Steering box Seal Leak Signs
A Steering Box relies on a number of internal seals to keep the hydraulic fluid within the box. The following are the common signs of seal failure on a Steering Box.
In short
Fresh fluid spots under the front of your car, dampness or oiliness of the outer casing, stiff low-speed steering, cracked or swollen seals, dark, foamy or gritty fluid in the reservoir: these are the main signs of a leaking steering box seal. The consequences for pump and rack can be expensive if you fail to diagnose the problem while it is still relatively minor.
Fluid Patches on the Ground
Fresh Power Steering Fluid Patches on the Ground: There will be a patch or ring of fluid on the ground near the front of your car. This can be a fresh spot every night and disappear in the day as you drive. Power Steering Fluid is very thin and spreads quickly.
Damp or Oily Casing
Healthy steering boxes are dry to the touch. Even slow leaking of power steering fluid can leave greasy marks or damp patches on the casing surface. We have found such marks around the input shaft, sector shaft and fill cap.
Stiff or Inconsistent Steering
A leak can let the fluid drop to a low level, which can cause the steering to feel stiff at low speed. The stiffness can be worse in some turns than others and is usually worse at low speed where the power steering pump is working hardest.
Visible Seal Damage
On some cars you can see the seals on the steering box where the shafts are exposed. Check for any signs of damage, such as cracks, swelling or hardening of the rubber.
Fluid Colour Changes
Check the reservoir fluid to check for any contamination by seal material. Dark brown or foamy fluid with a gritty texture is typical of a failing steering box seal. As degraded seal material is pumped around the system, it can wear other components to cause further damage. Early detection of a leak is therefore crucial to avoid expensive repair work to other components of the power steering system, such as the pump and rack.
Catching a seal leak early is a lot cheaper than the damage that can be done to the steering pump and rack when the fluid level drops too low. For more on keeping your car safe, see our guide to essential car safety in the winter.
FAQs
Is it safe to drive with a leaking steering box?
A slow weep may not stop you driving straight away, but keep a close eye on the fluid level and get it checked soon. If the steering becomes heavy or the level drops quickly, stop driving and have the car looked at, as you could lose power assistance.
Can the seals be replaced without replacing the whole steering box?
Often, yes. Many boxes can be resealed with a seal kit. If the shafts or housing are worn where the seals sit, a reconditioned box is usually the better long-term fix.
Which power steering fluid should I use to top up?
Use the type listed in your vehicle handbook. Some systems use automatic transmission fluid and others need a specific power steering fluid, and the wrong one can damage the seals.
Do stop-leak additives work?
They may slow a minor leak by softening and swelling the seals, but they are a short-term measure rather than a repair. A worn or damaged seal will still need replacing.