I have to replace a section of my brake line. I was wondering, do I bleed all brakes after I get the line replaced? The old line goes to the back driver’s side brake. Do I just bleed that one or all? Thanks.
I would go for a complete brake fluid change, all plus!
Are you replacing a hard steel line or a rubber flex hose?? Either way, that brake must be bled. It’s probably wise to bleed the entire system…
If the brake line leaked enough fluid to drain the master cylinder empty, you have to bleed everything. And don’t forget, if you pop a line in one place, there’s probably a few other weak spots under there too. Consider changing all the lines if you’re keeping the car. If you want to do it right (like manufacturers SHOULD do), you can probably order pre-bent STAINLESS STEEL lines. There are a few on-line companies that have these for a wide selection of vehicles.
Lastly, be sure you’re double flaring the connections. Single flares are a no-no and I wouldn’t trust compression fittings.
If you can somehow manage to replace the line section without ever fully draining the master cylinder, you probably only need to bleed the single brake. Fortunately, this isn’t something you need to guess about. If, after replacing the line section and bleeding the brake you’ve been working on, you need to pump the brake to get full pedal, then you need to get any trapped air out of the master cylinder and possibly bleed the other three brakes. Probably the only way to get into trouble is to drive off without testing the brake pedal.