Gravity brake fluid flush

[xsr]

Hi,
Planning to change my brake fluid on my 2016 Mazda 3 (~80K miles). I might just do gravity as it is much simpler.

Is there any benefit between the gravity method and 2 person or just time savings?

The process seems to be opening the bleeder screws and keeping the reservoir topped up?

 

[Nessism1]

With modern ABS systems, using something like a pressurized cap over the master reservoir works well. No need for two people. The tool pays for itself with the first usage. Highly recommended. I use Motive.

 

[Lubener]

I never had much luck or patience for gravity bleeding...I would replace the bleeder screws with speed bleeders. It has a one way check valve built in to prevent air from being sucked in when the pedal is released. A one man job.

 

[4wd]

I never had much luck or patience for gravity bleeding...I would replace the bleeder screws with speed bleeders. It has a one way check valve built in to prevent air from being sucked in when the pedal is released. A one man job.

Any idea why the OEM does not use them ? - not even that expensive

 

[Mechanician]

Any idea why the OEM does not use them ? - not even that expensive

In 2025 GM produced 6.18 million vehicles.
If they had used those, the engineer that cut them from production would have received an "atta-boy!"
Edit: Or "atta-girl!"

 

[4wd]

In 2025 GM produced 6.18 million vehicles.
If they had used those, the engineer that cut them from production would have received an "atta-boy!"

No revelation there …
They have that decision on hundreds and hundreds of parts …

 

[Mechanician]

No revelation there …
They have that decision on hundreds and hundreds of parts …

Yes the balancing act is weighted heavily toward "need to have", over "nice to have."
Unless the Marketing department can convince someone sales would improve.

 

[4wd]

Yes the balancing act is weighted heavily toward "need to have", over "nice to have."
Unless the Marketing department can convince someone sales would improve.

Probably take pressure from dealerships - like one day - after owning many - I crawled under my new Silverado to find the skid pan was no longer blocking the drain bolt and oil filter !
(Two oil changes for free era)

 

[skyactiv]

You can do it yourself, no need for a helper. I posted This Thread in 2016. Get a Orville Redenbocker 30 ounce bottle and a 1/4" I.D. hose. It works well.

 

[Nessism1]

One issue that can and does occur is air leakage around the bleeder nipple threads. That's why pressure bleeding is good; it doesn't care. For gravity bleeding or using speed bleeders, it may be worth the effort to remove the bleeder and wrap them with teflon tape first. Of course, the system will be open to air when you do this, though.

 

[Sequoiasoon]

One issue that can and does occur is air leakage around the bleeder nipple threads. That's why pressure bleeding is good; it doesn't care. For gravity bleeding or using speed bleeders, it may be worth the effort to remove the bleeder and wrap them with teflon tape first. Of course, the system will be open to air when you do this, though.

I've seen discussion with those using the vacuum bleeders also. Many just apply a bead of grease around the bleeder when loosened to created that slight seal. They wipe off after and spray with brake cleaner.

Many now use the bi-directional scan tools and let the ABS pump do its thing so that unit gets new fluid also.

 

[D60]

Bottom line, if you have access to a second person, do that.

 

[NibbanaBanana]

ChrisFix posted this bottle method years ago.

I've been using it ever since. It almost always has worked great for me. One time I couldn't get it to bleed on the passenger front caliper of my 2002 E150. Had to use the Mighty Vac. Put some silicon brake grease around the top of the bleeder screw to seal the threads. Whatever it costs in tools is almost irrelevant these days compared to paying a shop $100+ per hour. Bleed/change fluid in your brakes every 30K miles and you will never have a problem.