I’m just finishing up replacing the rear drums and shoes on my 99 Honda Civic. The wheel cylinders were looking really beat up so I replaced them. I’ve read that while bleeding brakes it should be done in a specific sequence on all four wheels. However the Hayne’s guide I have for the car says that if the loss of pressure only occurred at one wheel you only need to bleed that one wheel. So which is it? Can I just bleed the rear brakes, or do I have to do all of them?
Thank you for the help.
The sequence (FYI) is to start at the furthest wheel from the master cylinder, and work your way through to the shortest path.
If the fluid drained from the master cylinder, you need to bleed that first. Then, you can work per axle, longest run, first. If you were careful enough with the lines so the master did not drain, then you don’t need to bleed it.
The fluid reservoir is separated so that both half’s (front and back) won’t both drain completely.
Now, for your question: Just do the rear.
Chase
The master cylinder reservoir is full. I made sure to plug the break line connector as soon as I disconnected the wheel cylinders. So just bleeding the rears should work for me?
Thanks again.
Yes.
The old sequence of furthest to closest doesn’t completely apply anymore. Todays systems have a cross brake system so you just do the rears first, then the fronts, which side doesn’t matter.
You can in this case only do the rears, but I would do all four, and bleed until you get fresh fluid at each wheel. This is a flush, some recommend this be done every 2 years, I generally do it anytime I work on the brakes. If you have ABS, be sure to follow any instructions for those. It usually requires unplugging the ABS module first.
When you flush, suck out the old fluid in the master cylinder reservoir first and then fill with fresh. Do not allow the reservoir to go dry while flushing/bleeding.
Wouldn’t sucking out the old fluid constitute letting the reservoir go dry.
You don’t want it to go dry while flushing/bleeding. If it goes dry before then, while you’re sucking the old fluid out, that’s fine. You keep it from going dry once you start the bleed process to keep air from getting into the lines from up top and making your bleeding job longer.
Bleeding all four brakes and doing a complete flush will probably take quite a bit of time, right. What would be the harm of not doing a flush? Because if I’m not risking anything immediate and major I think I’m going to opt to just do the rears. Because of work and going back to school I don’t have much time to work on this and I really need it back on the road.
Give yourself the normal amount of time to bleed the brakes, then add about an hour.
Clean out the master cylinder, then use new fluid, and bleed normally until you get new fluid at each wheel. Just be careful not to let the master run dry in the process, or you have to start again.
It’s already been 3 days, hasn’t it? Total time to do this flush really shouldn’t be more than an hour or two.
Chase
It took me 45 minutes to bleed my MR2’s brakes with an MC replacement. Just get someone to sit in the car and press the brake pedal when you tell them to.
The harm of not doing a flush depends on how old your brake fluid is. It ranges from 0 to hitting a semi because your brakes failed.
Thanks shadowfox, thats exactly what I would have responded with.