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Natural Aspirations

Which One-Man Brake Bleeder is Best?

by Roger

Which One-Man Brake Bleeder is Best?

Bleeding your car's hydraulic brake system is a fact of life for the mechanically inclined car enthusiast, especially for those of us who participate in track days, race, or enjoy a bit of spirited driving. Unfortunately, brake bleeding is a terribly boring task. It's so tedious that your closest friends and family will quickly learn to ignore your requests for help and you will inevitably be stuck doing this two-person operation by yourself. Believe me, I've been there.

Here's what I have from years of collecting and using one-man brake bleeder tools on cars of many different shapes and sizes:

 

Plastic Bottle Type

Cost: $6 - $20
Where to buy: AMPRO T71658 One Man Brake Bleeder (or literally any auto parts store)

Brake Bleeder Bottle

First up is the ubiquitous narrow hose in a tiny plastic bottle type brake bleeder. You can find this type at pretty much any auto parts store. Just plug this onto the bleeder nipple of your brake caliper, crack open the brake bleeder screw, and slowly pump the brake pedal. As long as the hoses going into the bottle are full of fluid, you can keep pumping without letting air back into the brake pedal.

The downside is that the bottles tend to be tiny (by design) so they fill up very quickly. If you are bleeding large brake calipers or are doing a flush of the brake system, you will be running back and forth to empty the bottle every 5 or so pumps of the brake pedal. The construction of the bottle also tends to be cheap, as are the rather hard plastic hoses which rarely do a great job of sealing against the bleeder nipple. If you use this type of brake bleeder bottle, expect to replace it once every few brake jobs.

Pros:

  • Cheap and universal
  • Works well for quick brake bleeding jobs
  • Available pretty much everywhere, so no worries if you forget yours at home

Cons:

  • Hard plastic hoses may not seal well against the bleeder nipple
  • Small bottle means you have to stop and empty the brake bleeder bottle often
  • Bottle is pretty fragile. Don't let this roll around in your toolbox or it will come out in pieces.

 

Inline Check Valve Type

Cost: $11 - $15
Where to buy: Motion Pro 08-0143 Hydraulic Brake Bleeder

The cheap plastic brake bleeder bottles are ok for quick brake jobs, but running back and forth to empty the liliputian bleeder bottle can get annoying if you have to flush out more fluid. While they do sell more expensive kits with larger bottles, there is a better solution.

This motion pro kit is basically a metal check valve between two pieces of flexible plastic hose. The one-way valve keeps the air from getting sucked back in while springy hose clamps keep a tight seal around all connections. Because the ends are open, you can also bleed straight into a catch pan or a larger bottle.

Despite its simplicity this design works well. Because the old fluid is retained in the hose, it's easy to step out and see the condition of the fluid as it leaves the brake caliper. The metal check valve shrugs off accidental drops and it doesn't seem to degrade over time like the plastic bottles. And if you do manage to lose or break it, it's still cheap to replace.

Pros:

  • Durable and portable
  • Lets you bleed directly into a larger container instead of going back and forth to dispose of fluid

Cons:

  • Check valve doesn't work well for bleeding clutch systems
  • Can't be used to bleed master cylinders

 

Speed Bleeders

Cost: $12 - $25 per pair
Where to buy: Speed Bleeders at BestBrakes.com

Another option is to put the check valve into the caliper itself. Speed Bleeders are bleeder screws with a spring-loaded ball valve built into the body. I've tried a few designs over the years (including some really crazy looking variants) and found that the original Russell Speed Bleeders tend to work the best and be the most durable.

The concept is that you unscrew your existing brake bleeder screws and replace them with these screws. When you bleed the brakes, all you need to do is to put a length of hose on the bleeder nipple, open it a quarter turn, and start pumping out the old fluid.

The biggest challenge is finding the right screw size for your calipers. If your car still has the OEM brake calipers, this shouldn't be an issue. But most aftermarket and rebuilt calipers come with larger brake bleeder screws than they had from the factory. In these cases, you need to measure your existing bleeder screws to make sure that you are ordering the right size. Still, this is a great option if you primarily work on one car.

Pros:

  • Set and forget - All you need is a length of plastic hose to bleed your brakes
  • Easy to use once installed

Cons:

  • Not transferrable across cars
  • Finding the right fitment can be a challenge with non-OEM calipers
  • Metal tends to softer than the OEM bleeder screw. Be careful not to over-torque when tightening.

 

 

Pull Type Vacuum Bleeder

Cost: $30 and up
Where to buy:

All of the tools that we've talked about so far do a good job of bleeding air and old fluid out of your brake calipers. But what if you let the fluid level drop too low and there's air in your master cylinder? Or if you need to change out the ancient fluid in your clutch hydraulic system? 

The tools we've talked about so far won't work in these cases. That's because they rely on force from the master cylinder to push out the old fluid. If the master cylinder can't produce enough pressure in the areas that need to be bled, you can't rely on them to effectively bleed the system.

Enter the vacuum assisted brake bleeder. These bleeders rely on vacuum to suck the fluid out of the hydraulic system, using either a hand-operated pump or a Venturi valve connected to an air compressor. I connect mine to a 21 gallon Harbor Freight compressor using the quick connect port on the grip. I have also used the manual pump ones and can confirm that they work just as well.

Because they are vacuum assisted, you can use this type of bleeder to bleed pretty much any hydraulic system including your clutch fluid or ABS module. You also have to do less work because you don't have to get into the car and push the pedal. Once the pump is attached and you are drawing a vacuum, all you need to do is sit patiently as all of the old fluid is sucked out of the hydraulic lines.

The one drawback is that your car's hydraulic systems were not designed to contain a vacuum. Using a vacuum bleeder puts stress on the seals in the master cylinder as well as the rubber brake lines connected to your brake calipers. Generally this isn't a problem, but if your car has older brake lines or if your master cylinder is older, vacuum bleeders can cause leaks. I learned this the hard way on an old Nissan Quest that had seen better days. Because of this, I tend to use vacuum bleeders sparingly.

Pros:

  • Doesn't rely on pedal pressure, so you can bleed master cylinders from the caliper
  • Can also bleed clutch hydraulic systems and some ABS circuits
  • No need to get into the car to push the brake pedal and risk getting brake fluid all over your interior

Cons:

  • Can cause leaks in old master cylinders and worn rubber brake lines
  • The manual pump models can be surprisingly expensive - more than the air compressor powered ones

 

Push Type Power Bleeder

Cost: $50 and up
Where to buy: Motive Power Bleeders Kits on Amazon

For those of you who need to do a full brake system flush and/or are worried about the condition of their seals, we have the push type power bleeder. This one is a Motive, and at $50 + extra for adapters, it is the most expensive brake bleeding tool in my garage.

Setting up the Power Bleeder is a bit more involved than with some of the others. First, you fill the power bleeder with fresh brake fluid. Then mount the bleeder to the master cylinder reservoir using either a model-specific adapter or a universal adapter like this. Then use the integrated pump to pressurize the master cylinder to 15 psi, attach a hose to the brake bleeder nipple, crack the valve, and wait. The bleeder will force new brake fluid through the system from the source and push all of the old brake fluid, along with any air, out of the bleeder.

Because these power bleeders push fluid in the same direction as the brake pedal, they won't put undue stress on your seals or brake lines. Once you have it set up, it's very easy to do a full system flush of your car's brake or clutch system.

The downside is that the adapters are model-specific, so if you plan to service a large number of cars, you need to have a few adapters on hand. Motive makes universal adapters, like this 3" metal adapter pictured here, but they can be fiddly because they are designed to be attached to the master cylinder with hooks and chains. Pro tip: Skip the chains and use pair of ratchet clamps to hold the adapter to the brake reservoir.

Pros:

  • Sure fire way to bleed all of the air and old fluid out of your car's brake or clutch system
  • Continuously supplies fresh fluid to the system as you bleed
  • Won't cause undue stress on rubber lines and master cylinder seals

Cons:

  • Some adapters can be fiddly (e.g. all of the ones that aren't the screw-on type)
  • Not very portable
  • Expensive, especially if you buy adapters for different cars

 

Conclusion and Recommendations

So which of these one-man brake bleeding tools is best? For the home mechanic or the track-day enthusiast, I recommend either the Inline Check Valve or Speed Bleeders. They are durable, cost effective, and are easy to use whether you are working at home or bleeding your brakes between track sessions.

If you plan to work on a large number of cars or are planning to do major brake system work on your car, I recommend investing in a Push Type Power Bleeder. Yes, it's the most expensive tool but it's well worth it when you consider the amount of time and frustration it saves you during big jobs.

 

Stay safe and keep those brakes in good shape. See you at the track.

~R

 

Disclosure Section:

StudioVRM is not sponsored or supported by any brake companies. All of the items here were paid for out of Roger's own pocket except the Motive Power Bleeder, which a friend and former roommate left behind when he moved out. I bought the universal adapter though so it wasn't really free either.