lines is a matter of personal preference. Just so we are on the same page, what is plastic brake line? It is a 3/16" od line made of a nylon compound with rated at 2800 psi. It can be kinked at roughly twice the bend radius of steel line. It can be squeezed shut and it will have rebound.

I can't give you specific info on the heat resistance, however I was surprised how long it held up to an acetylene rich flame.

As for toughness, I can only say stand back and throw rocks at both kinds and see which one lasts longer.

I make some mods to a brass fitting which lets me run the plastic all the way to the caliper. Calipers get hot. I have run this setup on my I-Stock, on mini-stocks and on my sprint car. I'm sure some one will have a failure sometime but I never have had a problem.

I first became aware of the plastic lines somewhere in the early '70s racing go karts with hydraulic brakes. I reasoned hydraulic pressure was hydraulic pressure. I used this line on a stock car sometime in the late '70s, before kits were available. Been using it ever since.

So my friends, take your choice. There are advantages and disadvantages to both. We could make similar arguments about creamy versus crunchy peanut butter. Personally I like #%&*%^^*. SLEEPY



blanep
Member
posted October 01, 2002 07:58 AM
Creamy


kong
Member
posted October 08, 2002 01:08 PM
hey sleepy, do any of the winston cup teams use nylon brake line? if not, why?


Geffy95x
Member
posted October 08, 2002 02:53 PM
Good point Outlaw!!!!!!


SLEEPY GOMEZ
Member
posted October 08, 2002 04:30 PM
NASCAR WON'T ALLOW IT,JUST LIKE THEY WON'T ALLOW ALUMINUM BODY PANELS OR BODIES THE SHAPE OF STOCK OR ....... THE LIST GOES ON. I SURE AM GLAD WE DON'T RACE $16 MILLION CARS ON OUR DIRT TRACKS. HECK THEY PROBABLY DON'T EVEN LIKE PEANUT BUTTER. SLEEPY


2nd2none
Member
posted October 08, 2002 06:00 PM
I dont like peanut butter


outlawstock17
Member
posted October 08, 2002 06:46 PM
sleepy, i hope that you didn't take offense. i value your opinions. i was just pointing out that nylon brake is not allowed in winston cup. i don't know the specifics on why it isn't allowed, but i'd be willing to bet it falls under safety.

the cost difference between steel and nylon is minimal. the weight difference is negligible.

we can agree to disagree and move on. you guys know my take on it and now i'll let it rest.

Geffy95x
Member
posted October 08, 2002 06:57 PM
I'm allergic to peanuts.


ryan
Member
posted October 08, 2002 08:10 PM
I use steel lines but I wouldn't be opposed to the plastic lines if I ever bought a car that had them. I don't think I would put nylon lines on my own car.
p.s. CRUNCHY ALL THE WAY


SLEEPY GOMEZ
Member
posted October 08, 2002 09:24 PM
Hey guys, no offense taken. I think this forum is a great way to discuss all these things. I know Im glad to be able to listen to everyone else's opinion.

Creamy - 10 points
crunchy - 15 points
chew the peanuts in the shell
making your own - YOU WIN

SLEEPY

istock59
Member
posted October 09, 2002 07:34 AM
I'm considering giving them a try on my new car. But I'd like to keep using braided from the caliper to the frame. Do you have to buy a special adapter to go from the nylon to a AN4 fitting?


loojack
Member
posted October 09, 2002 03:06 PM
I'm planning on using nylon lines on the car I'm building now.. The nylon lines come with 1/8"pipe fittings,which racing brake componets use. I assume(O BOY!)someone makes a 1/8"pipe thread to AN-4 adapter. Great thread guys!
Forgot to add my vote for peanuts in the shell!!

[This message has been edited by loojack (edited October 09, 2002).]

blanep
Member
posted October 09, 2002 07:03 PM
I used steel braided line between the front calipers and the plastic line simply because I already had them on hand. I can't remember where I got the fittings that went from the platic line to the an4 braided line though. It was either midwest motorsports, speedway or at the local parts store. Looking at the 50th anniversary speedway catalog (the big purple one) simply because it is laying here, they have them listed as gauge fittings on page 245.


SLEEPY GOMEZ
Member
posted October 09, 2002 08:22 PM
This is hard for me to do now that I have peanut butter all over the keyboard. If you want to run plastic lines to the calipers do this. Drill a hole opposite the bleeder ***** . It should be about .340". Use a 1/8" pipe tap to thread this hole into the caliper. Now, the 1/8" pipe fittings used for the lines will thread right in. Last, swap sides with the calipers. The plastic line fitting is now on top. Crack the nut gently to bleed the brakes. SLEEPY


loojack
Member
posted October 10, 2002 03:34 PM
Sleepy, I guess I'm missing something,where should the .340 go? Do I block off the banjo bolt hole with a bolt, or is this opposite the bleeder *****? Thanks, Sleepy and I'm looking forward to your next article!
loojack


malibuchevy2
Member
posted October 10, 2002 09:50 PM
i have ran plastic brake lines on my hobby stock car and had no trouble with them this year they are pretty durable and the brakes work good


istock59
Member
posted October 11, 2002 11:32 AM
Hey Sleepy, I like that idea, but that brake mod isn't exactly legal...


SLEEPY GOMEZ
Member
posted October 11, 2002 09:38 PM
Ikay, I got a little ahead of myself, sorry. Drilling and tapping the caliper was doing it the hard way and also not IMCA legal. My current method is to get a 7/16" brass manifold nut (fits 5/8 wrench). These nuts are about double the length of a standard nut. Drill and tap the side of the 7/16 nut for 1/8" pipe thread. Use the .340" drill. Drill the i.d. of the 7/16 nut, I think with the same .340 drill for cleanup. Use the stock banjo mounting bolt on your new banjo fitting. Leave out the copper gasket, the brass will seal.
SLEEPY


WesternAuto17
Member
posted October 29, 2002 12:29 PM
Used em. Hated em.

Maybe it was something else, but they always felt spongy. All steel, all real for me.

Back to the Archives