veltboy618

I changed my wheel cylinder today & now I need to know how to get the air out of the line. I'm going to have someone to press the pedal but I need to know how to do the rest.

csstrux

There will be a bleeder screw on the back side of the cylinder poking through the dust cover. Likely a 3/8 or 5/16 head. Have your helper pump the pedal three times and hold on the third pump. When he has done that release the screw, hold it cracked until everything that will come out does. Close the bleeder up. repeat until fluid runs clear (no bubbles) best to start closest to the master and work your way to the farthest. You probably wont need to do all four corners, but is a good habit.

jensenracing77

the wheel cylinder has a bleeder at the top pointed to the center of the car. with the brakes and drum on have someone pump the brakes 4 or 5 times then hold them. next you will want to turn the bleeder about a half turn then tighten it. now repeat till all the air is gone. just don't forget to add fluid to the master cylinder.

jensenracing77

you beat me chad

OLD SKL 69

Also, make sure that if you do all four wheels, make sure to add fluid to the m/c after you bleed each wheel. You do not want to run the m/c dry otherwise you will have to do it all over again.

dan2286

Isn't it best to start from the farthest away and work up to the closest?

ent72olds

Yeah, I think Chad meant "closest to the farthest spot!"

OLD SKL 69

That's the way I have always done it too.

FATRATMATT

Just a thought.... I always prep my Bleeder screws BEFORE I start wrenching on them. If they are older and haven't' been opened recently I spray them down with PB Blaster the night before. The last thing you want to do is bust a bleeder screw. That could ruin your day real quick!!

Olds64

Make sure you use a new bottle of brake fluid. It is very hygroscopic and if you have an old bottle sitting in your garage chances are it has too much water in it.

FATRATMATT

I remember helping Dad when I was a kid. He would yell "PUMP IT UP" followed by "HOLD" and then my response would be "FLOOR" For when the pedal would drop, and then the process would start all over.It's funny how a question can bring back such fond memories

veltboy618

thanks guys. i think i read somewhere that I leave the top off of the matser cylinder. Is that true?

FATRATMATT

Yes that's correct.

veltboy618

I tried it earlier with the top off & i shot brake fluid everywhere

FATRATMATT

I've never seen fuild shoot all over the place, I'll get some that will run over the sides as the fluid is pushed back thru the system. Have the (pumper) lighten up on their pumping. Dad would tell me to push not pump the pedal. Slow steady pressure should be plenty.

veltboy618

Thanks for the help!

hamm36

Why would you do it with the top off during the process ???

OLD SKL 69

If you try to bleed the brakes by leaving the cover off, it will make a mess. When the level is high, it will overflow down the sides. When it gets much lower, it can shoot out in a stream.

I fill the master to the top, put the cover back on, bleed one wheel, open it up again and refill it and repeat the process. It may take a little longer, but it has always worked for me and it makes for much less of a mess.

FATRATMATT

I never have a problem bleeding with the top off. I have a small pan that is shaped like a loaf of bread that fits perfectly under my master cylinder, what spills over the top is minimal. Wipe it off with a shop rag and done. works both ways. To each his own I say.

csstrux

It may not be correct, but it was the way I remember my Dad and I doing it growing up, and the times I had to do it was from the closest to the farthest. If I remember right the idea was to get as much air out of the lines as rapidly as possible, and then clean up what ever is left. It has been many years since I have needed to mes with brake lines, so this might be wrong for a complete system overhaul. Most of the work I did was at the front. Masters, soft lines bursting and such. There was one time with my 63 impala i just cracked the bleeders and let it sit for the day, topping the master off occasionally. Believe it or not it worked (had no help and was desperate).

sworthy555

Just don't get any brake fluide on your paint. It can do some real damage.

Olds64

This is very true. Brake fluid is probably the most caustic fluid used in a car. Make sure you wash your hands if you get brake fluid on them. It won't eat away at them like in the movies but it will irritate your hands quickly.

Also, make sure you get DOT 3 brake fluid. This is engineered for older cars with disc brakes. Whatever you do, don't get the purple brake fluid (I want to say it is DOT 5). This has a different chemical base and will destroy the seals in your brake system. It is used often in foreign cars.

Bluevista

I know the the traditional way is farthest to closest but the service manual says closest to farthest? With split systems it probably doesn't matter much anyway except for centering the warning light switch, probably why you have to bleed all the wheels?
I keep the cap on to be safe and just keep checking it, why risk a fountain of brake flluid and that stuff does eat through paint fast. I use a bleeder jar or vacuum bleed them with my mighty Mityvac, never have any help around (that I want).

veltboy618

how long does it take to bleed the brakes the gravity way

Olds64

I don't care much for the Mity-Vac or vacuum bleeders. They don't seem to work too well. Plus, it is super easy to bleed the brakes the old fashioned way.

csstrux

Correct me if I am wrong, but my understanding was that DOT5 is the hot shiz. I believe better heat resistance or something to that effect.The thing is that DOT3 and DOT5 if mixed become caustic, and will literally eat the entire system, I have never looked into this. The guy who did all the machining, and sold me most of the parts, as well as fixed all my mistakes on the Harley, told me something to that effect, and I took it as gospel. Assuming this is true, you would probably want to convert over if doing major work to the system. just make sure to flush any existing components thoroughly.

csstrux

I only did it once, and am not sure it will work consistently, but the car sat about 3-4 hours with the bleeders cracked just enough to flow, not run, but a steady trickle. All four corners may have been about 1.5 pints of fluid. Granted I did this back in '89 with a single reservoir system. Will it work on the new systems and is memory accurate

Bluevista

I made a Mason jar bleeder years ago, strain your neck bending over and looking under the car while hitting the brakes to watch the bubbles on those right sides.
The Mityvac works but the problem with vac bleeding is that it tends to pull air in around the bleeder screw threads and the hose fitting if everything isn't right. You have to have the button pressed in on the distribution block/valve or external hold-off valve. My goat will not bleed at all without the MC mounted disc brake hold-off valve button depressed, I made a tool to hold in both types like the book shows.

Joeypete

Can you bleed the brakes without having the whole car jacked up? I only have 2 jacks and really don't feel comfortable with the whole thing off the ground. Also the "pumper" person can do it from outside the car right? Not sure I'd want someone in the car with it jacked either...I know, I'm a worry wort! :P

csstrux

If you can get to the bleeder screws you are good. one end or the other is sufficient.

Joeypete

Cool...so you mean front or back is fine?

Olds64

When you bleed the brakes start with the wheel cylinder which is farthest from the master cylinder. Then work your way closer to the master cylinder. All 4 wheel cylinders need to be bled. You can jack up the rear and then jack up the front. No need to put all 4 corners up at once.

Jon69

I recently replaced the rear lines and wheel cylinders. The amount of time I spent trying to get the system bleed was as my wife put it "insane". You probably won't have this problem if you just put on a new cylinder, but if you have the means a power bleeder is a thing of beauty. Positive constant pressure from the master cylinder back is by far the simplest and cleanest way to bleed out the system, once….once.

I borrowed one to finish off my project but they can be had for about $75.
http://store.motiveproducts.com/shar...unt2=718879342
I will not open the system again without a power bleeder on hand.

Just my .50 worth.
YMMV
Jon