damaged brake line

bucknbuzz · 28-09-2019, 11:58 AM

Picked up a twig on the dirt road near home, it wedged in between the 2 rear brake lines that run down the drivers side of the exhaust. Result is I now have a leaking brake line which drains the reservoir. Can this be cut and a plastic tube be clamped over the pipe, or is there other options to replacing the whole line?

**aussiblue** · 28-09-2019, 12:30 PM

Plastic and/or nylon tubing cannot be used; it cannot hold the high hydraulic pressure of modern braking systems and is not heat resistant (as an aside in the 70's you could actually buy special hard black nylon brake line tubing for non-power assisted brake systems but it vanished from the market as braking systems improved). The other issue is that every time you hit the brake pedal the hose will try to both straighten out and expand rather than transfer fluid and pressure and this will cause a very soft brake pedal. Note you will be legally and morally culpable if you (or a subsequent owners of the vehicle) has a brake failure and someone is injured or killed due to the use of non-OEM brake lines or after-market identical specification lines. Replacing the whole line with an OEM line is the optimal and preferred solution. Yes; you can buy metal bundy brake line tubing and suitable joiners (or the correct diameter and metal type if you know these specs) from Repco and brake specialist but I would be getting a complete new OEM line even if from a wreckers.

Nylon brake lines are still used in some racing application (especially speedway bikes where weight is a factor and lines are short with gentle curves) but are not suitable or legal in street use e.g. https://www.speedwaymotors.com/Speed...-Kit,1993.html and https://www.ianboettcherraceparts.co...-ALL48018.html Even with these you have to very careful how they are routed because of there tendency to straighten rather than transfer pressure when the brakes are applied.

**aussiblue** · 28-09-2019, 01:04 PM

Clamping a pieces of tubing over the broken pipe will also likely create a slow leak as it will be near impossible to get a leak free seal with hose clamps.

**aussiblue** · 28-09-2019, 02:12 PM

A good brake shop could cut the line at the leak point fit a hard line compression joiner and a make a new hard line back to the rear T junction or to any other nearest existing joint/junction or brake piston. However, due to liability concerns, most would likely prefer to fit a new OEM line. There are also likely to be RWC failure issues with any patch job like the one you suggested. At best it's a high risk temporary measure so you can drive slowly and very cautiously to a brake shop.

**aussiblue** · 28-09-2019, 02:25 PM

This is the best way to do a temporary repair: https://www.youtube.com/watch?v=AzSYIwNKcLM and https://www.youtube.com/watch?v=m94L6f7gejY

GTLEGEND · 28-09-2019, 09:21 PM

What model Focus do you have? I would not attempt to repair the line (unless temporary to get you home). You are talking brakes here, best to replace the whole section of that line(s). If you can take a pic, we can help find what part you need.

bucknbuzz · 01-10-2019, 09:34 AM

Quote:

Originally Posted by GTLEGEND

What model Focus do you have? I would not attempt to repair the line (unless temporary to get you home). You are talking brakes here, best to replace the whole section of that line(s). If you can take a pic, we can help find what part you need.

its a 2010 LV tdci, but having read all the comments, i fully agree that an entire new line is called for.

thanks everyone, much appreciated.