Rick's Free Auto Repair Advice

How to bleed air from power steering

Bleed air from power steering

Any time you replace a power steering component you’ll get air in the system. Air in a power steering system creates a whining noise. In addition to the whining noise, you may see foam in the power steering reservoir

Turning the power steering lock to lock doesn’t always work

The old method for bleeding power steering was to start the engine and turn the steering wheel full left and then full right, called lock to lock. The problem with that method is that when power steering reaches the end of its travel, pressures can soar to over 2,000-psi. and that can blow out small seals if you keep the wheel in that position for too long or try it too many times.

Plus, the lock to lock method doesn’t always work with late model vehicles because they can trap air in the system.

Using a vacuum pump to bleed power steering is the best method

Just about every car maker now recommends using a vacuum pump to pull a vacuum on the entire power steering system. That pulls air bubbles to the top of the reservoir no matter where they are in the system. This procedure is just like the latest recommended procedures for bleeding a cooling system. Don’t want to buy a vacuum pump? Try renting a hand vacuum pump and adapter from the auto parts store. Or, just take your vehicle to the shop and pay them to bleed the power steering for you. It’s a 15-min procedure. Or, become an automotive engineer and design the system differently when you grow up.

Here’s what you need to bleed power steering

First, you need a vacuum pump.

bleed power steering, bleed brakes, bleed air out of cooling system

Mityvac vacuum pump with all the attachments you’ll ever need to bleed power steering, brakes, and you cooling system.

Next you’ll need a reservoir cover or adapter. Some companies make exact fit covers, but the universal covers in the vacuum kits usually work just fine. Or, pick up a Mityvac MVA660 Power Steering Adapter.

Mityvac MVA660 Power Steering Adapter to bleed power steering

Mityvac MVA660 Power Steering Adapter


With the engine off, place the cover or adapter over the reservoir and pump the vacuum handle until you see about 20” vacuum on the gauge. Keep the vacuum in place for about 5-mins. The vacuum should only go down by a few inches. If the vacuum goes down more than that, that’s an indication the tool isn’t seated properly or you have a leak somewhere in the system that’s allowing air in.

Then remove the cover and examine the fluid. You’ll probably see foamy bubbles. Wait for the bubbles to recede and then pull a second vacuum. Then start the car and turn the wheel left and right, but not lock to lock. If the whining and juddering is gone, call it a day. If not, repeat the procedure.

Use the vacuum tool to bleed the cooling system and bleed brakes

You can use the same tool to bleed your cooling system and bleed your brakes.

©, 2015 Rick Muscoplat








Posted on by Rick Muscoplat

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