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I have searched, and gravity bleeding is mentioned a lot, but coud someone list in very simple form the steps.
also:
how long should it take?
how do you know when your finished ?
thanks, in advance for your input !!
It is done the same way pressure bleeding is done without pumping the pedal or having a pressure bleeder.
I personally take the master cylinder cap off make sure it is full, then just open the bleeder starting farthest wheel to closest (RR-LR-RF-LF) and let it run till I get clean fluid and no signs of air bubbles, then close that one and move to the next. I usually fill the MC to the top and let it drain till the level is at the bottom of the slot in the chamber divider before refilling and moving on to the next one.
I have gravity bled more than pumping the pedal or pressure bleeding, it is my personal preference. But sometimes it can take quite a while, when I put LT1 brakes on the back of my 89 I used 3 qt bottles of fluid and several hours. But then I replaced the all hoses and lines from the prop to the rear calipers. I didn't need that much fluid or time but did it to feel more comfortable that I got all the junk out of the lines from making them, just piece of mind for me.
Personal opinion never rush anything related to my brakes, spending my time in the garage is cheaper than spending $$$at a body shop
I agree with bilms01, but if you have someone help you this procedure works beter than pumping forever. Start with loosening the bleed port and have somebody push the brake pedal down slow ask your friend to let you know when the pedal is down then close the port,tell him/her to go up and repeat the proceedure. This way you dont aeriate the fluid works well and seems to work faster than pumping, good for slave cylinders too
[quote=bilms01;3469874
I personally take the master cylinder cap off make sure it is full, then just open the bleeder starting farthest wheel to closest (RR-LR-RF-LF) and let it run till I get clean fluid and no signs of air bubbles, then close that one and move to the next. I usually fill the MC to the top and let it drain till the level is at the bottom of the slot in the chamber divider before refilling and moving on to the next one.
[/quote]
A few questions since I never done this before...Gravity Bleeding...
1. In order to gravity bleed, does the car have to be level or can you raise up one section at a time (as per brake) in order to have better access?
2. After filling the MC with clean fluid for each brake do you snap the MC lid back on or leave the MC open until all 4 brakes have been bled?
3. Do you need a hose attached to the bleeder or can you just let the fluid flow out to a catch bin?
4. Does this work on both disc and drum brakes?
Last edited by citydragon; 09-20-2007 at 11:15 AM.
Gravity bleeding by the real definition of gravity isn't completely accurate. It actually uses atmospheric pressure on the fluid level in the master cylinder to push the fluid out. Kind of like a bottle of water on a counter, leave the cap on tight and poke a hole in the bottom and see if the water drains, then take off the cap and see what happens. As far as the car being level, take the same bottle of water put a hose in the hole you made and raise the open end of the hose higher than the water level, it stops. Unless you jack up a wheel higher than the level of the master cylinder it will work.
Drain it anyway you want just depends of what you are willing to clean up when you are done.
It will work effectively on any hydraulic system with an unpressurized reservior. Think back to 5th grade physical science and you will understand how it works.
Gravity bleeding by the real definition of gravity isn't completely accurate. It actually uses atmospheric pressure on the fluid level in the master cylinder to push the fluid out. Kind of like a bottle of water on a counter, leave the cap on tight and poke a hole in the bottom and see if the water drains, then take off the cap and see what happens. As far as the car being level, take the same bottle of water put a hose in the hole you made and raise the open end of the hose higher than the water level, it stops. Unless you jack up a wheel higher than the level of the master cylinder it will work.
Drain it anyway you want just depends of what you are willing to clean up when you are done.
It will work effectively on any hydraulic system with an unpressurized reservior. Think back to 5th grade physical science and you will understand how it works.
Thanks! great!...I get it now...someone mentioned on another board that before you gravity bleed you should get the brakes/fluid hot by driving/stopping...any truth to that? Or just bleed cold?
