FL 60 pukes steering fluid out of reservoir

[timruger1]

I have a new to me 98 FL 60. If I hit the brakes fluid is forced out through the power steering reservoir vent

When I shut off the truck fluid is again forced out past the reservoir vent. Do I start with the power steering pump or the hydraboost?

The

 

[r3gulator3]

Need to get all the air out of the system, raise the front wheels off the ground, engine off and power to the hydro booster disconnected. Full right turn, pump the brakes 3 times full left turn, pump brakes 3 times check fluid level. Do this 10 times. Hook power back to your hydro booster. Then road test and if you still have a problem we will go from there.

 

[timruger1]

I can do that but why would there randomly be air in the system?

I haven’t changed the pump or the hydro boost yet

 

[timruger1]

Also when you say disconnect power to the hydro boost do you mean electrical power or the high pressure line?

 

[r3gulator3]

Electrical power. Is there a leak in the system anywhere?

 

[r3gulator3]

Look inside the cab behind the brake pedal, any wetness there?

 

[timruger1]

No leaks or wetness in the cab

 

[r3gulator3]

My best dart at the wall is that you’re hydro booster is bad, they are a very common failure. Even if it looks like fluid had ran down the fire wall in the engine bay at some point that is your likely culprit. Sometimes it will leak between the booster and the master cylinder. And very little if any will come out but there is enough leak there to put air in the system.