Homemade brake bleeder for bail top master cylinders?

For every modern vehicle I own, I purchase a new brake master cylinder cap, which are always plastic, to build my own bleeder system. I drill a hole in the plastic cap, install an air hose quick disconnect pressure fitting (same one you use on standard air hose) using O-rings, and then put about 20psi on the master cylinder. With 20psi on the master cylinder I can start bleeding like normal without having to need a friend pump the pedal. I go to the right rear, crack bleeder and allow it to flow clean, and then do each wheel until done.

Heres the problem....

I also have older cars/trucks with bail top metal caps. Is there any reason I couldn't install a pressure fitting in the metal cap and do the same style bleeding with the metal bail clip master cylinder cap?

 

With this set up you need to make sure the air is mositure free.

 

Yes, make up a 1/4" thick steel, or alum. plate to cover the master. Drill and tap for your air lines to attach. I made up a couple of U bolts out of 1/4" threaded rod to attach the plate to the master, with a piece of 1/8" thick rubber as a gasket.
If you have patience, or machines, I'm sure you can machine a lid that will even use the stock wire to hold it down, but I like to think the U bolts are stronger.

 

Applying pressurized air directly to brake fluid is exactly what you DON'T want to do. What's worse is contaminated (oil/moisture) air out of a compressor. Cheap and easy on a brake system is seldom a good idea, and this is one of them.
If you're going to pressure bleed, use a proper brake pressure bladder, or simlpy pedal bleed.

 

Why couldn't you?

 

I simply run a hose that fits snuggly on the bleeder and run the hose into a jar with brake fluid. You simply open the bleeder and pump the brake until you stop getting air bubbles and then close the bleeder. We did this in the old days and it still works and you don't need an extra person. Don't forget to keep an eye on the fluid level in the MC and always start on the wheel farthest from the MC.

 

I just drill a hole in the metal and install a rubber tubeless tire valve .......................................

 

...you must have long legs or x-ray vision to do this yourself...LOL.
How do you know when you're not getting air in the bottle?
..also, if you don't close the bleeder after the pedal is down, you can suck air back into the cyl.

 

The other end of the hose gets submerged in brake fluid that you put in the bottom of the bottle. Nothing gets sucked back in. It's really more a "trial and error" sort of thing. You keep going until you're sure there's no more bubbles.

 

Combination would be best.
Make the top plate as described above and connect it to a fluid reservoir

Pressurize the reservoir so it pumps pressurized brake fluid into the cylinder.

Best of both worlds, plus you don't have to worry about filling the M/C as often.



I've did this years ago at the track when I would boil the brake fluid in my Audi Brakes. Someone made a really simple pressurizer out of a bug sprayer, the kind with a pump handle on top adn the hose out of the bottom going to a spray nozzle. Fill the sprayer with Brake fluid, connect it to the Master cyl, pump it up and go.

Google searched to find the pic

 

That's exactly what I did except I don't put any fluid in the sprayer. I just use it as a portable and uncontaminated source of air pressure. I use clear vinyl tubing, installed a shut off valve and a pressure gauge and connect it to a fitting I installed in an extra MC cover. Cheap, easy to use, and I can bleed the brakes on my '58 in less than 10 minutes...by myself.

 

Been doing it this way for 30+ years. LIke he said, you put a small amount of fluid in the catch jar, and loop the flex line, so that air isn't sucked back into the system. I usually just get on one knee, look under the car and pump the pedal with my hand. I usually use plastic pop bottles, so that I can screw a lid back on them.

 

The whole idea for using the tank like Flt-blk showed with brake fluid in it is so that you DON'T introduce air back into the brake system. Just putting air to it leaves too big of a chance of putting air back into the system along with contaminating it with moisture i you use the air hose off a compressor.

That tank setup can be made for under 20.00 bucks by picking up a gallon spray tank at Ace or another hardware store. Then make your own top or modify a spare top like some of the guys mentioned above.
Easy to follow instructions here http://www.bmw-m.net/TechProc/bleeder.htm I think he was the original one who did it and even the aftermarket boys copy his and add big bucks to the cost.

 

i use the tube and bottle trick. but this pressure deal looks good.

 

The whole idea for using a "bug sprayer" is trying make a $150 or so brake bladder pressure tank for $20, which it dosen't. A "real" brake bleeder keeps the fluid completely isolated from air at all times. How can pumping air into a cheap sprayer filled with brake fluid NOT introduce air/moisture into the system?

 

...I use the clear tubing and plastic pop bottles too, I was wonderin if air could get sucked into the wheel cyl. at the loosened bleeder....guess you just crack it open a little as needed.

 

True it would work better with a bladder between the air and the brake fluid than with the 10.00 weed sprayer but the 10.00 weed sprayer is going to take a lot lest moisture out of the air than the shop compressor will.

the main things with keeping moisture out of stored brake fluid are to always keep the fluid in a sealed container and don't buy more brake fluid than you can use in a set period of time. Only brake shops that are doing five or six or more brake jobs a day need to keep five gallon cans of brake fluid around and for most of us at home gallon cans are pushing the limit on what we will use before it might draw moisture. How many times have you walked a shop and seen a gallon of brake fluid sitting on the bench or shelf either without a lid or missing the lid or with one of those pump things stuck in it that pretty well leaves it open to the atmosphere.

I'd much rather have fresh fluid where I can see it in a small pressurized jug connected to the master cylinder so that I can slide around under the car and quickly bleed the brakes than either try to hook an air hose directly to the master cylinder cap or have to wait until I have a helper to get the job done.

And not every one of us has an extra 150.00 laying around so we can have a "real" pressure brake bleeder to do that maybe one on the average brake job a year at home.

 

i have done what the original poster says, works very well, only thing, 20lbs of air pressure, how did you get away with that? i put like 5lbs and shit was trying to blow up.......and i think the amount of moisture you might put into the system would be measured in zero to marginal at worst, doubtfully enough to cause a problem in any of my very well maintained vehicles.....but thats my opinion.....

 

none of ya's use speed bleeders?

insane, they're the only way to bleed out a system.

http://www.speedbleeder.com/

 

how do you maintain the inside of a brake line, caliper or cylinder? this is wisdom i really need to obtain. once a little bit is in the system, its there dude...

 

Silicone brake fluid. Doesn't absorb moisture, and if any moisture DID get in, it wouldn't do a thing. In order to form rust, you need to combine the moisture with air...and if you have air in the system, you've got other problems to worry about. Besides, silicone fluid doesn't eat away paint...FWIW.

 

ain't them like $70-80.00 a set?

 

It's much better to simply pedal bleed the brake system rather than spend time fabricating a cheap P O S "bug sprayer" bleeder if a correct bladder tank is too costly. You do NOT want to pump air into brake fluid, something many obviously do not understand. Use your creative talents saving money on other less important/critical areas of the car, not the brake system.

 

are any of these blader bleeders?

http://www.jegs.com/p/Motive-Produc...rake+bleeder&gclid=COXJ5v2lxKcCFQ1ggwod0TXZCQ

 

tell that to the skipper of the titanic. . .

not even close... try $8-10 a wheel. dont buy the brand name... go to carquest and ask for the "self bleeding style brake fittings", make sure to know the thread, cause unlike any other thing in the store, they arent car specific in the computer... amazing, even asked one time what kinda car i had when i asked for a case of 10w-40 oil. i just stared at the kid and blinked ... anyhow, they're made by the same outfit but just come in a generic blue carquest box

 

I think people are getting a bit to worried about 'water'. Do you put the brakes together in a humidity free room? If not you have water in your brakes lines and cylinders/calipers.

Better not take off the fill cap on a wet day or the brake fluid be screwed.

 

You're right. 20 lbs is WAY too much. With my "POS Bug Sprayer" I use about 5-6 lbs max.

Oh yeah, contrary to what some folks may think, it seems to me you're not "pumping air into your brake fluid" as long as you don't let your master cylinder reservoir get too low. It just pressurizes the system and makes it easy to bleed. I don't have any air in my system.

Takes me about 10 minutes by myself, to bleed each of the systems in my '58s...firm pedal...no air...no moisture...no problem.

 

Problem is that glycol brake fluid absorbs the water out of the air over time. That is why you need to have your container sealed, to stop the continuous supply and absorption of water. Corrosion is part of the problem but water boils when it gets hot, Your brake fluid is not supposed to boil so no water allowed. That Jegs link had a brake fluid moisture analyzer, I never knew they made such a thing.

 

If you all are worried about water getting into the system, why not use Nitrogen from a tire or rig the fittings and use your MIG or TIG gas??

(I know, nitrogen is not traditional and we should hammer weld, but just sayin'.........)

 

hey, fiddy four, yeah, i maintain all that, by replacing the fluid semi reguarly....alot of guys act like the rust in your brake system will occur overnight.......i would say even the manufacturers recomnd replacing all the brake fluid yearly.....plenty often, even if oyu get some moisture in the ssystem, which is gonna happen, unless you assemble the car in a vaccum, and, come to think of it, leave the car in the vacuum forever....maybe hot rod on the moon.......i think most of the caps on most of my cars are vented, so.....theres moisture in there...like it or not.....