replacing all brake lines: need advice

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Car is 2000 Mazda MPV. There are rust on hard lines undercarriage, and at wheels. The rust does not inspire confidence, though there has been no leaks (knock on wood). I am seriously thinking about replacing all the hard lines as well as the flex hoses (don't want to fight the connection). I have never done this before, and nervous about the ins and outs of doing this job. Please could I have your advice?

1. I can find all pre-bent lines (except for left rear) at dealership (and online sources), the left rear long line is NLA (no longer available). Using pre-bent lines is currently not my option for reasons a) they are steel lines with a coating, and I live in Albany, NY; b) it does not appear to be possible to put the pre-bent lines in without tearing the car to the bones, and this is the primary reason.

2. I read good things about the copper-nickel lines, and currently thinking about going this way, and do flares and bends by myself. NAPA sells a single size flare tool that seems to be a good one, and I think I can practice and get good flares. Also will get the OEM flex hoses.

3. My biggest concern is how to get the new line in place. I am thinking about using the old line as template for one end to get it started, and leave the other end straight so that I can thread it and bend it inline as I reroute the lines... but again, this is just thinking.....

Please let me know if I am on the wrong path. Thanks.
 
To answer your questions:
1. yes you can get pre bent if available but I wouldn't. They are expensive and will be difficult wiggling into place. I always bent them myself with straight lines which I previously measured.

2.I would go with the copper nickle lines too and you shouldn't have to do it again. They bend easily for installation. Just make sure you are using the correct flare for your car and mating connections.

3. I have done entire lengths in 2-3 sections (pre-flared sticks)and coupled together with the proper unions. If you buy a coil, you will have to get fittings which added up can get pricey.I was able to bend these lines both by hand and using a tubing bender working along. It is not a very difficult job when you are replacing everything. Spray the connections with PB Blaster and let work overnight. Remove the old and put the new in the existing hangars.
 
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The original lines have lasted 17 yrs already. Just saying. Replacing with copper lines should be easier than working with steel lines. I've never have used copper, but I never had any trouble with steel line replacement either. I know the hose /steel line can be a a pain. Then, I started cutting the lines flush with the hoses That way I could use a 6 point socket on the BL fitting. Lines are typically clipped to the underside at regular intervals. Use these to secure the line as you form it by hand. Will the lines be as uniform as factory? Probably not. As long as the line functions and is secured in place that is good enough. One snag is that, you dont want to let air into the MC or the ABS pump. I suggest starting out with plugs and line caps of some sort. I solved the problem by constantly topping off the MC.I wasted a qt of BF this way. a few plugs and caps would save money and mess. In addition to the flaring tool, get a mini tubing cutter and a file to remove the sharp edges of the cut. Best of luck. Please post your progress. TIA.
 
I would inspect the lines all the way to the front. Chances are that the lines going from the MC and at least past the fire wall are good and this is usually the portion that is the hardest to do. Going all new sounds good on paper, but why make more work for yourself, especially on such an old vehicle, than you have to?
If the lines up front look good, there should be no problems with splicing them.

IMO, I would only do the whole thing if the front also shows signs of corrosion.
 
Just so you know Parker stores sell a flexible coated steel braided line that's pretty amazing to work with
 
I replaced all the fuel, fuel vent and brake lines on my old E34. I bought BMW fuel and fuel vent lines, those were not pre-bent and required cutting and splicing to install without dropping the rear subframe. One of the other issues is that unless you have the car on a lift it is difficult to swing around long lines with limited clearance.

After that silliness I bought cupro-nickel brake pipe from a place online. I bought only enough for the long lines that ran to the back, the shorter front lines I got from BMW as they did not run anywhere that wasn't accessible. The cupro-nickel lines are amazing to work with and can be bent and unbent very easily to get into position. It is also easy to flare, but make sure you're getting the correct tool for your Mazda. My BMW for example is not a "flare" as such but is an ISO bubble flare.

The worst problem on my BMW was getting all the clamps undone. They are held together with a single screw going into a stud welded to the body, and after 20+ years some were rusted pretty good. Amazingly though most came apart with some help (I Dremeled a slot in the Philips head screw) but some were beyond that and twisted off the head. In typical BMW fashion though there were more clamps than were needed so I only had to improvise attaching a couple.

The worst looking lines on my BMW were the fuel vent lines, but when I had them off there was still a lot of meat left to the metal. They looked a lot worse than they actually were. But as a comparison, the brake and fuel lines on my almost as old Japanese cars have no rust whatsoever.
 
Thanks for all your kind responses. The Mazdas use American standard flare, which is a double flare or inverted flare, but with metric thread on the fitting, M10x1.0. I checked the car, all the lines from ABS out are the same size.

The lines going to rear drums are from a fitting that was mounted on the firewall, they are good till the bend going to bottom of the car, but it's about 6 inches of line before the rust starts, so I'd think not to do splicing.

Good advice on not getting air in the ABS unit. I'll look for suitable plugs and get more brake fluid. My thinking is to do one line at a time, 1st remove line from ABS for front wheels, and firewall fitting for rear wheels, then plug the hole ASAP. Then remove the whole line to front flex hose and rear drum cylinder (thanks for the advice on cutting it flush and using a 6-point socket). Then work/connect in the new line from wheel back to the ABS unit and reconnect there. This may not work for all 4 wheels, esp front, I'll then need to start new line from ABS, and plug the other end. I'll need to have a good estimate for the length of each line, planning on using a string to follow the old line once I get it out.
 
Originally Posted By: NStuart
Just so you know Parker stores sell a flexible coated steel braided line that's pretty amazing to work with


Hi, Stuart, you are talking about the flex hoses, right?
 
Originally Posted By: windeye
Originally Posted By: NStuart
Just so you know Parker stores sell a flexible coated steel braided line that's pretty amazing to work with


Hi, Stuart, you are talking about the flex hoses, right?


My boat trailer brake upgrade kit included a long 20' flex line.
 
Originally Posted By: windeye
Good advice on not getting air in the ABS unit. I'll look for suitable plugs and get more brake fluid. My thinking is to do one line at a time, 1st remove line from ABS for front wheels, and firewall fitting for rear wheels, then plug the hole ASAP. Then remove the whole line to front flex hose and rear drum cylinder (thanks for the advice on cutting it flush and using a 6-point socket). Then work/connect in the new line from wheel back to the ABS unit and reconnect there. This may not work for all 4 wheels, esp front, I'll then need to start new line from ABS, and plug the other end. I'll need to have a good estimate for the length of each line, planning on using a string to follow the old line once I get it out.

On my BMW you can block/hold the brake pedal about halfway down and that will keep the master cylinder and reservoir from draining. But on that car you can manually energize the ABS solenoids and allow it to be bled properly. It would have been too much work to try and keep the thing from bleeding out completely, more work than just hot wiring the solenoids.
 
I've done a number of complete brake re-line jobs on rusty vehicles. A good double flare kit and tubing cutter will make yourself an expert. Most auto supply houses carry a good set of stock lines that you can bend, trim, and couple to match the lines you remove. You can buy a tubing bender; but for the tighter bends I use a steel bar mounted in a vise to bend tubes without kinking.
 
Originally Posted By: Lubener
To answer your questions:
1. yes you can get pre bent if available but I wouldn't. They are expensive and will be difficult wiggling into place.


Maybe for a Mazda, but for the 2000 Dodge truck I used pre-bent ones from the dealer and they were cheap and easy to install. Dealer had them the next day too.
 
Originally Posted By: zzyzzx
Originally Posted By: Lubener
To answer your questions:
1. yes you can get pre bent if available but I wouldn't. They are expensive and will be difficult wiggling into place.


Maybe for a Mazda, but for the 2000 Dodge truck I used pre-bent ones from the dealer and they were cheap and easy to install. Dealer had them the next day too.


The brake lines, along with the fuel lines (larger diameter), run along the driver side of the car, and above the fuel tank. no wiggle room there. Plus I have to make one line by myself, might as well do them all, and the copper-nickel's resisting road salt is good, and easy to flare and bend. I do need to get a good bending tool, have a cutter already. Thanks.
 
Originally Posted By: Chris142
Bare with me because we dont get rusty stuff here. Can you paint the lines to protect them?


The OEM lines actually have tight vinyl (?) sleeves on them. At the connection to the flex hose, the sleeve was cut back (1/2in or so), and there you have rust. Under the car, maybe the vinyl became brittle over time and flake off, so rust began. As was pointed out by Andyd, it has been 17 years, a bit too late to paint them ;-)
 
Originally Posted By: Kestas
I've done a number of complete brake re-line jobs on rusty vehicles. A good double flare kit and tubing cutter will make yourself an expert. Most auto supply houses carry a good set of stock lines that you can bend, trim, and couple to match the lines you remove. You can buy a tubing bender; but for the tighter bends I use a steel bar mounted in a vise to bend tubes without kinking.


The closest NAPA store has 25-ft coil copper-nickel. they also have a good, single size flare tool. What kind of bending tool you recommend? the plier kind?
 
Originally Posted By: kschachn
I replaced all the fuel, fuel vent and brake lines on my old E34. I bought BMW fuel and fuel vent lines, those were not pre-bent and required cutting and splicing to install without dropping the rear subframe. One of the other issues is that unless you have the car on a lift it is difficult to swing around long lines with limited clearance.

After that silliness I bought cupro-nickel brake pipe from a place online. I bought only enough for the long lines that ran to the back, the shorter front lines I got from BMW as they did not run anywhere that wasn't accessible. The cupro-nickel lines are amazing to work with and can be bent and unbent very easily to get into position. It is also easy to flare, but make sure you're getting the correct tool for your Mazda. My BMW for example is not a "flare" as such but is an ISO bubble flare.

The worst problem on my BMW was getting all the clamps undone. They are held together with a single screw going into a stud welded to the body, and after 20+ years some were rusted pretty good. Amazingly though most came apart with some help (I Dremeled a slot in the Philips head screw) but some were beyond that and twisted off the head. In typical BMW fashion though there were more clamps than were needed so I only had to improvise attaching a couple.

The worst looking lines on my BMW were the fuel vent lines, but when I had them off there was still a lot of meat left to the metal. They looked a lot worse than they actually were. But as a comparison, the brake and fuel lines on my almost as old Japanese cars have no rust whatsoever.


Thanks for the note. Most of the clips are plastic sticking into the body. Given the age, I would try to lube and carefully wiggle the brake line out. Maybe cut the line and move it in the longitudinal direction. If they break, i don't know what to do yet, need to study that. But I know I have to have the clips to hold the line to pass inspection.
 
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