Power steering reservoir has small foam like bubbles when engine is turned on

1. Do NOT start the engine until the system is fully bled, doing so may cause damage to the power steering components. Pump internals are metal to metal so any air in the system can cause metal to metal contact and resulting damage.
2. Raise the front wheels off the ground
3. Turn the steering wheel fully to the RIGHT
4. Fill the reservoir to the "full cold" level & leave the cap off. Use only XADO CHF or Honda PSF-S fluid. Do NOT use automatic transmission fluid as transmission fluid does not contain the same friction inhibitors/additives and tends to breakdown and overheat. The use of transmission fluid will VOID the warranty
5. With an assistant checking the fluid level, turn the steering wheel slowly and smoothly lock to lock until the level drops in the reservoir. If the fluid level does not drop no fluid has moved through the system, this indicates an air bubble in the reservoir or pump. Until this bubble passes no fluid will circulate through the system. ? On systems with coolers you may need to cycle in excess of 40 times ? Do NOT turn the steering wheel fast as this will cause the fluid to overflow the reservoir, trapped air may cause the fluid to overflow. Thoroughly clean any spilled fluid so you can check later for any leaks
6. Check the fluid constantly to ensure proper level and that no bubbles exist. ? If you see any signs of bubbles recheck all hose connections then repeat the steps above. ? The fluid level should be steady
7. Disable the engine from starting ? Crank the engine several revolutions, if the fluid level drops there is compressed air trapped in the system, repeat the above steps until the fluid level remains stable. ? If the fluid foams while cranking wait at least 10 minutes or more until dispersed air has time to accumulate and purge through the reservoir.
8. Continue to repeat the steps above until the fluid level remains constant and no air bubbles are visible.
9. Now start the engine and check that the fluid remains at level and stable
10. Reinstall the reservoir cap
11. Return wheels to centre and lower wheels to the ground
12. Run the engine for two minutes and turn steering wheel in both directions
13. Do NOT hold the steering wheel against the stops
14. Verify the following conditions ? The steering is smooth ? Noiseless operation ? Proper fluid level ? No leaks ? Proper fluid condition ? No bubbles, foaming or fluid discolouration
15. If all of the above conditions are satisfied the bleeding procedure is complete
16. If any problem exists then turn off the engine and see special conditions below Special Conditions If you experience any of the conditions listed below then there is still air in the system. ? Foam or bubbles in the fluid ? Power steering fluid should not rise in the reservoir when the engine is turned off, if this occurs there is air trapped in the system ? Be aware of any periodic bubbles that could indicate a loose connection, leaky o-ring or a bad flare seat in either the pressure or return hose ? Discoloured fluid (milky, opaque or light tan colour) If you have any questions regarding this procedure please contact us before you install the replacement power steering pump that you have purchased from us, we will be happy to help you.

Power steering pump

Grinding or whining? A lot of power steering pumps kinda whine when turning. How long has it been since you've changed the power steering fluid? Since 2000??? It looses it viscosity kinda like motor oil. I'd change it first, that's the cheapest and easiest thing to do

Locating the Power Steering reservoir and adding PS fluid. 1999 Pontiac GP

The reservoir is clearly visible in the engine bay on the 3.1 litre engine cars.

For the 3.8 Ltr engine cars, use a flashlight to look down past the alternator for a black cap with a steering wheel printed on it to indicate the power steering fluid reservoir. ( passenger side of the vehicle).

Remove the cap of the power steering reservoir, clean the dipstick, re-insert and remove again to check the fluid level. If the level is at or below the low level mark, add fluid slowly, taking care not to fill above the MAXIMUM mark. It's best to add small amounts and re-check the level as you go to ensure you do not overfill the reservoir above the MAX level.

ONLY use the power steering fluid recommended for that vehicle by GM.

YOU HAVE A RUPTURE PRESSURE LINE IF YOU HAVE NO POWER STEERING FLUID IN THE POWER STEERING RESERVOIR.LOCATE LEAK THEN BLEED POWER STEERING SYSTEM BY ADDING POWER STEERING TO RESERVOIR.DONT OVER FILL BY FULL COLD MARK ON POWER STEERING DIP STICK.ADD FLUID TO RESERVOIR WAIT A 2 MINUTES.CHECK FLUID LEVEL AGAIN.WHEN POWER STEERING FLUID LEVEL STOP DROPPING.START ENGINE LET IT RUN FOR 10 SECONDS.THEN TURN OFF ENGINE CHECK POWER STEERING FLUID ADD FLUID IF FLUID LEVEL DROPS. WHEN FLUID LEVEL STOP DROPPING.SAFELY RAISE SUPPORT VECHICLE FRONT WHEELS.START ENGINE.NOW TURN STEERING WHEEL GENTLY FROM STOP TO STOP MEANING LEFT TO RIGHT DONT HOLD IN POSITION.LET THE STOP TO STOP BE QUICK.CHECK POWER STEERING FLUID AFTER YOU HAVE TURN STEERING WHEEL ABOUT 7 STOP TO STOP.WHEN FLUID LEVEL STOP DROPPING YOU AT HOT MARK ON DIP STICK BLEEDING PROCESS COMPLETE.TURN OFF ENGINE LOWER VECHICLE BACK TO GROUND WAIT ABOUT 5 MINUTES CHECK YOUR FLUID LEVEL.IF FLUID LOOKS LIKE A TAN COLOR.YOUR POWER STEERING SYSTEM FULL OF AIR.TURN OFF VECHICLE LET VECHICLE SET A LONG WHILE TO AIR BUBBLES SETTLE DOWN LOOK FOR LEAKS AROUND POWER STEERING PUMP FRONT SEAL AND CHECK FOR LEAKS AROUND POWER STEERING LINES.

When u fill; up the reservoir means u have a fluid leak!
Did u check where could be the leakage coming from?

the rack and pinion unit may have a pinhole leak

did you overfill the fluid resovior? the cap is vented and provides no seal, so it the tank is overfilled it will bubble out the cap, if the tank is not overfilled you have a defective steering rack that is pulling in air through a defective seal and causing the fluid to foam and bubble out the cap vent.

Hello hummelsautob.
Changing the power steering cooler can't allow air into the brake system. Two different fluid systems.
Your F250 has it's brake assist powered by the power steering pump.
Instead of using a vacuum assist it uses the hydraulic power from the pump.
When refilling your pump you have gotten air mixed in with the fluid. This turns it into a consistency something like whipped cream.
When in this state it isn't effective. Let it sit for a couple hours and let the air bubble out of the fluid. Recheck your level after this as it will drop.
This will make your brakes feel normal again.
Just a note on adding fluid to an empty power steering pump.
Add fluid to the reservoir but not to the top, turn the steering wheel back and forth slowly with the engine off. This will keep the fluid from foaming.

raise the truck up and turn the wheels left to right, you most likely have air in the lines.