I was bleeding my brakes yesterday, attempting to replace some of the old fluid and do a flush.

I used the vacuum method at the nipple and couldn't seem to keep it from sucking air from around the nipple threads.

I opened the nipple only about a 1/4 turn, but I couldn't avoid having the vacuum I was applying pull air as well as a very small amount of brake fluid.

Any tips?

Thanks!

 

is it a pneumatic system or are you pumping? a quarter turn might be okay, but try opening it a little further. as long as you have the pump on the nipple and fluid in the pumps chamber, air shouldn't be sucked back into the caliper.

 

I'm using a small amount of negative (vacuum) pressure at the caliper end, to pull the fluid out.

No pumping of pedal of any sort. I leave the pedal alone completely.

 

lol, Yes I know... not that it matters but is it a pneumatic system or a manual pump?

 

I'm creating a small vacuum with a real vacuum...by taking the rubber tube from the nipple and putting it in a large jug that I'm creating the vacuum in.

 

I see

 

So you've never had a problem with either fluid coming out places other then the end of the nipple or when applying a vacuum, sucking air around the threads that show up as lots of little bubbles going down the tube?

 

It doesn't matter that you are sucking air from around the nipple (all that air is going into the vacuum). Open the bleeder as much as you have to, and a little push on the brake pedal can get the fluid moving, just make sure you have suction at the same time.

 

Thanks! I didn't know if my bleeders were faulty or what.

About how much fluid do i need to flush the entire system?

 

I would get at least two, probably 3 12oz bottles. Make sure you get as much of the old fluid out of the reservior, and replace it with new fluid before you start. The less dirty fluid left in the system, the less time it will take to flush it out.

 

I still think the best way is having 2 guys do this. Have one person pump the pedal and coordinate w/ the other guy at the caliper. I normally put a fishing air line on the bleeder and crack open it in the bottle. You dont' want a reverse siphon. Crack enough so that the pedal can pump and fluid doesn't drip but gets pushed through the air line tube.

Just make sure to keep reservoir full !

I've used this method for all my cars, on all makes and models and it's been great for me.

 

Make sure you have master cylinder cap off when bleeding, that may help a bit .
If I use vacuum pump I generally at end, final bleeding don't use it, just either natural gravity or with helper at brake ( I use it just to speed up fluid change ).
If you have long hose just let it go into container with some old brake fluid , then you don't even have to worry about the bleeder threads, just use brake pedal to get it flowing .

 

Just a thought I found in another forum.

Place either a 2x4 or a brick under your brake pedal. Makes it easier for person inside car to maintain even pressure while you open/close the bleeder. Of course, you'll remove the 2x4 / brick immediately afterwards, before you go driving off.

Also, use a piece of vacuum hose to drain old fluid into clear 2/3 liter soda pop bottle. Than way, you'll have less of a mess to worry about. Easily closed while taking it to the recycling center. Plus you'll be able to see the color of the draining fluid & know when to close the bleeder.