What does power assisted steering (PAS) fluid do?
power assisted steering (PAS) fluid is the hydraulic liquid that is used in vehicles with a power assisted steering pump which is forced under pressure into the steering rack system to reduce the effort needed to turn the steering wheel.
How does power assisted steering (PAS) fluid work and what are the components?
Like all hydraulic fluid, it has a high resistance to compression and therefore it can be used to force the piston it is pushing without losing effort. When the PAS pump is running, the fluid is drawn in from the return pipe and then pressurised by the impeller back down the high pressure pipe. This effort is then used to assist the driver in turning the steering wheel.
How do you know there is something wrong with the power assisted steering (PAS) fluid?
There are some obvious signs to the driver that something is amiss with the fluid as follows
- The steering wheel is heavier to turn than normal.
- When there is a squeaking or grinding noise from the unit when turning the wheel.
In addition to this, the fluid can be checked physically by removing the fluid reservoir cap (it usually has a picture of a steering wheel on it). If the fluid is clear, or bright in colour (usually green or red) then it's likely to be OK, If it is brown to black, then it has likely been contaminated.
When should you consider a power assisted steering (PAS) fluid replacement?
Like all hydraulic fluid, power assisted steering fluid absorbs moisture over time and becomes less effective. Therefore replacement should be done every 5-7 years.
How common is a power assisted steering (PAS) fluid replaced?
As the fluid should be replaced at regular service intervals, it is a common task to be done.
How can I extend the life of my power assisted steering (PAS) fluid?
There is nothing you can do except check the level and ensure the cap is tight on the reservoir.
What happens during a power assisted steering (PAS) fluid replacement?
Changing power assisted steering (PAS) fluid is a routine repair for all mechanics and can be done both kerbside as well as in the workshop, providing it is safe to do so.
Whilst there are variations between manufacturers, the basics are pretty similar.
The mechanic will;
- Check the condition of the fluid and proceed if deemed to require changing
- Undo the system bleed valve and drain the existing fluid out
- Depending on how tainted the fluid was, either refill it and bleed it or flush it through before refilling it and bleeding it.
- Test the vehicle’s steering once again
How much does a power assisted steering (PAS) fluid replacement cost?
The cost of replacing power assisted steering (PAS) fluid depends on your car and what parts your car's manufacturer recommends using for the replacement. Find out what you could save by having your power assisted steering (PAS) fluid replaced by ClickMechanic, by selecting your car at the top of this page!