FOUR UNCLES 2L Brake Bleeder Vacuum Pump Kit - Pneumatic Brake Fluid Extractor with 1L Refilling Bottle for Automotive Bleeding, One-Person Operation

I bought this device to flush the brake fluid in my BMW 540, and it made the job easy to do by myself—no need for a second person to pump the pedal. The instructions were clear, and the build quality is excellent; everything feels solid and well-made. A few tips for first-timers: • Air Compressor Needed: You’ll need an air compressor (I used a 6-gallon one), which isn’t included. Make sure the tank is dry before use. • Reservoir Attachment: Attaching the fluid bottle to the reservoir is simple; just make sure it’s stable. • BMW Owners: If your master cylinder has a hard-to-remove dirt filter, use the included thin nozzle to extract old fluid. • Bleed Valves: You only need to open the bleed valve about a quarter turn. • Output Jar: The volume markings aren’t super precise. I put painter’s tape on the jar and marked my own levels to track how much I’d flushed. The device worked perfectly, and I flushed all four calipers (some with two bleed valves) without issues. It took about 1 liter of DOT4 fluid for the whole job. The process is slower than manual pumping, but it’s much easier and more consistent. In summary: This brake fluid flush tool is a great value and feels over-engineered in a good way. I’d definitely recommend it to anyone looking to do their own brake maintenance. Just remember to get a compressor and check for water in the tank before starting. Good luck!

Works fantastically! This makes flushing brake fluid so much easier I might actually do it! The only comment I'd offer is that you definitely want to increase the PSI of your air hose as much as you can and get the biggest compressor you can, as this is pretty "greedy" for air.

This product works great and makes one person brake bleeding a breeze. I did encounter an issue with the guick disconnect coupler where the bleed hose connects. The quick disconnect had a bad o-ring. The photo shows the damaged o-ring. I was able to remove the o-ring and finish the job. I reached out to Four Uncles and they quickly responded and are sending a replacement. Things happen sometimes and I'm very satisfied with Four Uncles support and offering a replacement. I highly recommend this product. The included fill bottle didn't mount to the master cylinder very well, bit it still came in handy for a "mess free" option of adding brake fluid without spilling. Updated 7/7/25 - The replacement was received with in 3 days from Four Uncles. Thier Customer Support is outstanding!

The regular maintenance schedules, on my new cars, recommend a brake fluid flush every two years. As with any issue, I needed to be educated on the whys and how. Brake fluid is hydroscopic (attracts water). Brake fluid has a high boiling point. As it attracts water, the boiling point of the brake fluid decreases. Too much water in the fluid can cause poor brake performance, corrosion of the system, and failure. Next, I bought a brake fluid tester to see if my cars needed a fluid flush. Both cars were in acceptable ranges, but, after doing rear brakes on my son's truck, we noticed that his truck was at a dangerous level. Thus, the next step as to how to flush the system. I noticed two variants of flush tools. One variant pressurized the reservoir, and the other kept a feed at the reservoir and used suction at the brake caliper bleed. I thought that the pressurized version had more chance of introducing air at the reservoir, and the suction was the preferred method. After investigating the suction tools, the Four Uncles tool appeared to be the best adapted to my expectations. The tool was straightforward to use. The reservoir feed worked properly and the suction at the caliper was sufficient. The bleed does take some time to do properly. I did use more fluid than probably necessary. One thing I learned, after a couple wheels, was to empty the captured fluid. The fluid drained was dark. The new fluid was clear. When the old and new mix, you cannot tell when you are fully clear. Overall, the tool made the job easier, and I understand fully, after seeing the dark fluid drained, that the flush is needed.

I work in a shop and this the best vacuum bleeder I've used so far. Use it at twice a week if not more. I like that it holds large capacity can do a complete vehicle without dumping. Quieter then some I've used. Does the job.

This is a good brake bleeder but before you use it I teflon tape all the treads on this unit it leaked a little air and it also needs a lot of air to operate I’ve got a 50 gallon air compressor and set it to max out put 135psi then it worked awesome it looks like there’s air bubbles when hold the trigger down but one I let the trigger go it holds suction that the reason for teflon tape you can see the air bubbles come out and see straight clean fluid

Works great nice construction easy to empty

The suction is not that great but still do the job.

Excellent quality