Braided brake hose query

[hardhatharry]

Where can I get custom length braided brake hose (72cm) with the male ends to go into the brake Girling master cylinder and servo (same fitment as master cylinder) for a spitfire 1500?

[Colin Lindsay]

You can buy it by the metre from Kit Car Suppliers but you'll have to add the ends yourself - something I never tried.

I'd reckon hydraulic hose manufacturers could make one up for you, although you may have to supply the ends for them to crimp on.

[Pete Lewis]

thats one heck of a length flex to use in a main hydraulic line  you can loose a lot of  volume as it expands under pressure 

why  a flexi ???

Pete

[dougbgt6]

I got one for my clutch master cylinder to slave off ebay, the slave is on the bell housing and the engine swings about in relation to the master cylinder so I flexible pipe is a good idea. 

The normal place for a servo is on the bulkhead so there is no movement between it and the master cylinder and I would prefer a solid connection.

Doug

[Gully]

8 minutes ago, dougbgt6 said:

I wouldn't be happy with a flexible hose in the brake line.

 

Would it make that much difference? There are already 4 flexy hoses connecting the brake lines to the calipers and slave cylinders?

Gully

[johny]

Motorbikes use long lengths of hose especially on the front brakes without problems. However its probably different (smaller bore) hose and I dont know how the fluid pressures generated compare...

[Anglefire]

33 minutes ago, Pete Lewis said:

thats one heck of a length flex to use in a main hydraulic line  you can loose a lot of  volume as it expands under pressure 

why  a flexi ???

Pete

I would guess the braid is noted to limit the expansion possibilities - though I would have thought a short flexy at both ends and a solid in the middle better - depending on how its all sitting!

[Pete Lewis]

brake line pressure is vastly higher than clutch systems so on a clutch fine 

adding 72cm 29" of flex on top of the already existing sounds a good plan for a squidgy pedal 

all flexibles balloon a little  under pressure and to dream of making your own up with fittings sounds a plan for the ditch 

and insurance implications can  creep in here .

Pete

 

[Mathew]

1 hour ago, Colin Lindsay said:

You can buy it by the metre from Kit Car Suppliers but you'll have to add the ends yourself - something I never tried.

I'd reckon hydraulic hose manufacturers could make one up for you, although you may have to supply the ends for them to crimp on.

Did this on my spitfire as i needed imperial to banjo for the hilux brakes. Easy to fit, just like plumbing compression fittings.

[Pete Lewis]

we often all fit braided flex hoses     have you seen the puny tube thats inside the Braiding 

really fills you with confidence     makes you wonder whats wrong with twin walled reinforced rubber 

unless its  not got some eastern rubber 

but the sun is coming   hooray 

[Pete Lewis]

5 minutes ago, Mathew said:

just like plumbing compression

but some brake lines have 2000+ psi with a big size 10 on the pedal in a panic 

bit different to the bath tap 

[Mad4classics]

19 minutes ago, Pete Lewis said:

adding 72cm 29" of flex on top of the already existing sounds a good plan for a squidgy pedal 

I have to agree with Pete I'm afraid - Stick with solid as far as possible!

But there are places that will make up flexible brake lines properly for you to any specification.

I've used these people to make up front brake lines for the popular Ford Fiesta disk conversion on a Mini, which requires very non-standard fittings.

http://www.bgcmotorsport.co.uk/

David

[JohnD]

Anyone who has watched Project Binky will know that the Bad Obsession boys used braided brake hose throughout, and when warned about "ballooning under pressure", as Pete says, totally rubbished the idea.     I have it for the essentially flexy bits in the race car ( it's bloody expensive!) And it does NOT 'balloon', Pete!

Think about it.  The teflon liner is flexible, and the outer braid will expand on size, but only by shortening.   Which it can't do as it is held at each end by the connectors.

There is a PB episode where they demonstrate how to fit the connections, but I can't find it for you at present.

John

[Mathew]

16 minutes ago, Pete Lewis said:

but some brake lines have 2000+ psi with a big size 10 on the pedal in a panic 

bit different to the bath tap 

How do you join the brake pipes to the flexi's . Is it not a mechanical seal? 

[JohnD]

At the same connector as a rubber flexible hose would.

[hardhatharry]

I have used braided on quite a few track and race bikes without an issue. Deffo doesn't balloon under pressure as they wouldn't use them extensively on race cars. Its expensive but doesn't limit the performance.

The ends are 3/8 unf aren't they?

[dougbgt6]

3 hours ago, Gully said:

Would it make that much difference? There are already 4 flexy hoses connecting the brake lines to the calipers and slave cylinders?

Very true Gully, that's why I edited it, but you saw it before I could finish! What I meant was what Pete said about pressure.

Doug

[Mathew]

If the servo is on the bulkhead i would use solid pipework, as its neater and only two joints. If however it has to be mounted elsewhere i would have no problem with a flexible hose. I have made lines up for large machines more than 2 metres long in rubber using a mechanical crimp tool running 10000 psi plus. Thats why i put "like" plumbing. It is surprisingly easy if your competent. Like in all the manuals if unsure about braking components seek professional advice and there are plenty of companies that can make up lines for you. (I do have a qualification in making these lines up, from a company that make lines.)

[JohnD]

A useul place to ask is anywhere supplying hydraulics to industry.  My local 'shop' provided cramped on fittings and inch wide hoses for my oil cooler, much better than the pushed on goes from the usual suspects.