Slimy38
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| posted on 8/1/26 at 08:05 AM |
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Brake line opinions
I have a feeling I know what's coming but I thought I'd put it out there anyway. The rear brakes are set up in such a way that the flexi
hose and the handbrake cable are touching. I couldn't easily figure out a way of putting them in their own space without them being able to
contact each other, so I 3D printed a clamp to actually hold them together.
[img]https://blogger.googleusercontent.com/img/a/AVvXsEiNFSCItPA_fOzQcA604XpyjQpj7dmeqSV9zlKwtWyoDfk2KyrsoGT2BEopRJ0hwWeUzpStMm-Vn-L-cY5tPvMkvA3_FWXJ4
YSR0PNHAe9RxaH_HPCSygyeyT0t3fnmSitYdEwWEchhybxDIBj0-0X_CmGh9ZRpnt_As11D2Q7lCqKp_5YZ3oP_lt2HfpY[/img]
(hmm, the img tag doesn't appear to be working, here's a link to the
Brake line clamp )
They definitely don't chafe anymore, and at no point in the wheel travel do they touch anything else. I have tried different orientations, and
the only other routing that seems to work leaves the flexi hose incredibly close to the wheel. One alternative is to clip the flexi hose to the upper
wishbone but I've asked about that before and that is considered bad form. The handbrake cables cannot move, as you can imagine they exit from
the caliper in one direction and need a smooth transition back to the chassis.
Given the clamp doesn't allow movement through it and prevents the brakes from rubbing, is this a reasonable solution or do I need to go back and
revisit the flexi positioning again?
[Edited on 8/1/26 by Slimy38]
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JAG
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| posted on 8/1/26 at 09:17 AM |
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I'd be happy with that solution.
It's not ideal and I'd be keeping an eye on it...
BUT it prevents relative movement (between the handbrake cable and brake hose) and thereby prevents chaffing. So I'd leave that as is 
Justin
Who is this super hero? Sarge? ...No.
Rosemary, the telephone operator? ...No.
Penry, the mild-mannered janitor? ...Could be!
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Slimy38
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| posted on 8/1/26 at 10:02 AM |
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quote:
Originally posted by JAG
I'd be happy with that solution.
It's not ideal and I'd be keeping an eye on it...
BUT it prevents relative movement (between the handbrake cable and brake hose) and thereby prevents chaffing. So I'd leave that as is
Aye, it's the relative movement bit that took me down this path. Thanks for your view, it's appreciated.
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nick205
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| posted on 8/1/26 at 10:40 AM |
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I'm not an IVA examiner, but have to agree with JAG.
It's preventing movement / chaffing between hose / cable.
If the IVA OK's it then I'd keep a regular eye on it (each drive) to make sure all is secure with no leaks.
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Slimy38
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| posted on 8/1/26 at 10:45 AM |
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quote:
Originally posted by nick205
I'm not an IVA examiner, but have to agree with JAG.
It's preventing movement / chaffing between hose / cable.
If the IVA OK's it then I'd keep a regular eye on it (each drive) to make sure all is secure with no leaks.
That's the thing, I'm revisiting this because my IVA is due early February and I'm wondering whether I need to come up with another
solution before then.
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nick205
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| posted on 8/1/26 at 11:06 AM |
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Do you have a copy of the IVA manual and what is specified in the braking section?
As a possible solution, could you:
1. Extend your hard brake pipe further along the chassis
2. Start the flexi-hose from an alternative location and avoid the handbrake cable
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Slimy38
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| posted on 8/1/26 at 11:28 AM |
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quote:
Originally posted by nick205
Do you have a copy of the IVA manual and what is specified in the braking section?
As a possible solution, could you:
1. Extend your hard brake pipe further along the chassis
2. Start the flexi-hose from an alternative location and avoid the handbrake cable
I think moving the hard brake pipe wouldn't help, but an alternate location might. There's a lot of moving metal in the back to deal with,
all compounded by me running the brakes 'backwards' to accommodate the handbrake and suspension.
I'll have to see what options are available then possibly get some new flexis made to suit. I was thinking about new flexis with a right angle
banjo so it comes straight out from the caliper, but then I have wishbones and driveshafts to avoid.
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Slimy38
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| posted on 8/1/26 at 11:36 AM |
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I can see a couple of specific points in the IVA where this might come into play;
A hydraulic and vacuum component mounting/bracket must be secure to the vehicle structure or other components
If this means the line itself then it's not secure to the vehicle structure, but it is secure to other components.
A brake pipe or hose must be adequately clipped or otherwise supported.
My interpretation is that the hose is 'otherwise supported'.
That's for the hydraulic side of things, then there is this for the handbrake cable;
A parking brake lever, actuating linkage, cable or associated component mounting / bracket must be secure to the vehicle structure
Given the handbrake cable is secured at the same points as it would have been on the MX5, I think I'm covered there.
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nick205
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| posted on 8/1/26 at 11:49 AM |
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SVA for my (pre IVA) MK Indy.
Hard brake pipes from master cylinder, P clipped along chassis to inner wishbone pivots. Brackets to convert to flexis out to callipers/drums.
The flexis weren't supported on the run out to the callipers/drums. Just made sure that they didn't come into contact with anything on
suspension/steering travel.
No issue/comment at the SVA test.
However, the IVA test/rules may well be different. I did mine a long time ago.
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gremlin1234
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| posted on 8/1/26 at 12:20 PM |
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my own observations,
I think what you have should be ok, as it addresses chaffing, however, the flexy ought to have stress relief where attached.
I think a better solution would be a hard pipe from the calliper/cylinder & mounted on the backplate, then giving a cleaner run for the flexy bit
of the piping.
and yes, that would, make it even more of a nightmare to bleed!
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nick205
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| posted on 8/1/26 at 12:38 PM |
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gremlin1234 may have a point there. I ran some hard pipe from the wheel cylinders of my rear drums out to where I wanted the flexis.
 
Rescued attachment fuel tank.JPG
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Slimy38
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| posted on 8/1/26 at 01:32 PM |
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quote:
Originally posted by gremlin1234
my own observations,
I think what you have should be ok, as it addresses chaffing, however, the flexy ought to have stress relief where attached.
I think a better solution would be a hard pipe from the calliper/cylinder & mounted on the backplate, then giving a cleaner run for the flexy bit
of the piping.
and yes, that would, make it even more of a nightmare to bleed!
LOL, I already have a nightmare bleeding because they're upside down!!
It's discs on the back here though, I'm using MX5 parts so it's a sliding caliper. Even if the caliper wasn't able to move
I'd have nothing to fix the solid pipe to on the upright.
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nick205
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| posted on 8/1/26 at 03:00 PM |
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No problem - I didn't have anything to fix to on the MK Indy chassis or rear upright either. I made small brackets from Ally strip and rivetted
them to the chassis and upright for that purpose.
See red circled items...
 
brake-brackets-nick205
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Slimy38
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| posted on 8/1/26 at 03:14 PM |
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Ah, clever stuff! The chassis bracket makes sense, I added brackets early on in the chassis build so they were welded on. I think if I do have to
reroute the hard line or flexi then I'll follow your lead and rivet some aluminium.
Thanks for highlighting the points on the photo, it's appreciated.
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nick205
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| posted on 8/1/26 at 04:40 PM |
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Happy to try and help - the SVA/IVA is a hurdle for sure. We all need to pass it and for our cars to be safe!
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coyoteboy
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| posted on 10/1/26 at 07:51 PM |
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Not sure why clippign the flexi to the wishbone would be considered bad form. So long as you have enough free play to not have it pull or kink.
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Slimy38
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| posted on 10/1/26 at 11:06 PM |
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quote:
Originally posted by coyoteboy
Not sure why clippign the flexi to the wishbone would be considered bad form. So long as you have enough free play to not have it pull or kink.
It was a question I asked many moons ago when I first started putting things together, the general view was the flexi should be in free air. I'm
not 100% sure either but I guess I'll stick with what I have for now. I might go back to the clipping option if it ends up being preferred.
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gremlin1234
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| posted on 11/1/26 at 04:16 PM |
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quote:
Originally posted by Slimy38
It was a question I asked many moons ago when I first started putting things together, the general view was the flexi should be in free air. I'm
not 100% sure either but I guess I'll stick with what I have for now. I might go back to the clipping option if it ends up being preferred.
simply, hard lines should be where there is no movement, and flexy where there is.
this also applies to house mains wiring, cable in the wall, flex from the outlets
and also in network wiring -single strand fixed to sockets, and drop leads to equipment.
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