cargo247

How long does gravity bleed take? help!

I have all new lines calipers, I bench bled and installed now it’s been 6hrs gravity bleed so I gave the pedal some pumps and there are a few bubbles come up in the m/c is this normal
And still and just little brake flow in the inside r/r what’s wrong here.
I just closed everything up had enough what a pain in the azz
I am using dot 5 silicone
Will I have to pull the m/c off because of the bubbles?

Can someone give me the steps to do this please?

Sorry just a little frustrated right now!

thanks
Todd

wombvette

You have to get it going first to get the air out of the lines. It will not start on its own. Just use the old pump and release the fitting method until you get fluid to each caliper. Then the gravity process will not take long.

Oldguard 7

I bet you are it's a lot of trouble with these brake systems. A few members like Tom 454 swear by gravity bleeding. He has a write up on the different methods of bleeding brakes. If you have the vehicle up on jackstands, and have the bleeders open with catch containers, let mother nature do her thing, tap the rear calipers with a rubber mallet to free any bubbles that may be hung up toward the upper inner/outer bleeders. It also helps to have "speed" bleeders. These differ than the regular bleeders because they have a small check ball that does not allow air back into the bleeder like the regulars do. More replies will be forthcomng.

jimbo1972

I did a quick post on this the other day, you can do a search. I used a big syringe from the pharmacy to suck the fluid down to the caliper. took only about 5 minutes per wheel to do.
Good luck
Jimbo

bodaboom69

if you see bubbles coming out of the mc then you probably have to remove the mc again and bench bleed it. if air gets trapped in the mc it will never come out when installed on the car.
i've gravity bled quite a few vettes, sometimes it can take a while, i left my car for a few hours, and just checked the fluid level often.
the speed bleeders are a great idea, because you can pump the peddle with no assistance, because they have check ***** and won't let air re-enter the system.
i strongly agree with the rubber mallet, hit everything you can reach. the calipers, the mc, the lines and even the chassis. dislodge as many bubbles as you can. with the lines still open. then....the next day, do it again.

sly vette

I was in the process of gravity bleeding my brakes on my '69 when along comes a very well respected member of this forum. He was staying with me at the time. He promptly asked for some tubing and got the fluid to each caliper taking about 15 seconds each. He did get some in his mouth and promptly stated "That is what Labatt Blue is for"
What a beer snob...But he is a character!

Desert68

I have seen really tiny bubbles come up to the top in a bench bled, newly installed master cylinder and it worked fine.

hugie82

I disconnect the battery and depress the brake pedal an inch or two. Then fill the master to the top and open bleeders. Usaully with in a minute I have brake fluid at all four wheels. Do Not let the MC run dry Also if you only get fluid to the front or back, then the perportioning valve is stuck.

Shirley1978

9.8m/s^2

stingr69

It should take a long time if you have not ordered the Motive Products Pressure Bleeder in advance. Get one before you start and it only takes an hour or so. This should be in every C3 owners tool box as standard equipment.

-Mark.

redman76

I have felt your pain before. Replace m/c and brake lines. Thought I never get the fluid moving. Tried mini hand vac, gravity feed, etc. Nothing worked and I was getting very frustrated. Even had the wife pumping the brakes while I was loosening the bleeders. I still told her she was a big help though.

Ended up getting a buddy to pump the crap out of the brake pedal and presto . . . fluid gushing!!! Be sure to follow the bleeding sequence. Hang in, you'll get there

mooneyd

The silicone (DOT 5) is harder to bleed. Bubbles do not move as easily in it, sometimes not at all without some help.
Be patient "Grasshopper"

HamadUP

.. If I have to keep one tool only in my garage, I would choose a pressure bleeder.

bodaboom69

just remember, dot 3 brake fluid goes bad very fast when exposed to air. so if you have a pressure bleeder that does not have a rubber bladder to keep the fluid sealed from the ambiant air, the left over fluid will absord moisture and be junk in a month or so.

cargo247

Ok got it done ....AND THEN... just remember i have all new stuff on here and a LEAK not a small leak a nice one oh but were is it coming from? i thought the bleeder was not tight, not with my luck LEFT FRONT CALIPER OUTSIDE LOWER PISTON SEAL PISSING ALL OVER THE PLACE. now i must call corvette central to see what they will do about this oh but look at the time they are closed ......... i wounder if a sledge hammer would stop the leak


Has anyone had a return like this with corvette central and how did it go i have had them in a box for like 3 or 4 months till i was ready to put them on well i am ready its not.

Todd

cargo247

lol

LYLE

I had some luck with gravity bleading but if you have a sleeved master cyclinder some of them will not gravity blead if you wait a week. Their is a hole that is blocked by the sleeve that is needed only for gravity bleeding so the rebuilers skip doing it.