My power steering pump on my '79 Bronco has been leaking substantially lately. I changed the pump, started it up, no leaks, turned it off and a minute later it was squirting bad out the vent hole in the cap. It looked like "Old Faithful" shooting under my hood.

The new fluid also looks like it's been through a blender. Lots of bubbles and turned from clear to a foamy tan.

Anybody got any ideas as to the problem?

Quoted: My power steering pump on my '79 Bronco has been leaking substantially lately. I changed the pump, started it up, no leaks, turned it off and a minute later it was squirting bad out the vent hole in the cap. It looked like "Old Faithful" shooting under my hood. The new fluid also looks like it's been through a blender. Lots of bubbles and turned from clear to a foamy tan. Anybody got any ideas as to the problem?

Typical when installing a ford pump . You can either let it purge itself through running .
or you can rig up a cap for the pump with a nipple in it and pull vacuum on the system
to speed up the air puge from the fluid . They even make a stepped rubber stopper
just for this task that will work on other fluid system reservoirs that need to be purged as well as P/S systems .

Head over to the Cars and Bikes forum buddy, Im gonna do a Post on my 78 Bronco tommorw and would love to have some pics of your posted up there..

Jack it up and put the front axle on jack stands.

Fill reservoir.  Start truck.  Steer back and forth.  Top off and repeat until bubbles are gone.

Otherwise known as "purging" your power steering system.

Heh, while we've got the gurus here...

My 98 dodge 4x4 is doing the same thing but to a lesser extent.  It's got a slow leak and my local shop says it needs to be replaced at the tune of $400.  I can get another new one for under a hundred (after core).  Should I just replace it myself?  It's a pretty slow leak...Makes funny noises when I turn too.

Quoted: Heh, while we've got the gurus here... My 98 dodge 4x4 is doing the same thing but to a lesser extent.  It's got a slow leak and my local shop says it needs to be replaced at the tune of $400.  I can get another new one for under a hundred (after core).  Should I just replace it myself?  It's a pretty slow leak...Makes funny noises when I turn too.

If you have to ask, you probably shouldn't, however, it is not difficult to replace your power steering pump and hoses and you can do it yourself AND buy the tools to do it for less than half that.

The instructions that came witht he new pump say the pump will purge itself. It doesn't say how long this will take. I'll give cycling the steering back and forth a try.

Ford wanted over $300 to change my pump. $180 for a pump I got from Advance Auto for $40, and 2 hour, $140 labor charge. WTF? I changed it myself in less than 30 minutes.

Advance Auto also has a loaner tool program. You basically buy the pulley puller but if you bring it back within 45 days, you get all your money back.

The purge these guys are discussing is kind of like bench priming a brake master cylinder:  When you replace it, you've introduced a new part that has sealed cavities that hold air, and that air has to be removed.  Like bleeding your brake lines after you change the pads (unless you know the shortcut).  It's dangerous with brakes, of course, but just messy on a power steering pump.  

Raising the front end and turning the wheel is really the easiest method to purging.

I'm also stupid. These old Fords use "F" type tranny fluid for the power steering pump. Some of my problems are due to using the wrong fluid. I did fill it up with tranny fluid today and purged it for 15-20 minutes. I still have bubbles but the fluid did not shoot out of the vent hole when I shut the engine off.

Maybe another 15-20 minutes of purging will fix it.

Quoted: I'm also stupid. These old Fords use "F" type tranny fluid for the power steering pump. Some of my problems are due to using the wrong fluid. I did fill it up with tranny fluid today and purged it for 15-20 minutes. I still have bubbles but the fluid did not shoot out of the vent hole when I shut the engine off. Maybe another 15-20 minutes of purging will fix it.

If type F doesn't work for you, I *believe* synthetic Dextron/Mercon ATF is an acceptable substitute, and may have better anti-foam agents, being a newer concoction.  

As I recall (someone correct me if I'm wrong) type F trans fluid merely had different friction properties (no friction modifiers added) than the Dextron/Mercon family, and never made all that good of a hydraulic fluid.  Dextron in a Type-F trans could very well make it slip, but all I can see it doing in a PS system is gaining you the advantage of a more slippery oil (which presumably would reduce wear).

One of the vehicles I own is known to have PS pump problems (3 of them were put on before I bought it).  I replaced the PS fluid with synthetic ATF and it has been fine since.

I tend to believe none of that shit makes much of a difference - I have trucks where the transfer case takes auto trans fluid, the other transfer case takes motor oil - neither of them take gear oil!  I have run into manual transmissions that take AT fluid too.  Weird.  I can't imagine why a manual trans would take a modified hydraulic fluid - if gear oil is too viscous, why not motor oil?  

Same with PS systems - some of them specify "power steering" fluid and some require AT fluid.  Goat urine mixed with boiled linseed oil with a touch of anal-ease might work fine too for all I know.

You can always go to the source - BITOG forums.

Do we have any tribologists on the board?

Kinda like lubing an AR with tranny fluid. Sometimes the lubricant doesn't really matter.