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So I started hearing a whining noise like a low power steering fluid noise, sure enough, low power steering fluid.
Then I noticed the oily residue down on the Arm and then saw this connection had come loose.
1) I was told this is the “pressure” line for the automatic locking 4x4. Can someone confirm this?
2) Does it use power steering fluid for this system?
The front hubs use vacuum for locking which is provided by the engine vacuum pump that also provides vacuum to the brake booster on non-hydroboost Super Dutys. They are not hydraulic.
Darn it, thought I had solved the problem. I can’t see anywhere from above that it could be leaking from. Guess I’ll clean it all up and check daily until I track the source. The vacuum pump that you are referring to is the power steering pump though right? Does the pump use fluid to create pressure for the brake booster? Somehow PS fluid is back up under the “master cylinder”
The vacuum pump is a separate device from the power steering pump. It uses no oil. It just creates an air vacuum. It is the replacement for the manifold vacuum that a gas engine uses to operate a conventional brake booster . Nothing in the vacuum system, including the booster and the front hub locking system involve the use of oil.
Darn it, thought I had solved the problem. I can’t see anywhere from above that it could be leaking from. Guess I’ll clean it all up and check daily until I track the source. The vacuum pump that you are referring to is the power steering pump though right? Does the pump use fluid to create pressure for the brake booster? Somehow PS fluid is back up under the “master cylinder”
I have a leak in the same spot on my ‘19. No issues yet but I have it scheduled to go in next week for a service.
power steering pump fittings - does it have the correct level of fluid ? Wipe everything down, clean all areas, refile PS and see if its leking
Steering box
Brake fluid reservoir and booster
radiator over flow bottle
Could the last several oil changes have some spillage? A little oil can look massive over time
With my first response I missed the fact that your truck is an F350 (not F250). You most likely have a hydro-boost brake booster. This device uses pressure from the power steering pump to provide your brake boost. There are hoses going to and from the power steering pump to the hydro-boost unit that is between your brake master cylinder and the firewall. Check all those fittings for leaks. The supply line is under high pressure and is pretty substantial, but the return line is just a piece of regular hose.
With my first response I missed the fact that your truck is an F350 (not F250). You most likely have a hydro-boost brake booster. This device uses pressure from the power steering pump to provide your brake boost. There are hoses going to and from the power steering pump to the hydro-boost unit that is between your brake master cylinder and the firewall. Check all those fittings for leaks. The supply line is under high pressure and is pretty substantial, but the return line is just a piece of regular hose.
BINGO! Yes, that’s exactly what I am dealing with. I cleaned everything today with degreaser multiple times and letting it all dry overnight. I’ll keep checking daily until I see the leak source. My bet is the high pressure side at the booster (master cylinder).
So after replacing both my high pressure P/S hoses from the pump to the booster and from the booster to the gear, I still had a leak...discovered that it was actually an internal seal in the
hydrobooster and the "leak" was coming out of the weep hole in the bottom of the booster. Replaced the booster and now am cleaning and drying out, but the P/S level in the reservoir
are holding steady and I don't have anymore noticeable drips. Hopefully this fixed it, just didn't expect a failure at 52K and 2 years in.
I am surprised that the hydroboost failed that soon. They are normally bullet proof. My 2009 F250 6.4 was 12 years old when I sold it and no problems with the hydroboost. I have installed one in my 1968 Corvette and, unlike the truck, it is almost never driven and no failure in 10 years, so whether it is used or sits, it is normally reliable. You just must have gotten a defective one by the luck of the draw. Glad you figured it out. I can see how a drip from the weep hole being blown around the engine compartment would be a b..ch to find.
