Electric Vacuum brake bleeder etc

[Motofixxer]

For years I have been bleeding brakes with my little Hand vacuum pump, or the help of another foot to pump. Well I decided to change that. So after a little research and a little fabrication this is my result. I didn't want to put a lot of $ into it. But I did want it to be very functional. So for a basic description it's using a plain old $20 tire inflator which was modified with some epoxy and a 1\4" hose barb to cover the intake of the inflator pump. Then some plain old 1\4" ID rubber hose, a couple of hose barb fittings. Then finally a "watertight" container I found at my local wally world in the camping accessories. The inflator is not permanently modified and still works perfectly. I did put one of the included straight through nozzles in the inflator tire valve end to permit the air exhausting from the inflator outlet hose. Another idea is to cut the whole valve off and leave the hose bare. But that would permanently modify the inflator. My hand vacuum is connected by hose and Tee to view vacuum, also not permanently modified. And finally the container which may need modification, but esentially works. One barb epoxied into the top cover, which actually needs to get swapped for a screw in type fitting or tire valve drilled out to 1\4". The other line is simply 1\4" brake line with an angle cut on the bottom to permit flow while sitting on bottom of container. Then epoxied through container cover with hose attached with a clamp to tighten the fit. The brake line needs to be changed to run through the center of a drilled out screw in tire valve etc, because of vacuum leaks after a while through the epoxy in the lid. The container might need to be switched at some point to a stronger one because the top actually flexes in a fair amount at full vacuum which appears to be about 23". The setup actually works faster than I thought it would due to the larger container. And it has a fairly large capacity with the container. But its pulling vacuum almost immediately and can easily maintain a strong vacuum while bleeding lines etc. I have started thinking of all kinds of uses for this now such as evacuating floor jack oil, differential fluid changes, brake \clutch bleeding, P\S fluid changes. I think I will be using it much more now and maybe you can think of more ideas or improvements for the idea.

 

[tonydanzah]

that is a pretty well thought out setup

 

[Motofixxer]

Thanks, I have been trying to come up with a solution for lets just say a long time. The most expensive part was the container for $9. I have had the inflater for years sitting in the truck for emergencies. And I like the idea that nothing is permanently modified. It's simple yet very useful.

 

[russlaferrera]

I use a/c or refrigerator compressors. All are free.

 

[IMCA38]

I picked up a working uterine aspirator for $3.00 when a local vet closed up his practice and auctioned everything off. This thing makes an awesome brake bleeder.

 

[tonydanzah]

Did you originally buy it for that? Seems like an odd purchase.

 

[Motofixxer]

I heard of compressors being used, but the first time I heard of a uterine aspirater. I don't know if I even know if I want to know what they are used for.

 

[yhprum]

Good idea, using the compressor!.I made a similar tool using a large glass jar, except I still use the hand pump to create the vacuum. I have thought about just plugging it into a vacuum port on the engine and let that create the vacuum in the jar. Steve

 

[Motofixxer]

I considered using a glass jar but didn't really like the idea of a jar floating around just waiting to break...then with filled with brake fluid as well. I wanted a plastic container if possible.

 

[IMCA38]

Did you originally buy it for that? Seems like an odd purchase.

Actually, I bought it because it was on a nice heavy table with a drawer on wheels, and it only brought $3. This was back when I raced and I figured that I could mount the readout for my electronic wheel scales on top, store the load cells on the bottom shelf and have a drawer to keep pens, set up sheets, etc in. My crew chief at the time saw it and said "Wow, I bet that would work good to bleed brakes." We tried it and it did work well. The scales never did get a cart.

I heard of compressors being used, but the first time I heard of a uterine aspirater. I don't know if I even know if I want to know what they are used for.

I'm not sure why they are compelled to attach the term "uterine" to it. Vacuum cannisters like this are pretty common in medical-type settings. I remember when my dad was a volunteer EMT, they had a similar deal mounted in the ambulance to **** up blood, barf, etc. Its just a vacuum pump with a couple of catch jars mounted in line. I'd hate to think what one might cost new!

 

[Motofixxer]

Learn something new everyday I get on here

 

[russlaferrera]

I considered using a glass jar but didn't really like the idea of a jar floating around just waiting to brake...then with filled with brake fluid as well. I wanted a plastic container if possible.

I use a canning jar. It has lasted 8 years. They are heavy duty. I'm not sure if plastic jars will hold up to brake fluid.

You could use some 4-5 in pvc pipe as an outer cover to protect the jar?

 

[IMCA38]

I considered using a glass jar but didn't really like the idea of a jar floating around just waiting to brake...then with filled with brake fluid as well. I wanted a plastic container if possible.

Mine has glass jars, which I'm less than fond of. But overall, it works OK as the jars rest safely in a rack on the side of the table and the suction hose is long enough that I can reach whatever I need to. Therefore, the only time I have much risk of breaking something is when I take them out of the rack to dump them. I have to say, the glass is nice as far as being able to clearly see what you're sucking out and how much debris is in it.

 

[galwaytt]

...you've prompted me about an idea I've had for ages, but I sold the bike I planned it for, and the idea has been temporarily 'shelved'.......

Good call on the small pump as vacuum generator, I believe you'll find specific elec vacuum pumps under the bonnets of some diesels, and definately under the bonnets of electric cars too (no spinning crank to put a belt on, to generate vacuum for brake servo's, see ?? ).

Anyhoo, brakebleeding can be a pest at times, and I've found on bikes that have very small fluid volumes (e.g. GasGas trials bikes), that you need to drive fluid up from the lowest point, usually through the bleed ******. Usually I use a v.cheap 60cc syringe and a piece of tubing. Eventually, the brake fluid reacts with everything, but it's only 1.00 invested, so no biggie !

Anyhoo, working on the BMW R1150RT, which uses a dual circuit, elec power assisted brake system, some things came up. First, the master cylinder fluid NEVER reaches the wheels - it's only a control circuit, attached to the ABS pumping module, with a fluid pressure transducer in it. As you apply pressure through the brake lever, the pressure transducer, via the ABS ECU, interprets how hard you're braking and then uses the ABS pumps to pressure feed the wheel circuits, with it's own, separate fluid reservoir, as required. You can imagine, therefore, that brake bleeding takes on a whole new dimension. But, actually, it's easier ! Yep, essentially, you unscrew the cap of the wheel cylinder circuit on the ABS unit, and screw on a plastic 'funnel', containing, say, 500ml of fluid. Then you crack open a bleed ******, and apply pressure to the brake lever (very little required), and hey-presto, the ABS unit PUMPS fluid to the now-open ******. Leave it open 'til fresh fluid appears and Ta-Da - you're done ! Repeat 3x (3 calipers !). 15 minutes, all done ! A conventional system is a complete PITA compared to it !

Which got me to thinking...........that's how factories bleed their systems - they're pump filled from the calipers up..........no bleeding required !

Which got me to thinking even further !.............now, how to build a DIY brake fluid-filler, with 12v..........easy, the scrapyards are full of cars with.....12v ABS pumps ! All it takes is, like the set up above, a cigarette-lighter lead (or croc clips...they're all 12v, remember...) with a little push switch, the pump unit and reservoir for a volume of fluid (1 pt/500ml sounds nice and conventient...)....and you just a tube to push on over the bleed ******, or splurge on a fitting to screw in, in lieu......and there you go: DIY brake fluid pressure filling system with all-compatible parts that won't corrode ! And no pressure cylinders or vacuum cylinders to leak - the fluid is at atmospheric !