Bleeding Brakes - Gravity Bleeding

[mechtech2]

Gravity bleeding will get air out.
There is no reason to think that more pressure will get more air out.
The solid column of fluid is what purges the system.

 

[Eddie]

Pressure bleeding forces the BF through the system much faster. The flushing effect causes some turbulance which can remove air from small pockets.

 

[sciphi]

I still need to bleed my brakes. That old fluid looks black and nasty.

I have the little Harbor Freight vacuum pump. It works pretty well. Only downside is the tiny reservoir. That gets emptied pretty regularly.

 

[Aldaris]

Originally Posted By: sciphi
I still need to bleed my brakes. That old fluid looks black and nasty.

I have the little Harbor Freight vacuum pump. It works pretty well. Only downside is the tiny reservoir. That gets emptied pretty regularly.
Can you post a link to the product? (I know it might be a pain but I'd appreciate it)

 

[The Critic]

Originally Posted By: Aldaris
Originally Posted By: sciphi
I still need to bleed my brakes. That old fluid looks black and nasty.

I have the little Harbor Freight vacuum pump. It works pretty well. Only downside is the tiny reservoir. That gets emptied pretty regularly.
Can you post a link to the product? (I know it might be a pain but I'd appreciate it)

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=37201

I paid $5 for mine. I'll try it out this weekend and report back with the results.

 

[Aldaris]

Cool, thanks. I remember buying one of those from Pep Boys back in 2002. I wasn't able to get it working well and tossed it. (I was probably doing it wrong)

 

[SZR48207]

Is that just a bottle that you attach to the bleeder valve? I wonder if it has some sort of one-way pressure valve so you can pump the brakes without sucking air back into the lines.

 

[Audi Junkie]

Originally Posted By: moribundman
Originally Posted By: Audi Junkie
I said my part and never had a problem draining the systems fully.


In case of your B5, how'd you get the fluid out of the ABS control unit without cycling it?



What makes you so sure there is fluid in the ABS controller after it's drained?

I leave all the bolts cracked a hair and let it bleed very slowly until it stops spitting out little bubbles. Close them and I'm done.

 

[moribundman]

Originally Posted By: Audi Junkie
Originally Posted By: moribundman
Originally Posted By: Audi Junkie
I said my part and never had a problem draining the systems fully.


In case of your B5, how'd you get the fluid out of the ABS control unit without cycling it?



What makes you so sure there is fluid in the ABS controller after it's drained?

I leave all the bolts cracked a hair and let it bleed very slowly until it stops spitting out little bubbles. Close them and I'm done.


I doubt you can gravity drain the ABS control unit fully since it contains valves. Just because a system doesn't leak any fluid any more, doesn't necessarily mean that no fluid remains. If you were able to drain the ABS control unit completely, you might get a serious problem with trapped air. Maybe a new ABS control unit comes prefilled with brake fluid? This would be an indication that what I'm suspecting is correct. I could be totally wrong, though.

 

[Audi Junkie]

What do you guys do when you change a caliper or a line?

 

[bdcardinal]

Originally Posted By: Audi Junkie
What do you guys do when you change a caliper or a line?

if i was replacing the caliper i would clamp the line, and change it, never had any problem with that whatsoever. if i was changing a line, i would have the auto filler on the master and just change the line fast, again, never had a problem.

 

[moribundman]

Originally Posted By: Audi Junkie
What do you guys do when you change a caliper or a line?


I plug the line.

 

[The Critic]

Originally Posted By: moribundman
Originally Posted By: Audi Junkie
What do you guys do when you change a caliper or a line?


I plug the line.

With what? An earplug?

 

[moribundman]

I use a pinkie.

 

[moribundman]

Seriously, there are hose plugs. You could probably even use a golf T (round the point off) etc et al.

 

[The Critic]

Where can I buy them? The guy at the local parts store thought I was nuts when I asked for line plugs.

 

[moribundman]

If you are unable to macgyver a couple plugs, go to your FLAPS and look for vacuum hose plugs. I know PepBoys has them.

 

[Volvohead]

Originally Posted By: Audi Junkie
What do you guys do when you change a caliper or a line?


I'll plug and then bleed just the affected corner, to flush out any manufacturing contamination from the new part(s) or that may have gotten into that branch from being opened.

But normally, if I encounter a bad caliper, I don't reuse pads, I'm then dealing with both sides on that axle, so I usually replace both calipers and bleed the whole system to be safe and assure balanced performance. You're already doing most of the labor on the other side, so the extra parts cost is no big deal.

You can't be too safe when dealing with braking systems. Especially with the pie pan rotors they put on them these days.

 

[glennc]

Originally Posted By: The Critic
With what? An earplug?

That's funny. I was flushing my power steering earlier this week and needed something to plug the reservoir input so I could run the line to a pan. I used an earplug and it worked very well.

 

[mechtech2]

If no one is looking, you can clamp the rubber brake line, also [use rounded pressure pads].
And yes, I know this in not recommended by the manual.