Blogs Car Info Our Show Deals Mechanics Files Vehicle Donation

Bleeding brakes with vacuum

Another post inspired this question. I’ve had some luck with vacuum bleeders, but not a lot. I like to use them to pull as much fluid and air out as I can before bothering my wife to help. My cheap vacuum needs replaced. I am looking at a mighty vac for about $50. The documentation says it has adapters for cylinders and calipers. I’m thinking these adapters are screwed into calipers in a way that would allow a seal at the threads and allow fluid to be vacuumed through. Then I’d just remove the adapter screw and replace it with the bleeder screw. Does this sound feasible?

I found it was enough to dab a little bit of petroleum jelly on the bleeder threads (externally, no need to unscrew it) to make it seal enough for a $15 Harbor Freight manual vacuum pump to do its job with no external help altogether.

1 Like

Harbor Freight (among other vendors) has a version where you hook your own air compressor up to the gadget and that somehow creates the vacuum to pull the brake fluid out. Guessing they use the Bernoulli effect, the air flow from the compressor creates the vacuum. No need to pull on that trigger on the mighty vac. Suggest to check that version out to see what sort of adapters it comes with. Never used such a gadget myself, but it looks like it would be a little easier to do the job . I mean if you already have an air compressor. If you can figure out a way to secure a pressure bleeder system, imo that’s the better brake bleeding method. Probably better in the long run to spend a little more for that version.

No one seems to believe me but I will again recommend attaching a snug fitting piece of rubber hose 4" + to a bleeder and pointing upward with the bleeder just loose enough that it will flow, then while paying close enough attention to the reservoir that it never runs empty pump the brake pedal until liquid flows out with no bubbles then move on to the other wheels. It’s faster than vacuum bleeders and faster than using a helper even when allowing for sweeping up the oil dry left on the floor to soak up the fluid.

1 Like

They sell many types of vacuum pumps, I have a Mityvac MV6830. The brake bleeder adapters that came with this unit are just 90 degree rubber boots that slip over the bleeder screw nipple.

That’s probably what’s in the one that I looked at. I like the idea of the one that uses air, but I like the hand ones because it doubles as a vacuum source with a gage and don’t want to put that much more money in. I was hoping that there was some new innovations out there that I missed for cheap money. Thanks for the tips.

your method works great if system has no air, otherwise some “persuasion” is still needed

I used this one:

it worked great for brakes, then at the point I needed to make vacuum in the system when replacing the the coolant, I made an improvised rubber adapter and it took under 5 minutes of pumping to generate enough vacuum to fully re-charge the system in 6-cylinder Nissan Pathinder. Definitely beated the time to get to the store for the “proper tool” :slight_smile:

I use a method similar to Rod Knox but use longer tubing to a jar mounted above the bleeder and I put enough fluid in the jar to cover the end of the tubing. this takes slightly longer than Rod Knox’s method but not if you count the time cleaning up the brake fluid.

I have that one. Has pretty much any adapter you need for the m/c bottle. Works very well, actually, and surprisingly for Harbor Freight, has lasted me something like 15 years.

Harbor freight scared me, but maybe I’ll check it out today. I’m going right by there later.

Don’t forget your 20% off coupon, and free item coupon. In my area these come in the snail-mail advertisements each week.

To this day, my father and I use a jury-rigged bleeder consisting of a hand-held vacuum pump, a couple lengths of plastic tube, and a tall mason jar with two holes drilled in the lid and sealed with duct tape. Open the lid, put a little brake fluid in, close the lid tight, and start working on the brakes.