Brake system psi?

N

norwichmatt

New Member
Hi guys, started doing my master cylinder last weekend. Opened up can of worms, everything looking pretty poor... so the job has turned into a complete overhaul of the hydraulic systems.

Since everything else will be shiny new and I seriously rounded some flare nuts with the old vice grips I want to replace some of the pipe work.

Anyone know what sort of psi the X's brake system generates and if copper pipe is sufficient, or should I go for steel? Wanted to flare my own so to speak and copper would be easier to work with. I was looking at some copper pipe, rated safe at 1841psi, max load 2698 psi. Would this be suitable do you think?

Thanks in advance, this forum is an absolute gem for information... learned so much just reading the old posts but couldn't find this specific answer anywhere and it isn't in the service manual.
 
Most brake systems generate in the range of

1000 to 1300 psi.

I don't know about using copper tho. It's much softer than steel and although it won't burst until 1800 psi, it may expand some before that, draining off some of your braking energy. Also it "work hardens" in areas where it flexes slightly (chassis flex for example) and tends to become brittle and break in those areas. There's probably a good reason the manufacturers don't use copper for this application. Steel is no more difficult to work with given the proper tools. And if you are taking your life in your hands by reworking your brake system, you need the proper tools.

Pete
 
DO NOT USE COPPER!..

Copper tubing is totally unsuitable for brake lines because it fatigues at pressure. It is a recipe for disaster.

Ciao,
 
Never Use Copper Tubing In Automotive Applications !

Copper tubing for brake, fuel or etc is failure in process that will happen when least expected. Copper tubing work hardens under cyclic loading.

In brake system, think of the tubing expanding every time the brakes are applied, the contracts when the brakes are off. Each time this happens the copper tubing gets a bit harder and eventually, it will crack and fail.

There is a history to brake line tubing. One of the first reliable brake tubing mass manufactured was Bundy-Weld tubing. It became the standard offering in many cars. It's basically double wall annealed steel tubing that was brazed with copper. This was the first production tubing that was strong enough for brake line service.

http://www.fundinguniverse.com/company-histories/Bundy-Corporation-Company-History.html

Proper brake line is easily available from your local automotive suppler. Given a choice, use the plastic coated steel brake lines that are common in the majority of production cars today. It is not expensive or difficult to get the proper brake line tubing.

Alternatively, I use annealed, seamless, 302 stainless steel aircraft grade tubing for brake lines in project cars. At just over $5.00 per foot, it's not cheap, but works well and good flaring, cutting and bending tools are required if this tubing is used.

BTW, Facom makes a very nice flaring tool# 347.

Bernice
 
I used Cunifer ( copper, nickle, iron alloy) to redo my whole brake system. Volvo has been using it since the mid 70s. It is easy to work with. I got my material and rented the flaring tool from the company that Dan just mentioned www.fedhillusa.com. They were great people to deal with.
Their tool flares like a charm. Every single flare I made with it was perfect 1st time.
I actually made two complete sets of lines in 2 hours.

DSCN2080.jpg
 
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