I have always done this when bleading the brakes. Use a turbey baster to get the old fluid out of the master cylinder, put in fresh, and bleed.

 

Today in the automotive advice column, there was a letter about DOT3. The columnist (who i am not a fan off for his usual response of take car to dealer), said to use the turkey baster trick several times over a couple of weeks. Tis would be the same thing as a beading type flush.

 

Thinking about this, I can see the pros and cons to both sides (big con is contaminating new fluid with old (which may have water in it).

 

So thoughts and opinions?

 

nipper

The brake fluid in the lines and calipers does NOT return to the reservoir.

 

To get fresh fluid to the entire system clean fluid needs to be bleed through the system.

 

Best method is to do as you say. Remove as much old fluid from the reservoir as possible and bleed new through. The more new you bleed through the less old that will be left to contaminate the new.

The brake fluid in the lines and calipers does NOT return to the reservoir.

 

To get fresh fluid to the entire system clean fluid needs to be bleed through the system.

 

Best method is to do as you say. Remove as much old fluid from the reservoir as possible and bleed new through. The more new you bleed through the less old that will be left to contaminate the new.

 

Thats what I thought, i was wondering if i missed something from someplace.

 

This guy Junior tend to piss me off at times, I read his column as a big ad for aldata and delaerships most the time.

 

nipper

If the density of H20 is greater than DOT 3?

 

Would any that came out of solution not stay at the lowest points in the system?

 

Thus backing up WA's method.

If the density of H20 is greater than DOT 3?

 

Would any that came out of solution not stay at the lowest points in the system?

 

Thus backing up WA's method.

 

The brake lines are skinny enough I don't think it'd really matter- even if there was something in the fluid that wanted to 'float', it'd be trapped.

 

Kinda like a weather inversion layer.

 

 

Dave

If the density of H20 is greater than DOT 3?

 

Would any that came out of solution not stay at the lowest points in the system?

 

Thus backing up WA's method.

 

Water won't come out of the fluid. Brake fluid is hydroscopic so it any water in the fluid gets distributed evenly.

 

I empty the reservoir with a syringe and vacuum bleed at the calipers. I even rigged up a nifty power bleeder with stuff from work:

 

 

Worked great on my friend's car.

well the water still reacts/pits the

bottom side of the wheel cylinders

in my Britsh cars anyhow.

so it must come out of solution somehow.

 

 

Make sure you coat the threads on the bleed nipples

with grease or antisieze in the

bleeder set up you use.

It prevents air from being drawn in.

But I'm sure you knew that.

 

Here's my EZ bleed, not as professional as yours

but ...

I think there has to be A LOT of water in the fluid for that to happen. The biggest problem is the reduced boiling point, though. The wet boiling point of a dot 4 fluid is 311F, which is a 30% reduction from the dry point. Really you should change the fluid every year or two.

 

Yeah we used that thing for the first time last weekend. It was ridiculous how quick and easy bleeding went compared to my mityvac. Also yes, I noticed how air gets sucked into the threads without a sealant of some sort.

 

That reminds me that I need to buy another bottle of the fancy expensive motul fluid I use and do a flush.

Wow, you guys are way ahead of me. I'm still using the hand operated vacuum pump:)

sweet momma...i have a vaccuum pump so i could arrange a little pump like that as well? do you have someone pouring in the master cylinder while your pulling the fluid through the caliper?

 

dude, all that takes is some line and a catch can....awesome.

Wow, you guys are way ahead of me. I'm still using the hand operated vacuum pump:)

 

And your ahead of me, i use my best freinds foot

 

nipper

man.....i still gravity bleed all my brakes....works well...why change?

Suck the master cylinder dry refill and either gravity bleed if possible or the old somebody in the car pumping method is what I do. There are brake flush machines out there now that do all the work for you. Expensive but they do work well. Shops that carry BG products usually have them.

There is only one option. The Motive Power Bleeder (50 Bucks). It a pump that enables this to be a one person job. Worked like a champ

boo pressure bleeding. Vacuum theoretically will do a better job at removing any air in the fluid.

 

Check out the pressure bleeding dos and don'ts near the bottom of this page:

 

http://www.stoptech.com/tech_info/wp_brakefluid_1a.shtml

I want the 10 minutes back I spent reading that article. I see the point but its only 10 PSI for a brake system thats 10 years old. It was under pressure for 15 minutes tops. The fluid that came out was the color of dirty motor oil. When I was done I did not have any air in the sytem. I must add the brakes are much better now