Pressure or Vacuum Brake Bleeder? How to Bleed Brakes on Your Own

No one to pump the pedal? A one-way valve bottle, a vacuum bleeder or a pressure bleeder lets you bleed brakes alone. Here is how to pick one, stop air creeping in, get a cap that seals and handle ABS.

The Brake Bleeding range at PartsForMachines has 94 products, including more than 50 bleeders, reservoir caps, bleed screws and spanners from Sealey, Sykes Pickavant, Draper and PCL.

Pressure or Vacuum Bleeder: Which Is Easier When You Work Alone?

It depends on your car and air supply: a vacuum bleeder needs no reservoir cap, while a pressure bleeder needs a cap that seals but tops up the reservoir for you. Simplest of all is a one-way valve bottle such as the VS0212 bleed bottle: with its hose on the nipple, open the nipple slightly, press the pedal slowly, close it again and release the pedal. Repeat until the clear hose shows no air.

Air-powered vacuum bleeders run on workshop air: the VS020 vacuum bleeder, for example, needs 90–120psi and uses 180 litres a minute. A pressure bleeder pushes fresh fluid in from the top, and a big bottle can flush the whole system in one fill.

Why Does My Vacuum Bleeder Keep Pulling Air Bubbles?

Either air is still coming out of the system or more is getting in. Keep the reservoir topped up, because if it runs dry, air gets back into the system. At the bleed nipple, push the hose firmly on and open the nipple only slightly.

Sealey says the neoprene seals on its VS4511 8 and 9mm bleeder spanner stop air getting into the system at the nipple. Close the nipple once the fluid in the clear hose runs bubble-free.

Will the Bleeder Cap Seal on My Brake Reservoir?

Only if it matches the reservoir neck, so check the old cap: diameter, screw or twist-on fitting, and seal. Many pressure bleeders come with a 45mm cap that suits most European models. The VS0205 tyre-powered bleeder has four caps: 25mm for Lockheed, 27mm for VAG, 46mm for some Girling systems, and 44/45mm for metal Girling and ATE, with a thin seal for 44mm necks and a thick one for 45mm.

Other cars need a bayonet cap or a universal rubber cone; the VS0204B set has both. If a cap leaks under pressure, release the pressure, check the seal and refit the cap, then keep the pressure low.

Does a Car With ABS Need a Special Bleeding Kit?

Not usually a special bleeder: low-pressure bleeders are sold as ABS compatible, such as the VS1205 with its valve set at 20psi (1.4 bar) and the VS820, which works at up to 28psi. The catch is the ABS unit itself: some systems need its pump and valves cycled during the bleed, especially if air has got in, for example after the reservoir has run dry. On some cars that takes a diagnostic tool.

Check the bleeding procedure in that model’s workshop manual before you start. If it calls for a tool you lack, a garage with the right equipment can finish the job.

What Should I Check Before I Buy?

• how you will power it: a hand pump, tyre air or a workshop compressor big enough for an air-powered bleeder
• the reservoir cap: neck diameter, screw or bayonet fitting, and seal
• the bottle size: enough to flush the whole system in one fill
• the bleed pressure and procedure in your workshop manual, especially with ABS
• nipple and screw sizes: spanners in 8/9mm and 10/11mm, bleed screws in M6 to M10 and 1/4 or 3/8 UNF

Browse the Brake Bleeding range, or contact the PartsForMachines team by WhatsApp, telephone or email with the vehicle make, model and year. A photo of the reservoir cap helps.

Product options, delivery options and returns terms are shown on each product page. A 30-day return policy applies to eligible items.

Frequently Asked Questions

What pressure should I set on a pressure bleeder?

Keep it low, and use the vehicle maker’s figure if the workshop manual gives one. The tyre-powered VS0205 limits pressure to 20psi, and caps such as the VS0204C4 are rated for 1–2 bar (14–30psi).

Do I need to keep topping up the reservoir while I bleed?

With a one-way valve bottle or a vacuum bleeder, yes: a dry reservoir lets air back into the brakes. A pressure bleeder feeds the reservoir for you as long as its own bottle holds enough fluid.

How do I refill a pressure bleeder mid-job without fluid spraying out?

Release the pressure before you open the bottle or lift the cap, as both are under pressure while connected. The VS821 has an air pressure release valve. Better still, use one big enough for the whole job, such as the 3-litre VS0215.

Which pressure bleeder works without a compressor or a spare tyre?

A hand-pump type: fill it with fluid and pump it up. The VS1205 one-person bleeder holds 400ml and has a control valve set at 20psi, while the VS820 pump-up unit holds 2.5 litres for bigger systems.

Is a one-person kit as good as a helper on the pedal?

It can be. Whichever method you use, keep going at each wheel until the fluid runs clear with no bubbles. A kit simply lets you do the job alone, and a pressure bleeder also helps stop the reservoir running dry.

Where does the old fluid go with a vacuum bleeder?

Into the bleeder’s own tank, so check its size before a full fluid change. The VS020 holds 1 litre, and the 2-litre VS0203 stops drawing automatically when its tank is full.

Which brake fluid can go in a pressure bleeder?

Check the bleeder’s fluid list against the fluid your vehicle uses. The VS0204, for example, takes DOT 3, 4, 4LV and 5.1 glycol-based fluids, but not DOT 5 silicone fluid.

My bleed screw is rounded or seized: which replacement do I need?

Match the thread, pitch and length of the old screw. Replacements come in M6, M7, M8 and M10 metric and 1/4 or 3/8 UNF sizes, and the AB160BN box holds 160 screws in eight common sizes.

Can I bleed the clutch with the same kit?

Often, yes: many bleeders in the range are sold for brakes and clutches, including the VS020 and VS0205. Check the cap fits the clutch reservoir and follow the vehicle maker’s clutch bleeding procedure.