Fixing rusty brake lines

[buck91]

Well, the job for this weekend will be replacing a rusted and leaking rear brake hard line on my Mustang. For the most part, it shouldn't be a terrible job but I'm a little confused. The line is fairly rusty at the rear but after passing over the axle becomes coated in a black plastic. Is there a way to splice into the line when its plastic coated?

I figure I'll grab a roll of NiCop tubing and do as much as I can, but with the way its routed through my SFC's and a factory x-brace going much more foward than mid-car where its plastic coated will be very tough.

 

[Donald]

You can splice with a double flare flaring tool.

I would replace the entire line were it my vehicle.

 

[OneEyeJack]

Don't take chances. Replace the lines. Brakes are too important to mess with shortcuts.

 

[ShotGun429]

replace the entire line. This is what salt does to the lines

 

[djb]

Remember, if brake line is 1% rusted, it's 90+% of the way through its life.

Visible rust means that the coating or plating is thin or gone. Even if you cut back to "good" tubing, you are further thinning or cracking the aged surface when you flare. Rust will pick up at that point. Unless it's really difficult to replace the line (e.g. through a factory-welded part of the body) it is best to replace the whole line.

After it's off, cut it open to check for corrosion on the inside. The inside surface should be factory fresh. If it's not, flush more frequently and plan on more replacement work.

 

[larryinnewyork]

When I bought my Ford Ranger in 2002, I coated all the 'metal' Brake Lines with Never-Seize.

Today, 14 years later, they still look brand new.
I know this because I recently cleaned a small area of brake line in front and along rear axle
using a high pressure car wash hose.

So after replacing your brake lines, get out your can of Never-Seize.

 

[buck91]

Picked up a roll of NiCopp and some fresh fittings. Guy also sold me some compression fittings to serve as splices if I can't make it all in a single run- those look like they will have to be returned for proper flare fittings...

 

[Lubener]

Originally Posted By: buck91
Picked up a roll of NiCopp and some fresh fittings. Guy also sold me some compression fittings to serve as splices if I can't make it all in a single run- those look like they will have to be returned for proper flare fittings...


You do not want to use compression fittings in your brake system. They make "unions" to splice the lines together but in some states, your car won't pass inspections if they see a union of any kind.

 

[buck91]

This is a fun line... stopping for a little break ATM, but without dropping the exhaust, x-brace and SFC's I had to cut the original line out in pieces. Going to try running the new line a slightly different route.

Anyways, found what appears to be an OEM union in the line. Looks to use a bubble flare on one end mated directly to a double flare. Very easy with the right fittings.

 

[SHOZ]

I found the brake lines very reasonable from Ford for my Taurus. Two front to back lines for $100 and got them the next day.

 

[dlundblad]

Not to do a thread hijack, but with the folks recommending an entire line replacement, it makes me wont how this is cleanly and correctly done.

If it's disconnected at the master cylinder, what would keep air from getting in? (Air = bad right? You never want to run the reservoir dry when doing a brake fluid flush for example.)

Combine that with fluid leaking everywhere along with fishing the new line in place and time is really of the essence.

 

[SHOZ]

Not at the MC but either the ABS pump or there may be a distribution block located in the engine compartment. In the rear they maybe another block that cuts pressure when braking to the rear.

 

[George7941]

Air getting into the master cylinder is not as big of a problem as you think it is. You could have the entire system - m/c and all the lines full of air and it can all be bled out.

You can take your time fishing in the new line and hook up the new line to the m/c or wherever after you are done installing the line.

 

[Snoman002]

I have replaced a section once and it was very difficult to get a good flare on the old tubing. When a few months later the rear line on my s-10 went bad I made a whole new one, to include hand bending the curl near the MC.

Compression fittings on brake lines are illegal and if the guy who sold them to you knew you were doing a car with them he can loose his job and the company can be fined. In a disk brake system the pressures that can be reached are 2-3 times higher than the rating of a compression fitting. Sadly that just means the brakes will feel fine and then fail in an emergency.

 

[buck91]

Yeah, decided against the compression fittings after reading some more. Just sucked it up and fished the line through- pretty rough run on a 96 GT! Thankfully, NiCopp is very forgiving and even flares easily in awkward positions.

 

[corndogzombie]

Just go on rock auto or to your local parts place and Oder the replacement for the whole line. It will be done then and no surprise loss of breaks going 60 around a bend

 

[NibbanaBanana]

My experience is that never seize is an excellent anti-seize lubricant but not all that great as a corrosion inhibiting coating. I coated a cat with it at every oil change. (Yep, it smoked for a few miles.) I didn't coat the cat on an identical car. Cats rusted out in exactly the same miles.

If it's a low temperature application like brake lines, white lithium grease is an excellent rust preventative. It doesn't wash off. I always coat new brake lines in the stuff and they never rust and last for the life of the vehicle.

I'm convinced that all the other problems with brakes will be prevented with regular fluid changes.

 

[George7941]

Originally Posted By: NibbanaBanana
If it's a low temperature application like brake lines, white lithium grease is an excellent rust preventative. It doesn't wash off. I always coat new brake lines in the stuff and they never rust and last for the life of the vehicle.

I have to disagree with you. Having lived in the rust belt for decades and having tried various substances to stave off rust and corrosion, my experience is that any grease is only effective for about a year and then, because it gets contaminated with salt and moisture, any grease like coating only promotes corrosion. The only effective long term fix is constant reapplication (yearly) of a light oil like Krown, Fluid Film, Corrosion X, Corrosion Block etc.

There are occasional posts about someone having coated their brake lines with antiseize or grease once and the brake lines never develop rust afterwards. It just has not been my experience.

Very similar to rustproofing cars. Thick one time coatings do not work, yearly applications of a light creeping oil is what works.