This DIY is a spinoff from
http://www.bmw-m.net/TechProc/bleeder.htm on how to hack an ordinary pump-up garden sprayer into a pressure brake bleeder. I procured almost everything and was ready to proceed, but found the garden sprayer more useful as a micro pressure washer and didn’t have a more pressing need for a brake bleeder.
I did, however, use the principle of the DIY to devise a pressure brake bleeder using items found around the house and/or rescued from the trash bin with just a minimal cash outlay for items you (may not necessarily) have to buy. This is NOT an inclusive "breath-in, breath-out" writeup detailing the most minute details and is intended primarily to provide ideas and a place to start.
Also, the usual disclaimer applies in that I am not responsible for how you use this information and do so at your own risk. :cool:
First, we will need fittings of some sort. Below are a few examples of “barbed hose fittings” which can be purchased at most hardware or home improvement stores. The item on the upper right is a discarded valve stem…
I wrapped tape around the threaded end and chucked it into my drill press, then used a small rasp to remove the rubber section and followed up with coarse sandpaper to arrive at the final finish.
You may elect to cut off the top of a valve stem cap to secure the modified nipple to your bleeder jar cover.
Another option is to use an old brake bleed valve. Cut off the pointed end and secure to the bleeder jar…
Here’s the top view of what my first version looked like using bleed screws…
Here’s the bottom view: on the left a plastic nut is securing the bleed screw that will be used to apply vacuum/pressure; the right fitting is secured using a compression fitting in which a plastic hose can be pushed into and held.
The plastic hose I was using would curl over time after contact with fluids and not touch the bottom of the jar, so I used a section of copper tube on the end that will sit in the fluid.
Our finished product with a piece of copper wire used to hang the jar from some point on the car. I chose a glass jar somewhat shallow, but with a large neck so I would be able to easily reach down inside for cleaning.
I used another valve stem and modified a GM master cylinder cap (Help! P/N 42035) following the instructions from the DIY.
On the underside of the cap is a groove that requires filling prior to pressurizing the brake system. I used blue RTV to fill it and in addition, used a rubber gasket found in one of my "20 year boxes" that fit perfectly. The rubber gasket may not be necessary, but I felt it would seal the cap better than RTV alone.
Now we’re to the meat and potatoes of our project.
Wear correct and proper personal protective equipment (PPE) (most of all EYE PROTECTION) and do not use excess air pressure which may cause the glass bottle to fracture.
Fill the jar with brake fluid, attach the cap to the reservoir and pressurize the jar using a low pressure regulator. You will only be using ~15-25 PSI !!
Note: Ensure you attach your lines to the correct fittings. If the lines are reversed the fluid will not transfer to the brake reservoir and the vehicle’s brake system will be filled with air. (See next picture for a visual)
Here we are mocked up and ready to pressure bleed our brake system. Note the hose connections as I mentioned in the previous picture. The regulator pressurizes the jar forcing fluid up the copper/plastic tube and into the brake reservoir. The regulator I used was purchased at a local chain home improvement store for $14.00, but there is an alternate pressure source that does not require an air compressor…
A simple bicycle pump will suffice and in my case…
…I used another modified valve stem…
…to connect to our brake bleeder! Pump it a few times and continue as normal. :0)
There are more uses for our DIY brake bleeder.
Before beginning your brake bleeding maintenance, connect a vacuum pump to evacuate the reservoir of old, nasty fluid.
Uh-oh! Did someone strip out the drain plug on the differential? Let’s connect a vacuum bleeder to the jar and evacuate the fluid…
Fill the jar with proper fluid and pressurize to service the diff. Since differential fluid is very thick, I recommend fittings with larger inner diameters such as 3/16” for this job. Using the bicycle pump may take forever, but it will tone your biceps. ;0) Use the same procedure for servicing the transmission.
There you have it! Inexpensive and you can even fabricate a couple of jars of different sizes for various tasks, fluids, etc. I hope this reads easy enough to understand and in that vein, I welcome and appreciate feedback and other ideas that I would/will be happy to edit in.
Topic: DIY Brake Bleeder (Read 12064 times)