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How to work out braided brake line length
Slimy38 - 12/10/20 at 09:36 PM

What's the normal process for working out brake lines? I'm not doing anything clever, the kunifer will end in the small tabs as described in the Haynes manual, then off to MX5 calipers. I was thinking 'length of string' approach, making sure I can pin it to the wishbone but leave enough for suspension travel and steering? Is it that simple?


907 - 13/10/20 at 01:39 AM

String is a bit floppy so I used a 1.6 TIG rod.

Don't suppose you have this so straighten out a wire coat hanger.

When wheels are straight make a big curve then make sure that when on full lock either way they still fit.



Paul G

p..s. Don't leave the wife's best dress chucked across the bed.


Mr Whippy - 13/10/20 at 05:39 AM

A bit of rubber hose would be easier, push it over some old hose fittings


rusty nuts - 13/10/20 at 06:58 AM

I often use a MIG liner when fitting metal brake pipes, especially if they need rerouting , to work out the length and route needed. Something similar might work for flexi hose?


Slimy38 - 13/10/20 at 08:05 AM

quote:
Originally posted by Mr Whippy
A bit of rubber hose would be easier, push it over some old hose fittings


quote:
Originally posted by rusty nuts
I often use a MIG liner when fitting metal brake pipes, especially if they need rerouting , to work out the length and route needed. Something similar might work for flexi hose?


That sounds like a perfect combination, I'm sure I have a few feet of liner left over from the last replacement and I have hose all over the place from the donor.

Thanks everyone for the replies, that's really useful.


obuckle - 13/10/20 at 09:14 AM

We usually recommend something which is flexible, but has some stiffness & will follow the path you want, washer tubing, thin hose or electrical cable will all usually do the job. Don't forget to allow for lock to lock & full bump/droop on the suspension, always better to be a fraction long than a fraction short!


coyoteboy - 13/10/20 at 02:13 PM

Also don't forget that braided hose does not twist.

Recently dealt with a braided hose manufacturer who had placed brackets on their product that forced the hose to twist to be installed (imagine the banjo bolt reaching its home 90 degrees out of alignment).

It's bloody hard to twist a small section as you're loading the braiding up, and it eventually fails spectacularly (I found evidence of other users who had had this fail and cause blow-outs of the hose).

So whatever you use, ensure it flows naturally and you don't have to twist the bugger to install it, only bend.

[Edited on 13/10/20 by coyoteboy]


Slimy38 - 13/10/20 at 03:32 PM

quote:
Originally posted by coyoteboy
Also don't forget that braided hose does not twist.

Recently dealt with a braided hose manufacturer who had placed brackets on their product that forced the hose to twist to be installed (imagine the banjo bolt reaching its home 90 degrees out of alignment).

It's bloody hard to twist a small section as you're loading the braiding up, and it eventually fails spectacularly (I found evidence of other users who had had this fail and cause blow-outs of the hose).

So whatever you use, ensure it flows naturally and you don't have to twist the bugger to install it, only bend.

[Edited on 13/10/20 by coyoteboy]


Good advice, I'm trying to understand how I can avoid that? If I understand the fitting correctly, the hose will go into the caliper first and be tightened up. Then it will be fixed at the appropriate points until it gets to the fixing plate. I'll then push it through and lock it with one of those U spring washers. Then the rigid pipe will be screwed to it. I think that should avoid twisting as the won't be a need to align either end.


Slimy38 - 13/10/20 at 03:34 PM

quote:
Originally posted by obuckle
We usually recommend something which is flexible, but has some stiffness & will follow the path you want, washer tubing, thin hose or electrical cable will all usually do the job. Don't forget to allow for lock to lock & full bump/droop on the suspension, always better to be a fraction long than a fraction short!


Oddly enough it'll be you guys I'm more than likely going to come to!


steve m - 13/10/20 at 06:02 PM

I made all my hoses, and the braided ones, and have done for years
all i ever used was a tape measure, and always made the pipes at least two inchs to long, as you can always lose it in a bend etc
Too short, and yoiur stuffed

steve


obuckle - 14/10/20 at 01:55 AM

quote:
Originally posted by Slimy38
quote:
Originally posted by obuckle
We usually recommend something which is flexible, but has some stiffness & will follow the path you want, washer tubing, thin hose or electrical cable will all usually do the job. Don't forget to allow for lock to lock & full bump/droop on the suspension, always better to be a fraction long than a fraction short!


Oddly enough it'll be you guys I'm more than likely going to come to!


I will look out for your order.

In regards to what people are saying about the hoses twisting and union orientation, with my lines it is possible to rotate the unions such at the banjos by holding the ferrule with pliers and using a solid rod, such as a thick screwdriver, in the banjo eye to turn it to the orientation needed so the hose can go exactly where you intent it to