When do you have to bleed the brakes? (and other brake questions)

[BlahBlahYouToo]

I've done pads and rotors before but did not do anything with the fluids other than topping off the reservoir after I was done.

I just watched a video on youtube of a bleed and it seems pretty straightforward.

Also, is a bleed different from a full flush?

 

[BlahBlahYouToo]

bump

 

[fbrdphreak]

If the car is driven hard or a lot of miles, I would change the fluid every year. If not, every 2 should be fine. Or just go by the service internal in your manual.

I suppose you can go about servicing brake fluid two different ways. If you just need to get air out of the lines, you would "bleed" them to push the air bubbles out. You watch for the bubbles in the tubing hooked up to the bleed screw on the caliper. When you see no more bubbles, you're done.

But ideally you want to make sure you push enough fluid through each corner that there is no old fluid left in the line. This effectively flushes it.

It can be tricky to tell when the old fluid is out and the new fluid has made it to the caliper. You can find ATE racing brake fluid in blue and gold colors for this explicit reason.

 

[Viperoni]

Because bleeding the brakes pumps out fluid from either end of the system, doing it enoguh will result in a flushed system.

As stated, bleeding is only to get rid of air stuck in the lines, which should only happen when a hydraulic component of the system is leaking and/or has been replaced.

 

[BUTCH1]

No difference really. I do mine every 3 years or whenever pads/shoes need replacing..

 

[Gibson486]

You bleed the brakes to get rid of air in teh lines. It has to be done if you did any maintainance to the hydraulics of the brakes (calipers, brake hose, brake lines).

Flushing is the same process, but you bleed each line until you get the new liquid to come out of each line as opposed to just bleeding to get rid of air bubbles.

 

[Demon-Xanth]

When I would do it:
When there is a chance for air to get in the lines (ie: replaced caliper)
When you are replacing fluid, either due to age, overheating, or contamination.


Other than that, leave the sealed system sealed.

 

[BlahBlahYouToo]

So I guess when I did my rotors which required removal of the calipers, and I didn't flush the fluid, I introduced some air bubbles into the system.

 

[Demon-Xanth]

Usually you can remove the calipers from the HUB w/o disconnecting the lines.

 

[fbrdphreak]

So I guess when I did my rotors which required removal of the calipers, and I didn't flush the fluid, I introduced some air bubbles into the system.

Unlikely. More commonly this would happen if brakes were not bled properly, if you replace the brake hoses themselves (commonly done to replace rubber hoses with stainless steel ones), R&R the calipers or when bleeding let the master cylinder run dry.

 

[JulesMaximus]

There should be no reason for you to have to bleed your brakes unless you've removed brake lines from the calipers or replaced the master cylinder which would introduce air into the system.

Taking the calipers off the hub to do a brake job should not require bleeding, just leave the brake line attached to the caliper and hang the whole assembly up and out of the way.

The service interval for a complete brake system flush should be listed in your owner's manual. I think mine calls for this service every 30,000 miles (or every 2 years).

Bleeding the brakes just gets the air out of the system, flushing the brakes is basically replacing all the old brake fluid with fresh fluid.

 

[Gibson486]

So I guess when I did my rotors which required removal of the calipers, and I didn't flush the fluid, I introduced some air bubbles into the system.

If the calipers were not disconnected from the brake hose, you should be fine. No bleeding needed.

That said, you should flush your lines every 2 or 3 years.

 

[BlahBlahYouToo]

There should be no reason for you to have to bleed your brakes unless you've removed brake lines from the calipers or replaced the master cylinder which would introduce air into the system.

Taking the calipers off the hub to do a brake job should not require bleeding, just leave the brake line attached to the caliper and hang the whole assembly up and out of the way.

The service interval for a complete brake system flush should be listed in your owner's manual. I think mine calls for this service every 30,000 miles (or every 2 years).

Bleeding the brakes just gets the air out of the system, flushing the brakes is basically replacing all the old brake fluid with fresh fluid.

Yeah, that's what I did. Just hung the caliper on an arm with the line attached.
OK, I guess I'm well overdue for a full flush. But the brakes still stop the car hard.

The pad is wearing thin so I guess I'll replace pads and flush soon.