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All round braided brake pipes
Stevie_P - 30/11/15 at 03:50 PM

Toying with the idea of using braided brake pipes throughout.
Anyone done this?
Is this OK for IVA?
I suppose they may produce a slightly more spongy pedal as I assume they'll have more give than copper pipework.

Always happy for comments good or bad.
Cheers
Steve

russbost - 30/11/15 at 04:18 PM

Been done 1000's of times, no problem for IVA provided clipped up every 30cm as usual. There will be no difference in the pedal there is no "give" in a braided hose anymore than in a copper pipe.

Advantages ease of use/fitting & appearance, only downsides are cost & a fractional weight penalty

loggyboy - 30/11/15 at 04:23 PM

quote:
Originally posted by russbost
Been done 1000's of times, no problem for IVA provided clipped up every 30cm as usual. There will be no difference in the pedal there is no "give" in a braided hose anymore than in a copper pipe.

Advantages ease of use/fitting & appearance, only downsides are cost & a fractional weight penalty


Theyre not only downsides the biggest and most important is that when they inevitably start to degrade you cant tell where the problem is or get an idea there is a problem till its too late.
Stick to solid pipe for as much of it as you can!

russbost - 30/11/15 at 04:29 PM

"Inevitably degrade"???? All our lines are from HEL, top quality stainless steel & guaranteed for the life of the vehicle - the only degradation might be some very low grade deterioration of the PVC cover due to UV - the integrity of the lines will not breakdown in the life of any normal vehicle.

I doubt you'll find any copper lines with that guarantee!

Edited to say another advantage is less junctions of pipe to hose, which are always a potential failure/leakage point.

[Edited on 30/11/15 by russbost]

Doctor Derek Doctors - 30/11/15 at 04:37 PM

I used flexi-pipe throughout on my race car, was much simpler to make and route, less potential leak paths and I could remove the brake lines to do chassis work without having to split the system down.

The 'spongy' feel myth is just that, a complete myth.

Its the way I'll be going on future builds.

dinosaurjuice - 30/11/15 at 04:58 PM

I run braided lines on the rocket, I even went to the extreme of each wheel has its own line from the master cylinder to caliper, no tee's or bulkheads etc. It actually worked out cheaper as the extra meters of hose was less than using copper and more fittings/tees. Thoroughly recommended by me

Stevie_P - 30/11/15 at 05:20 PM

I think that's a winner then
Russ, I assume you can supply a 'kit' for use on an MK Indy R?
U2U me a price if you can?
Cheers
Steve

russbost - 30/11/15 at 05:32 PM

quote:
Originally posted by Stevie_P
I think that's a winner then
Russ, I assume you can supply a 'kit' for use on an MK Indy R?
U2U me a price if you can?
Cheers
Steve


I wish it were that simple, unfortunately as people use different master cylinder setups, different calipers etc & each "7" is different, however, assuming you are using even vaguely modern calipers all threads will be m10 x 1.0, (providing they aren't Wilwoods which use 27 x 1/8 NPT!), same for the master cylinders unless you have a dual m/cyl Girling setup which uses imperial threads, most people go for straight swivel males on the caliper end as makes them easier to fit, but obviously you have the option to go for banjo ends if that suits pipe routing better.

Assuming you are going to uses T's use m10 x 1.0 there as well, again straight male swivels unless there is a specific requirement for anything else.

I just need lengths & what ends for each of the pipe runs & whether you want us to supply the T's or you have your own (if your own need to confirm thread) & what colour you want on the hose (no extra charge for any available colour). We always suggest following the line of the hose runs with washer tubing, electrical cable or similar, anything which will realistically follow a similar path.

Just drop me a u2u or email russbost followed by the @googlemail.com when you have lengths etc.

Cheers Russ

Stevie_P - 30/11/15 at 05:38 PM

Of course Russ. Totally forgot that everyone is using different stuff.
I am using Wilwood calipers up front.
Will email you what I've got / want and take it from there.
Cheers
Steve

hizzi - 30/11/15 at 06:39 PM

only thing to beware of with braided lines fuel or brakes is during the build of your car beware if you weld anything that the earth clamp is on the part being welded otherwise the braided hose with become the earth path and melt internally.
wrote off a car a few years ago due to this

coyoteboy - 30/11/15 at 07:00 PM

quote:

"Inevitably degrade"???? All our lines are from HEL, top quality stainless steel & guaranteed for the life of the vehicle - the only degradation might be some very low grade deterioration of the PVC cover due to UV - the integrity of the lines will not breakdown in the life of any normal vehicle.


What's the internal tube made of? Braided isn't as rigid as solid pipe, but you won't notice it in any normal vehicle. I'd be happy using braided throughout except I think I like the neater look of rigid, plus rigid will be lighter.

britishtrident - 30/11/15 at 07:26 PM

A few points.
1)Is braided hose fit for purpose ? Yes.
2) Would it be choice for a road car ? No
3) Would it be the choice for a single seater? Yes
4)Will it have more elastic deformation under pressure than solid pipe ? Yes but it will have only a miniscule effect on pedal travel.
5) What is the best material for road car brake lines? Genuine Kunnifer, nb. Never copper!

I have bad experience with braided brake and fuel hoses.The reasons I try to avoid them (1)The only new flex brake hoses I have ever encountered with manufacturing faults were the braided type. (2) I encountred more than a few fuel hoses on old military vehicles and BMC cars where the metal braiding had caused pin hole punctures in the hose.

russbost - 1/12/15 at 08:14 AM

quote:
Originally posted by coyoteboy
quote:

"Inevitably degrade"???? All our lines are from HEL, top quality stainless steel & guaranteed for the life of the vehicle - the only degradation might be some very low grade deterioration of the PVC cover due to UV - the integrity of the lines will not breakdown in the life of any normal vehicle.


What's the internal tube made of? Braided isn't as rigid as solid pipe, but you won't notice it in any normal vehicle. I'd be happy using braided throughout except I think I like the neater look of rigid, plus rigid will be lighter.


The internal pipe is rigid teflon lined PTFE, the hoses have been tested to 18,000psi in 24hr "whip tests" where the end of the hose is left unattached & allowed to whip around as fluid is forced thro' at 18,000psi (that's something like 20 times+ the highest pressure you're likely to achieve in any normal braking sytem), they have to survive this test to be certified - before anyone says anything daft - this is a one off test that hoses of the same type are subject to, not a test for each hose made!

russbost - 1/12/15 at 08:22 AM

quote:
Originally posted by britishtrident
A few points.
1)Is braided hose fit for purpose ? Yes.
2) Would it be choice for a road car ? No
3) Would it be the choice for a single seater? Yes
4)Will it have more elastic deformation under pressure than solid pipe ? Yes but it will have only a miniscule effect on pedal travel.
5) What is the best material for road car brake lines? Genuine Kunnifer, nb. Never copper!

I have bad experience with braided brake and fuel hoses.The reasons I try to avoid them (1)The only new flex brake hoses I have ever encountered with manufacturing faults were the braided type. (2) I encountred more than a few fuel hoses on old military vehicles and BMC cars where the metal braiding had caused pin hole punctures in the hose.


I'd beg to differ on point 2) choice for a road car - if, by "road car" you mean ordinary tin top, then no I wouldn't ever bother doing the whole car in braided, but it is still a better, more attractive & more durable choice for each corner & sometimes can save considerable time when replacing a metal pipe if the routing of that pipe involves removal of chassis parts as you can fit the braided hose where you wouldn't necessarily fit copper/kunifer

Re 4) I'm not sure if you're right even under laboratory conditions as there is obviously some wall deformation under pressure of kunifer & more so with copper, I've never actually seen a direct comparison, I DO know that when compared with rubber hoses you can actually feel the difference, the braided hose giving a much firmer pedal

re 5) again depends on where the hose is & what it & the vehicle are going to be used for, argument for kunifer over copper it is harder, stiffer & more durable, however copper is FAR easier to work with it is so soft & for any "normal" use if you're going to use hard pipe I would usually use copper over kunifer (depending on exact application)

Horses for courses!

AdamR20 - 1/12/15 at 09:33 AM

My 2p... I have two identical cars (Mk1 MX-5s), both used exclusively on the track. The first has hard lines in the 'normal' locations then stainless flexi hoses from the ends of those to the calipers, and the second car has braided stainless throughout. They both use the same calipers, rotors, pads (brand and model), wheels, tyres and are the same weight and ride height to within a few kg / mm.

Brake feel on the second car is significantly worse than the first one, and the second car requires considerably more brake pressure to lock the wheels. I'm at the point where I am considering 'going backwards' and fitting hard lines to the second car, even though the braided hoses were pretty expensive and much easier to route.

[Edited on 1/12/15 by AdamR20]

Doctor Derek Doctors - 1/12/15 at 09:40 AM

Thats far more likely to be some air in the line or an M/C or Caliper fault. If it's significantly worse then there is something actually wrong.

We used the same braided line to do the high pressure ultra high speed hydraulic controls on the Merc' F1 engines (throttle, wastegate and other special bits), if there was even a tiny amount of 'spongyness' in those lines it would have caused a delay and wouldnt have been used.

AdamR20 - 1/12/15 at 09:48 AM

Interesting. I thought the same, so I have spent some time swapping M/Cs, re-bleeding etc. as I didn't believe the braided lines could be any less stiff, but the only difference I can identity throughout the whole system is the hoses!

Stevie_P - 1/12/15 at 09:48 AM

Seems like I've sparked a bit of a debate here.

I think it's a case of pay your money and take your choice.

Cheers
Steve

russbost - 1/12/15 at 09:54 AM

quote:
Originally posted by AdamR20
My 2p... I have two identical cars (Mk1 MX-5s), both used exclusively on the track. The first has hard lines in the 'normal' locations then stainless flexi hoses from the ends of those to the calipers, and the second car has braided stainless throughout. They both use the same calipers, rotors, pads (brand and model), wheels, tyres and are the same weight and ride height to within a few kg / mm.

Brake feel on the second car is significantly worse than the first one, and the second car requires considerably more brake pressure to lock the wheels. I'm at the point where I am considering 'going backwards' and fitting hard lines to the second car, even though the braided hoses were pretty expensive and much easier to route.

[Edited on 1/12/15 by AdamR20]


I am 100% sure that changing the lines isn't going to improve things unless you have a damaged line ie braid has been damaged allowing the inner line to bulge, or some other issue within the system.

Is it possible that with the routing of the flexies you have introduced a loop or "uphill" section which is trapping air & hence failing to bleed properly? You don't say whose lines you're using but I have never heard of any braided lines giving a softer pedal, there has to be something else going on there.

AdamR20 - 1/12/15 at 10:08 AM

Thought about / investigated the above also... Can't think of anything else it could be. Theory dictates they should be the same but my own findings have been different. I subscribe to both routes in everything I do on a car (theoretical and "actual" ), and usually find they co-incide, which is why I'm confused here!

On a similar note, the brakes perform the same on both cars in terms of which wheel locks first and the overall front to rear bias, both with and without a passenger, so I'm fairly sure there's no air in the system. There is an uphill route which crosses the engine bay to the NSF wheel, but this is the same on the hard lines and is never a problem to bleed through.

The lines were from Rally Design, so hopefully not cheap rubbish.

If I do fond a definitive solution, I'll come back and post it!


[Edited on 1/12/15 by AdamR20]

rodgling - 1/12/15 at 10:18 AM

quote:
Originally posted by AdamR20
Thought about / investigated the above also... Can't think of anything else it could be. Theory dictates they should be the same but my own findings have been different. I subscribe to both routes in everything I do on a car (theoretical and "actual" ), and usually find they co-incide, which is why I'm confused here!

On a similar note, the brakes perform the same on both cars in terms of which wheel locks first and the overall front to rear bias, both with and without a passenger, so I'm fairly sure there's no air in the system. There is an uphill route which crosses the engine bay to the NSF wheel, but this is the same on the hard lines and is never a problem to bleed through.

The lines were from Rally Design, so hopefully not cheap rubbish.

If I do fond a definitive solution, I'll come back and post it!


[Edited on 1/12/15 by AdamR20]


As a simple test, remove the calipers and block off the lines, e.g. with a nut and bolt on a banjo fitting, or a blind hole on a male fitting, and bleed them. Pedal should then feel absolutely rock solid, even with braided lines. If it doesn't, isolate the faulty part by blocking off at different points and eliminating various bits of braided line. If hoses are OK, add the calipers one by one until you find the fault.

AdamR20 - 1/12/15 at 10:32 AM

I like that - simple and methodical (like me). Cheers

Problem now is being arsed to do anything about it, the car goes well despite the 'meh' brakes, and I have a scratch build to be getting on with

[Edited on 1/12/15 by AdamR20]

britishtrident - 1/12/15 at 11:35 AM

Sounds like an caliper problem to me the difference in stiffness between braided and solid pipe work exist but would be a mm or less at the pedal. Likewise unlikely to be caused by an up hill loop as modern small bore systems are unlikely to have trapped air.

With rubber-textile reinforced flexy hoses it is easy to track down a caliper issue much more difficult isolating a wheel with braided because you can't clamp off a hose.

britishtrident - 1/12/15 at 12:30 PM

quote:
Originally posted by AdamR20
I like that - simple and methodical (like me). Cheers

Problem now is being arsed to do anything about it, the car goes well despite the 'meh' brakes, and I have a scratch build to be getting on with

[Edited on 1/12/15 by AdamR20]


Caliper issues tend to get gradually worse as pads wear, it is so gradual the driver mentally adjusts to it without noticing

coyoteboy - 1/12/15 at 06:21 PM

quote:

The internal pipe is rigid teflon lined PTFE, the hoses have been tested to 18,000psi in 24hr "whip tests" where the end of the hose is left unattached & allowed to whip around as fluid is forced thro' at 18,000psi (that's something like 20 times+ the highest pressure you're likely to achieve in any normal braking sytem), they have to survive this test to be certified - before anyone says anything daft - this is a one off test that hoses of the same type are subject to, not a test for each hose made!


Teflon IS PTFE, and it's FAR from rigid. Hence my point. The only thing that makes it more rigid is it's restrained by the braiding, which itself allows some expansion as the braiding tightens against itself (not much, but some). It's better than good old rubber (that's why it's an upgrade to normal cars) but it's NOT better than solid pipe for bulk runs.


quote:

I have bad experience with braided brake and fuel hoses.The reasons I try to avoid them (1)The only new flex brake hoses I have ever encountered with manufacturing faults were the braided type. (2) I encountred more than a few fuel hoses on old military vehicles and BMC cars where the metal braiding had caused pin hole punctures in the hose.



Yep, I've seen several tin-top flexis fail by the braiding parting ways with the end connection and allowing burst of the liner too - that's down to care in fitting and proper design (these were fitted in a twisted position which then repeatedly took the braiding way into high deformation in one direct and back out in the other, fatigue hell.

[Edited on 1/12/15 by coyoteboy]