Power Steering Not Working? Why the Wheel Went Heavy and What to Check
You go to park and the wheel suddenly feels like it belongs on a truck from the 1970s. Or it creeps up over a few weeks until low-speed manoeuvres are a proper workout. Either way the power steering has stopped doing its job, and the car has effectively reverted to manual steering, which is heaviest exactly when you need it most, at parking speed.
The good news is the car is still steerable, it is just hard work. The important news is that the fix splits down one fork right at the start: is your car hydraulic or electric power steering? Chase the wrong one and you will waste time and money, because they fail for completely different reasons. So sort that first.
Hydraulic or electric? Work this out before anything else
Hydraulic power steering is the older, still very common setup. A pump driven by the engine belt pressurises fluid to help turn the wheels. If your car has a power steering fluid reservoir under the bonnet and a belt-driven pump, it is hydraulic. This covers most cars up to the mid 2010s and plenty since.
Electric power steering, often badged EPS or EPAS, uses an electric motor instead of a pump and fluid. No reservoir, no belt for the steering, and usually a dedicated steering warning light on the dash. Most newer cars use it because it is lighter and more efficient.
Knowing which one you have tells you which half of this guide applies. If you are not sure, check for a power steering fluid reservoir. If there is one, you are hydraulic. If there is not, and you have a steering warning light, you are electric.
If it is hydraulic power steering
Low fluid, usually from a leak
This is the most common cause by a mile. The system runs on fluid, and if the level drops the assist fades, often with a whining or groaning noise as the pump draws air, especially on full lock. Check the reservoir level. If it is low, you have a leak somewhere, commonly at the hoses, the rack seals, or the pump itself. Topping it up will help temporarily, but the leak needs finding. If the main symptom is noise rather than lost assist, our guide on noises when turning covers that side.
A worn or failed pump
Pumps wear out. They often warn you first with a whine that builds over weeks, then start losing assist, particularly when cold or at idle. If the fluid is full and clean but the pump is noisy and weak, the pump is the suspect.
A broken or slipping drive belt
Here is the one that fails suddenly and completely. The same belt that drives the steering pump usually drives the alternator and often the water pump too. If it snaps or is slipping badly, you lose steering assist instantly, and you will very likely also get a battery light and a climbing temperature gauge at the same time. If your steering went heavy and the dash lit up together, suspect the belt and treat it as urgent, because the overheating side is the bigger risk. We cover that combination in battery light on while driving.
The tricky "fluid is full, no noise, no assist" case
Sometimes the fluid is topped up, there is no whine, and there is still no help at the wheel. That usually points at the belt having come off, a pump that has failed internally without noise, or a seized pump pulley. It is also the point where it is worth confirming you actually have hydraulic steering and not an electric or electro-hydraulic setup, because chasing fluid on an electric system gets you nowhere.
If it is electric power steering
A stored fault and the EPS warning light
Electric systems are managed by a control module, and when that module detects a fault it will often disable the assist and drop you to manual steering as a safe default, with the EPS or steering light on. The cause can be the torque sensor that reads your input, the motor itself, wiring, or the module. Because it is electronic, a transient glitch sometimes clears with a restart, so turning the car off and on again is a legitimate first try. If the light comes straight back, it needs a scan to read the stored code.
Low voltage or a charging fault
This one surprises people. Electric power steering pulls a lot of current, so if the battery is weak or the charging system is failing, the car can shed the steering assist to protect itself, and the steering goes heavy. If your EPS dropped out and you also have a battery warning light or other electrical gremlins, sort the charging system first, because the steering may just be a symptom. Again, battery light on while driving is the place to start there.
A blown fuse
Simpler than it sounds and worth a look. A blown steering-circuit fuse will disable the assist outright. Check the relevant fuse before assuming the worst, it is a cheap thing to rule out.
Sudden versus gradual tells you a lot
- Sudden, total loss points at a belt (hydraulic) or an electrical fault or fuse (electric). Something switched off rather than wore out.
- Gradual heaviness over weeks, often with noise, points at a fluid leak or a wearing pump on a hydraulic system.
That single distinction narrows the field before you have opened the bonnet.
Is it safe to drive?
The car remains steerable with the assist gone, so you are not going to lose control, but it is much heavier at low speed and takes real effort to park or do tight manoeuvres. Drive it gently to somewhere you can sort it rather than committing to a long trip, and be extra careful in car parks and tight turns where you need the most input. The one case to treat as stop-now is the snapped-belt scenario on a hydraulic car, because the same failure is cooking your engine, not just weighting your steering.
How to diagnose it yourself
- Identify the system. Fluid reservoir and belt-driven pump means hydraulic. No reservoir and a steering warning light means electric.
- Hydraulic: check the fluid level, look for leaks, inspect the belt, and listen for a whine on full lock.
- Electric: look for the EPS or steering warning light, try an engine restart for a transient fault, check the battery and charging system, and check the steering fuse.
- Check for company. A battery light or high temperature alongside the heavy steering points hard at the drive belt on a hydraulic car.
- Note sudden versus gradual. It sorts belt or electrical fault from fluid or pump wear.
What it costs to sort
In tiers rather than fixed numbers. A fluid top-up or a fuse is the cheap, do-it-yourself end, though a leak still needs finding. A drive belt is a cheap part and moderate labour. A power steering pump, a rack, or a leaking hose sits in the middle. An electric power steering module or torque sensor is at the higher end. Working out the system and the sudden-versus-gradual pattern first means you walk in knowing roughly which tier the quote should land in.
Frequently asked questions
Why is my steering only heavy when parking or at low speed? Because that is when the assist does the most work. At higher speeds the steering is naturally lighter and needs far less help, so a failing system shows up worst at parking speed and can feel almost normal on the open road.
My power steering fluid is full but the steering is still heavy. Why? On a hydraulic car that points away from a leak and toward the belt, the pump failing internally, or a seized pulley. It is also worth double-checking you do not actually have an electric system, where fluid is irrelevant.
Can a flat or weak battery cause heavy steering? On an electric power steering car, yes. The system needs solid voltage, and a weak battery or a charging fault can make it cut the assist. Fix the electrical side and the steering often comes back.
Will turning the car off and on fix it? On an electric system it sometimes will, if the fault was a transient glitch. If the warning light comes straight back on, the fault is stored and needs a proper scan rather than another restart.
Work out which one it is for your car
Heavy steering is a fork-in-the-road fault: hydraulic and electric systems look identical from the driver's seat but fail for completely different reasons, and the fix ranges from a fuse to a full rack. If you want to sort out which path you are on without guessing, that is what the TorqueBot AI car chat is for. Tell it your make, model and year, whether it came on suddenly or crept up, and whether any warning lights came on with it, and it will tell you whether you are looking at a hydraulic or electric system and work through the likely causes for your car.