Hoping to get some general help on my 2007 Buick Lucerne brake system. My daughter was driving and lost the brakes. Turns out it was a rusted brake line, and pretty much all the fluid drained out. I decided to replace all the brake lines as they were all pretty rusty. That brings me to my few questions.

I bought lines off the shelf from Oreilly Auto Parts. I bought 3/16" line and it seems to fit well where it adapts to the rubber hose end, as well as at the abs module but I am concerned maybe the thread size isn't right. The old ones had a larger nut on them, than the new ones, but they thread in nicely by hand, and a side by side comparison of the threads seems to match up. From what I can find, the threads are supposed to be M10x1. I am also wondering if I got the right flare on the lines. I should be able to compare that with the old ones I assume?

I have one connection at the abs module that won't stop leaking even with no pressure on the system. I'm not sure what I can do about that.

I would like to replace the front right brake line, but I see on the wheel end it has one size fitting, and on the abs module it is another size. Is there an adapter that would work to convert this, and what size would the abs module be?

I took the master cylinder off to bench bleed it. I have a bench bleed kit with the plastic adapters, but none seem to fit right. Does anyone know what size the threads are on the master cylinder so I can use the right size plastic adapter? I THINK it is 13x1.5. I'm also wondering if there are supposed to be washers between the two connections and the master cylinder, as well as if there's supposed to be a gasket or o-ring between the booster and the master cylinder. I will attach a couple of pictures.

Since the car lost most if not all of the fluid, what is the process for bleeding the ABS brakes? I've read that a scan tool may be required, but is there an alternative method to doing that? If not, any recommendations on a scan tool that will help me with this process? I'm familiar with bleeding brakes, just not after all the fluid has drained from an abs system.

Are there supposed to be any washers between the brake line fitting on the end where it attaches to the abs module?

Does anyone ever use any thread sealant? As I understand it, it is typically not recommended.

Thank you in advance for any help, it is much appreciated.

 

First , ALL your brake line fittings are METRIC and are usually colored blue. You need to be careful as some brake tubing utilizes a bubble flare and requires a special flaring tool to make them
As a rule we never put any unions in a brake line.
The ABS modulator has certain solenoid valves that open to dump brake pressure and those valves should be operated to allow any trapped air in the line to pass through and exit.when bleeding the system.
Some claim you can bleed the system without a capable scan tool, but I have never tried that..
It would be better if you obtained the correct fittings without using any adapters.
Something of which you may not be aware, when she lost the brake pedal it very likely went to the floor.When that happens, the abrasive sediment in the master cyl bore scores the rubber cups and the master will no longer hold brake pressure and will sink to the floor and now must be replaced. Expect that..
I would suggest you get hold of a good brake system manual and read through the things you should know, , they are much different from older brake systems.

 

Great information. Much appreciated. It’s clear that I bought the wrong size brake line. Should have double checked rather than rely on the parts store experts. My fault. Can you help me get going in the right direction? Looks like they have the right flare, just the wrong size nut.

What tubing line should I get and where can I get it? Same question with fittings and a flaring tool. The picture I’ve attached shows the old flare. I want to do this the right way, brakes are far too important to mess around with.

The flare in the picture from the caliper hose side looks like a double flare. Is it possible that the side on the abs valve modulator would be a bubble flare?

I bought a scan tool that will allow me to do the proper brake bleeding, but do I need to bleed them like a normal car without abs first, then bleed with the scan tool, or just go right to the scan tool?

The pedal did go to the floor. Is it your recommendation that I replace the master cylinder as well? I have no problem with doing that.

The rear fittings all appear to be m10x1.00, however the front fittings seem to be larger, even though they use the same size tube. Where would I be able to find out exactly what fitting size I need for those? My best estimate is that they are m12x1.00.

Any suggestions for a good brake manual?



Thanks again for your help.