Power steering pump: failure symptoms, noise and causes

TSS power steering pumps for the Jetta A4, Aveo and NP300

In short

The power steering pump is driven by the engine belt and sends fluid under pressure to the rack; cars with electric power steering (EPS) don't have one.
Typical symptoms are heavy steering, especially when parking, a whine or squeal when turning, foam in the reservoir and leaks.
Many pumps are replaced without being faulty: check the fluid level, the belt and air in the system first. GM found many returned pumps with no fault.
What damages them most is running low on fluid or with air, holding the wheel at full lock, and contaminated or wrong fluid.
Before fitting a new pump, find the cause, flush the system, check the hoses and bleed out the air: if there are metal particles, the rack is replaced too.

The power steering pump is what makes the wheel turn lightly. When it fails, the steering gets heavy, whines when you turn or leaks fluid, and many people replace it first. But it isn't always the pump: here's how to tell if it's failing, what to check first, why it fails, how to bleed the system and which TSS pump your car takes, according to service manuals, carmaker bulletins and pump makers' instructions.

What does the power steering pump do and where is it?

It sits at the front of the engine and is driven by the accessory belt, on some cars the same one that drives the alternator. It draws fluid from the reservoir and sends it under pressure, through the high-pressure hose, to the rack (or to the steering box on large trucks); the fluid returns to the reservoir through the return hose. For reference, Nissan's service manual for the Altima gives a maximum pump pressure of 82 to 90 kg/cm² (1,160 to 1,276 psi). More on how the system works in what the power steering pump does, from veinte07 (in Spanish).

Some pumps have the reservoir built in and others are "without reservoir" and use a separate one; some are sold with the pulley and others without it, in which case you move the old pump's pulley over. Cars with electric power steering (EPS) have no pump: among others, the Aveo from 2024, the Silverado from 2014, the Accord from 2013 and the Trax 1.4 turbo. If you don't know which your car has, we cover it in power steering rack and pump: which one your car takes.

How do you tell if the power steering pump is failing?

The steering is heavy both ways, especially when parking or at low speed.
It whines, squeals or clicks when you turn the wheel.
The fluid in the reservoir has bubbles or foam.
There's fluid on the pump, its hoses or under the front of the engine.
Assist comes and goes: it gets heavy for a while, then light again.

Careful: those symptoms aren't always the pump. A US GM bulletin says that analysis of pumps returned for noise, no assist, low pressure or leaks found "a high number of no trouble found results". Before replacing it, check the fluid level, the belt and that there's no air in the system.

Symptoms and what to check first

Symptom	Likely cause and what to check
Heavy steering both ways	Low level, air, a loose or slipping belt, or a pump that no longer makes pressure. Check tire pressure too.
Heavy one way only	It's rarely the pump: per Borg Automotive, it's usually debris in the system, a collapsed hose or the rack. Check the suspension too.
Whine when turning	Most likely air in the system, per Cardone; also low fluid or a worn pump. Bleed the system before replacing parts.
Squeal at startup or at full lock	A loose or worn belt slipping on the pulley. Check its tension and condition.
Bubbles or foam in the reservoir	Air in the system: it needs bleeding, the level is low or air gets in at a loose connection.
Fluid leak	The pump, its hoses or its O-rings; if the leak comes from the boots, it may be the rack.
Assist comes and goes	A slipping belt, low level or, on cars with electric steering, overheating protection (that's normal).

Heavy steering when turning: pump or rack?

If the steering is heavy both ways, start with the simple things: the fluid level, the belt and tire pressure. If it's heavy one way only, the rack or a hose is more likely. To be sure, the shop measures pressure: Nissan's service manual calls for a gauge with a shut-off valve; with the valve closed, if pressure rises to maximum the rack is damaged, and if it stays below, the pump. The valve must not stay closed for more than 15 seconds. More causes in what to do when the steering gets heavy, from veinte07 (in Spanish).

Cars with electric steering have no pump: if assist drops after moving the wheel a lot with the car standing still, that's overheating protection. Per Nissan and Toyota Mexico's manuals, assist comes back on its own after a while.

The power steering pump makes noise: whine, squeal or click

Whine: pump maker Cardone says the most likely cause is air in the system. Per Nissan's manual, if air is left after a repair there are bubbles in the reservoir and the pump clicks or buzzes excessively.
Some noise is normal: Nissan explains that fluid can be heard in the valve or pump with the car stationary or when turning the wheel slowly, without affecting how it works.
Squeal: it's usually the belt. Nissan checks belt tension before testing the pump and after installing one.
Noise that seems to be steering but isn't: the strut mounts, or the axles at full lock.

Why does a power steering pump fail?

Running with low fluid or with air: the pump is lubricated by the same fluid it pumps.
Holding the wheel at full lock: Nissan says not to for more than 10 to 15 seconds because the pump can be damaged, and GM no more than 5 seconds above 1,500 rpm because the fluid overheats and damages the pump, reservoir and hoses. The 2020 Trax manual in Mexico says more than 15 seconds can damage the system.
Contaminated fluid: debris or metal from a failing rack goes into the new pump.
The wrong fluid: each carmaker specifies its own. VW, for example, calls for hydraulic oil and says not to use ATF.
The belt and its bracket: in the US, Volkswagen recalled 1990 Jettas because the pump bracket could break and the belt slipped.

Before you replace the power steering pump

Pump makers agree: a new pump won't fix the rest of the system. ELSTOCK puts it this way: "Before installing a new steering pump, determine the cause of the old pump's failure." What they ask for:

Flush the system and check the old fluid: pour it through a paper filter. Per Maval, if there are metal particles, replace both the pump and the rack.
Don't reuse drained fluid, as Nissan's manual says.
Check the hoses: ELSTOCK explains they wear from the inside and that if any is stiff, porous or hardened, all should be replaced. Replace the O-rings at the connections too.
Clean the reservoir and its screen, if it has one.
Check that the new pump has the same pulley, mounting and connections as the old one.
Remove and fit the pulley with a puller, never with a hammer or a press, per Maval.
Move the pressure sensor over from the old pump, if it has one: per Maval, if it isn't transferred correctly, the shaft seal fails.
Adjust the belt tension at the end.

How to bleed power steering

Each carmaker has its own procedure, and it's best to follow the manual's. Nissan's, as an example:

Raise the front of the car until the tires are off the ground.
Fill the reservoir to the specified level with the fluid the carmaker calls for.
With the engine off, turn the wheel from lock to lock, without forcing it against the stops, until the level stops dropping. Don't let the reservoir run dry.
Start the engine and repeat.
Check the level against the right mark: the cold and hot marks are different.

If it still makes noise, Maval recommends letting the car sit for a while and repeating. Some cars need a vacuum pump to get all the air out.

Which power steering pump does your car take?

TSS power steering pumps and the cars they fit. Where we could, we confirmed the number with the carmaker's catalog; the rest is what TSS lists. Compare your pump's part number before ordering:

Vehicle	TSS pump
Volkswagen Jetta A4 and Golf A4 2.0 and 1.8 turbo, 1999 to about 2008, and Beetle	pump 1J0 422 154 H, no reservoir or pulley; it's the number in VW Mexico's catalog. The 2009 to 2015 Jetta Clásico lists a different pump: confirm it. Not for the Gol.
Volkswagen Jetta and Golf A2 1.8, 1987 to 1992	pump 027 145 157, no reservoir or pulley; the number matches VW Mexico's catalog.
Chevrolet Aveo 1.6, 2008 to 2017, and Pontiac G3	Aveo pump, no reservoir, with pulley. The Aveo from 2024 has electric steering and no pump.
Chevrolet Sonic, 2012 to 2018, and Trax, 2013 to 2020	pump 95040945, no reservoir, with pulley. Per the 2020 Trax manual in Mexico, the 1.8 is hydraulic and the 1.4 turbo electric.
Chevrolet Silverado 4.3, 4.8 and 5.3, 1999 to 2013	pump 26081016, with reservoir, no pulley. The Silverado and Cheyenne from 2014 have electric steering.
Chevrolet Equinox and Pontiac Torrent, 2005 to 2009	pump 20954812, TSS also lists it for the Captiva and Traverse: confirm your pump's number.
Nissan NP300 Frontier (D23) 2.5 gasoline, from 2016	pump 49110-4JM0A, QR25DE gasoline engine only; not for the diesel.
Nissan X-Trail 2.5, 2001 to 2007	pump 49100-8H305, no reservoir, with pulley.
Nissan Urvan 2.4, 2002 to 2006	pump 49100-VW000, with reservoir and pulley. Not for the Urvan 2.5.
Nissan Altima 3.5, 2007 to 2012	pump 49110-JA100, TSS also lists it for the Maxima and Murano: confirm the number.
Nissan Platina and Aprio; Renault Logan, Sandero, Stepway, Kangoo and Megane (per TSS)	Platina and Renault pump, no reservoir, with pulley.
Ford Ka, Fiesta 2003 to 2010 and EcoSport 2004 to 2012 (per TSS)	Ka, Fiesta and EcoSport pump, no reservoir, with pulley.
Ford Explorer and Mercury Mountaineer 4.0 through 2005, and Ranger 4.0 (per TSS)	pump F77Z-3A674-EBRM, no reservoir or pulley; 4.0 engine only.
Honda Accord 2.4, 2008 to 2012	Accord 2.4 pump, no reservoir, with pulley. From 2013 the Accord has electric steering.
Dodge Verna 1.5 and 1.6, 2004 to 2006	pump 57110-22502, with pulley; reuse the reservoir or buy it separately.
Fiat Palio 1.6 and 1.8, 2013 to 2020, Strada and Punto (per TSS)	long-shaft pump, long shaft: TSS warns it doesn't fit where the short-shaft pump is needed.
Mercedes-Benz Sprinter 2.2 and 2.7 (per TSS, 2008 to 2021)	Sprinter pump, with reservoir and pulley; confirm the year with your pump.

See TSS power steering pumps

TSS power steering pumps

TSS has new power steering pumps for the cars in the table, and racks for many more: see power steering rack and pump. If the leak is from the rack, veinte07 explains when to use a seal kit (in Spanish). In Mexico you can also see all the power steering pumps at Transmisiones Veinte 07, and in the US, Sun Transmissions sells pump seal kits.

TSS is an aftermarket brand with OEM-comparable quality and quality control on every product. It's sold through our authorized distributors: in Mexico, the full TSS catalog is at Transmisiones Veinte 07, and in the United States at Sun Transmissions.

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