I am putting a new Master Cylinder on and want to do a gravity bleed. I have search but have not found out what kind of flow I should expect to see out of the open brake bleeder. Should I see a steady flow, slow dripping flow or a fast dripping flow.

Thanks
8Valve

 

All four of mine were very slow and after trying over and over it did not work. Save your self some aggravation and get a Motive pressure bleeder.

 

Bench bleed your new master cylinder before you install it as that'll cut the bleeding time to about 10%. To bench bleed it you just fill both reservoirs almost full then with two of your fingers covering the outlet ports slowly push the piston in until it bottoms while keeping your two fingers pressed firmly against the ports. Your fingers will act like check valves as fluid can be blown out but air can't be sucked back in.

Once you get it bled install it, tighten the two lines, keep the lid off, then open the right rear bleeder valves (one at a time) and wait until fluid is dripping at a steady rate like one drop per second and let it continue dripping until the fluid coming out is clear. Close off that bleeder and open the other bleeder and repeat the process. Then bleed the left rear caliper the same way then bleed both of the front calipers (only one bleeder screw on the front calipers).

Once you get all four of the calipers bled top the fluid level off in the reservoir and replace the cap. Gravity bleeding always works but it does take about 30 minutes to bleed all four calipers.

 

I have done mine before and had no problem. i do not know why some people have trouble doing it. There will a steady flow, you will not see it in the hose but see the bottle fill up.
Hope you can get it done.
Larry

 

When I gravity bleed I put a little brake fluid in the container so it covers the hose end.I wait for the air bubbles to stop,then you know it's bleed.

 

Thanks Guys;
Very familiar with bench bleeding both brake Master Cyl's and Hydraulic Clutch Masters. I was curious on the flow rate at the bleeder.

I used to use a Mite Vac and suction bleed. But you always get some air bubbles from the air going past the bleeder threads. One of these days I am going to spend a few bucks and make my own copy of the plastic pump up tank type.

8Valve

 

Why would that cause a problem? When you close the bleeder, vacuum draws the remaining air out along with the last bit of fluid. I've used the Mity-Vac on all our vehicles, and it always produces a solid pedal. Just sayin'...

 

Just read all the threads and FWIW I only use the gravity bleed procedure now..I have an almost brand new Motive Bleed Kit..It was used only once for a systems pressure check and I decided that the GB system worked better for me....I have the Motive kit for sale and if you decide to go that direction I'll give you a good deal...
mk's78
Mike

 

I gravity bleed each time I need to drain the fluid from my cars. One other thing I do while the fluid is draining is I get a rubber mallet and give the calipers a few light hits while its draining. Might be my imagination but it seems to knock some bubbles loose.

 

I just GB my fronts this past Friday. The flow rate is dependent on how much you open the bleeder screw. My flow rate was a fast drip. I would estimate about two full turns or less on the bleed screws. I bled about a pint thru each side. Worked great.