I have a 2004 trailblazer my steering wheel pulses and my fluid level was low but no evedence of a leak

Air in the power steering pressure line. Is the power steering reservoir full? Check for leaks or breaks in the pressure line to ensure air is not getting into the system.

This is usually an indication of air in your power steering fluid. Check your power steering reservoir. If it is low service it to the recommended level. It may take some time for all the air to work out of your system, so don't expect the humming to stop immediately.

check power steering fluid level or for air bubbles in fluid, if low or bubbles found find and correct fluid leak. if fluid is ok most likely the pump is failing. Other possible causes are steering gear or linkage binding but are not very common problems.

Check the level of power steering fluid in the resovoir.
If low refill and your steering should come back.
Check for leaks by looking under the car and have someone turn wheel from one extreme to the other. Alot of times the fluid only leaks under high pressure when the wheel is turned

Check the power steering fluid level.
If the fluid level is low, you obviously have a leak somewhere and it should be repaired. If the level is up, watch the power steering pump while the engine is running; is the pulley turning freely?
Power steering systems are hydraulic devices. The pump provides the pressure and the steering gear or rack and pinion assembly (depending on the vehicle type) applies pressure in the direction that you are turning the wheel to assist with the steering. When the hydraulics fail or when the internal components fail, your strength is the only thing turning the steering.
But start with the fluid.

refill it, make sure you follow the level of fluid, it has two level hot and cold.... check for leaks also. there might be some leak causing to low level of steering fluids.

Check the power steering pump fluid level, if it is good, you may have a problem with the rack or a defective pressure hose.

that sounds like you are low on power steering fluid ... when the level gets low then the pump starts to ingest air and that produces a buzzing sound when you turn the wheel .....i would add or change the fluid and check for leaks and mechanical loosness in the under car linkages ...you can have that checked at your next oil change .

If it is making a noise in the belt area, have them check the water pump. These get loose water pump bearings that cause belt noise.

Check the power steering fluid level. What you describe could be the noise made when fluid level is low. It's not good for the pump, so if that's the problem, fill to proper level, check for leaks, as it shouldn't be losing fluid. countrycurt0