Topic: Has anyone used nylon brake lines?

Our car has brake lines (the hard lines) that have been through 22 hard New England winters and look real sketchy. I'm considering running all new nylon brake lines instead of dealing with replacing the rusty lines. I'm looking at this as an alternative to bending and fishing all new hard lines through out the car. The nylon lines look like they can be run in 15 minutes tops.  Anyone use these on anything before? I can imagine they might be spongy, but that's just me imagining.

http://www.allstarperformance.com/pr... … amp;add=no
http://www.speedwaymotors.com/Lightweig … ,1993.html

30 entries since 2009
#39 & #53 Overengineer'd Racing - Wilton, NH
http://www.facebook.com/nhlemons

Re: Has anyone used nylon brake lines?

Very very very bad idea. Every time you hit the brake pedal the hose will try to straighten out and will cause a very soft brake pedal. The maximin length of hose you should run to each wheel is the fronts can go as long as 18 inches each side but must be anchored in the center 12 inches with no anchor and same goes for lines in the rear.

I know it is hard but use steel line.


Pendejo

Re: Has anyone used nylon brake lines?

If Pendejo says it's a bad idea... ITS A VERY BAD IDEA.

Sons of STIG
Judge Jonny, "So, what's the next formerly thought to be immune from winning that will steal the nickels?An MR2? A Fierro (ha ha ha)? A Datsun/Nissan Z? A Camaro?"

Re: Has anyone used nylon brake lines?

Also as a FYI .... brake pressures can get up to around 2000psi and the temps can get 400+, so yeah, nylon is not a good idea.

Re: Has anyone used nylon brake lines?

Thanks for the replys, I'll just scratch that whole nylon brake line thing from my list.  No point in swapping sketchy old brake lines for sketchy new brake lines.

30 entries since 2009
#39 & #53 Overengineer'd Racing - Wilton, NH
http://www.facebook.com/nhlemons

Re: Has anyone used nylon brake lines?

n0m4d wrote:

Thanks for the replys, I'll just scratch that whole nylon brake line thing from my list.  No point in swapping sketchy old brake lines for sketchy new brake lines.

Universal stainless steels can be found for under $100... worth the investment with steel hard-lines running the body length...

Sons of STIG
Judge Jonny, "So, what's the next formerly thought to be immune from winning that will steal the nickels?An MR2? A Fierro (ha ha ha)? A Datsun/Nissan Z? A Camaro?"

Re: Has anyone used nylon brake lines?

Other than corrosion resistance, is there a benefit to stainless over std steel lines?

30 entries since 2009
#39 & #53 Overengineer'd Racing - Wilton, NH
http://www.facebook.com/nhlemons

Re: Has anyone used nylon brake lines?

n0m4d wrote:

Other than corrosion resistance, is there a benefit to stainless over std steel lines?

Never underestimate the PAH! factor.

"Real ZomBees prefer Bacon"
IOE(x2) MGB/SAAB 96, Judge's Choice, Class C Win, & 2011 Hooniverse Car of the Year!
MRolla, Stick Figure/Animal House, Free Range MR2, SAAB Sonett, "The Death Flip"
2008 Exoskeleton Jag Fiasco, Concours d Lemons - Rue Britannia, worse British car.

9 (edited by TheHeckler 2010-05-06 02:36 PM)

Re: Has anyone used nylon brake lines?

Doug I wrote:

Also as a FYI .... brake pressures can get up to around 2000psi and the temps can get 400+, so yeah, nylon is not a good idea.

Although they might is certain circumstances get that high many lightweight racing master cylinders specify 1500 PSI as the max design pressure for the system.  These are primarily used on 2 master setups.

It's easy to calculate your line pressure max:  ( panic stop may go much higher, depends on driver leg strength )

Pressure = foot pressure * pedal ratio / ( (Master piston dia/2)^2 *3.14159 )

or with normal parts and a single 7/8" master simple or duplex like factory street

line pressure   = 200lbs * 6 / ((7/8 / 2)^2 * pi )

1996 PSI = 1200 lbs / 0.601 in^2  Pretty close to your 2000 PSI level.

With dual masters and bias bar centered divide by 2 for 998 PSI per circuit.


Clamp force at the wheel is similarly easy:

use only one side's pistons ( double sided brake calipers push against each other )

clamp force = line pressure * total piston area
= 1996 * (area of 2 pistons * 2" dia)
= 1996 * 2 * 1^2 * 3.14159
12541 pounds = 1996 P/in^2 * 6.28 in^2

So those big new mustang front calipers squeeze the rotors with 6 tons of force at 200 pounds of pedal pressure...  No wonder they flex a bit

How much brake torque will that generate?

11" mustang rotors, 5" effective radius Moderate performance pads 0.5 COF

brake torque = Clamp force * effective rotor radius * Coefficient of friction
2612 Ft Lbs = 31352 Inch Lbs = 12541 * 5" * 0.5

Our tires are 26" dia so how much, assuming perfect traction, decellerative force could one wheel produce.

force = 2612 ft/lbs / (13"/12"/ft) per rotor side
force = 2411 pounds per pad = 4822 per wheel
2 wheels * 4822 pounds of braking force at 200 pounds pedal pressure from the fronts only.

That's with moderate street pads.  Full race pads have a COF closer to 0.7, soft street pads more like 0.39.

When they get hot and or glazed the street pads COF goes down, race pads should stay stable.

El Capitan de los Bastardos De Lemons
1993 Linco Mark Ate
1957 Renault Dauphine
Driver with LemonSpeed's V6 Mustang

Re: Has anyone used nylon brake lines?

n0m4d wrote:

Other than corrosion resistance, is there a benefit to stainless over std steel lines?

Don't undersell the importance of the corrosion resistance. Not from corrosion from the outside, but from the brake fluid itself. That stuff is incredibly corrosive.

Pat Mulry, TARP Racing #67

Mandatory disclaimer: all opinions expressed are mine alone & not those of 24HOL, its mgmt, sponsors, etc.

11 (edited by Spinnetti 2010-05-03 08:56 AM)

Re: Has anyone used nylon brake lines?

This is getting kinda comical. Physics answers and bling-bling?

A coil of steel brakeline is all of like $20 and will outlast the car by a lot, even in new england. Run new stuff, and get a flairing tool for the ends. You can bend the lines with your fingers (or use a $2 hand bender) - just follow the stock routing and use the stock brackets. Stock rubber lines for the flexy bits are ok, or spend the $100 for goodrich stainless stuff. Everything else is just confusion IMO. After all, you aren't designing a new car, you are just replacing rusty lines!

"Don't mess with Lexas!" LS400. We survived another one! See website link for build details.
Maker of the "unofficial Lemons fish!" - If you ask nice, I'll likely give you one at the track.

12 (edited by TheHeckler 2010-05-03 09:00 AM)

Re: Has anyone used nylon brake lines?

http://video.adultswim.com/robot-chicke … brake-pads

El Capitan de los Bastardos De Lemons
1993 Linco Mark Ate
1957 Renault Dauphine
Driver with LemonSpeed's V6 Mustang

Re: Has anyone used nylon brake lines?

Thank you.  This was my plan originally, I was just curious about the use of nylon lines as an alternative.  For the 4 to 8 days of driving this car has left on this planet in makes no sense to me to invest in stainless, unless there was a performance difference I am unaware of. 

Now, the way the floorboards currently look, the Flintstone braking system is a real possibility.

Anyway, thanks for the opinions/info everyone.

Spinnetti wrote:

This is getting kinda comical. Physics answers and bling-bling?

A coil of steel brakeline is all of like $20 and will outlast the car by a lot, even in new england. Run new stuff, and get a flairing tool for the ends. You can bend the lines with your fingers (or use a $2 hand bender) - just follow the stock routing and use the stock brackets. Stock rubber lines for the flexy bits are ok, or spend the $100 for goodrich stainless stuff. Everything else is just confusion IMO. After all, you aren't designing a new car, you are just replacing rusty lines!

30 entries since 2009
#39 & #53 Overengineer'd Racing - Wilton, NH
http://www.facebook.com/nhlemons

Re: Has anyone used nylon brake lines?

TheHeckler wrote:
Doug I wrote:

Also as a FYI .... brake pressures can get up to around 2000psi and the temps can get 400+, so yeah, nylon is not a good idea.

Although they might is certain circumstances get that high many lightweight racing master cylinders specify 1500 PSI as the max design pressure for the system.  These are primarily used on 2 master setups.

It's easy to calculate your line pressure max:  ( panic stop may go much higher, depends on driver leg strength )

Pressure = foot pressure * pedal ratio / ( (Master piston dia/2)^2 *3.14159 )

or with normal parts and a single 7/8" master simple or duplex like factory street

line pressure   = 200lbs * 6 / ((7/8 / 2)^2 * pi )

1996 PSI = 1200 lbs / 0.601 in^2  Pretty close to your 2000 PSI level.

With dual masters and bias bar centered divide by 2 for 998 PSI per circuit.


Clamp force at the wheel is similarly easy:

use only one side's pistons ( double sided brake calipers push against each other )

clamp force = line pressure * total piston area
= 1996 * (area of 2 pistons * 2" dia)
= 1996 * 2 * 1^2 * 3.14159
12541 pounds = 1996 P/in^2 * 6.28 in^2

So those big new mustang front calipers squeeze the rotors with 6 tons of force at 200 pounds of pedal pressure...  No wonder they flex a bit

How much brake torque will that generate?

11" mustang rotors, 5" effective radius Moderate performance pads 0.5 COF

brake torque = Clamp force * effective rotor radius * Coefficient of friction
2612 Ft Lbs = 31352 Inch Lbs = 12541 * 5" * 0.5

Our tires are 26" dia so how much, assuming perfect traction, decellerative force could one wheel produce.

force = 2612 ft/lbs / (13"/12"/ft)
force = 2411 pounds per wheel
2 wheels, 4822 pounds of braking force at 200 pounds pedal pressure from the fronts only.

That's with moderate street pads.  Full race pads have a COF closer to 0.7, soft street pads more like 0.39.

When they get hot and or glazed the street pads COF goes down, race pads should stay stable.

I love everything about this post.  Someone out there cares enough about n0m4d (whose handle is suspiciously similar to a banned member...) to actually bust out the math.

Now for my $0.02 - brakes are good.  Better breaks are better.  While I'm not advocating stainless steal, the idea of relying on nylon while facing the tirewall at the end of the hella-fast straightaway isn't my idea of fun.

But it sounds like you already came to that conclusion.

I'm the doctor who is a wife. Which makes the grease hard to explain to my patients... www.tetanusneon.com.

Re: Has anyone used nylon brake lines?

I'm sorry if I stirred up trouble, I'm just piecing together a crap can on a shoestring budget like everyone else.  I was told about the lines by a driver on my team, couldn't find any info, asked here, got an answer and am very appreciative for the answer.  I thought it was kind of a legit question, but perhaps not.

30 entries since 2009
#39 & #53 Overengineer'd Racing - Wilton, NH
http://www.facebook.com/nhlemons

Re: Has anyone used nylon brake lines?

n0m4d wrote:

I'm sorry if I stirred up trouble, I'm just piecing together a crap can on a shoestring budget like everyone else.  I was told about the lines by a driver on my team, couldn't find any info, asked here, got an answer and am very appreciative for the answer.  I thought it was kind of a legit question, but perhaps not.

No, it's a completely legit question!  Jeez!

I'm the doctor who is a wife. Which makes the grease hard to explain to my patients... www.tetanusneon.com.

Re: Has anyone used nylon brake lines?

I am often referred to as suspicious however, so you were right on there :-).

30 entries since 2009
#39 & #53 Overengineer'd Racing - Wilton, NH
http://www.facebook.com/nhlemons

Re: Has anyone used nylon brake lines?

There's not one person on this forum that at one point had a question about their car, but was worried it was dumb or unreasonable. I personally am glad you asked the question, which means you really care that stopping is just as important in racing as is speed. I would much rather see you out there with the best your team can afford and also feel comfortable with, than having you T-Bone me in a corner cause your brakes failed. I hope you got the right answer you needed.

Team: V-Ram/Altamont Team: Knights of the Round Track/Reno/Buttonwillow/Thunderhill Team: Death Mobile/Sears 2010/Thunderhill/ChumpCar  Spokane/ MSR Houston/Buttonwillow/Sears. MRolla Project /Reno
http://stickfigureracing.blogspot.com/

Re: Has anyone used nylon brake lines?

Our rustbuckets (2 were combined into 1) had not one good brake line between them.  So all new brake lines were run using the ezi-bend type of line.  Got it at the local carquest.  The fancy name for it is cunifer (google it), but it is coming down in price and availability is becoming common now.  Stuff is corrosion resistant, plenty strong enough for brake pressure, super easy to hand bend, easy to get a good flare.

I recommend it for anything less than a full on restoration.

Jim C.
If God meant for us to race, we'd all have baggy Nomex skin.
08TMS.09NL.10GM, SP, NL.11SP, NL.12SP, VIR, NL.13GM, NJ.14NJ, VIR, WGI.15AB.16GM.17NCM.18GM.19...

Re: Has anyone used nylon brake lines?

Drove a dune buggy once that had nylon lines.  First hard stop and they ruptured. 

There's a real-world lesson for you.  I wouldn't trust them.

Re: Has anyone used nylon brake lines?

Lesse... $24-55 for a six foot stick of stainless and you never have to worry again... OR... you can go cheaper and have a potential brake failure... sure standard steel will save you money now... but why not just shell out the extra money for piece of mind and one thing you'll never have to worry about?

Sons of STIG
Judge Jonny, "So, what's the next formerly thought to be immune from winning that will steal the nickels?An MR2? A Fierro (ha ha ha)? A Datsun/Nissan Z? A Camaro?"