Big Blue's Power Steering Leak

[Gary Lewis]

The other day when Steve/FoxFord33 and I took Big Blue to Stillwater and back, a round trip of about 200 miles, I noticed some drops of oil on the pavement where we'd been.  I checked the power steering system and it was low, so today I started looking for the leak and I think I've found it - but want all of y'alls input.

The first thing I noticed was the driver's side frame is wet.  You can see that there's a drop of lube on the bolt head at the top of the picture on the left, but what you can't really tell is that the frame is wet in lube.

Second thing I noticed was that the driver's side inner fender is wet - on the front.  But there are no hoses of any kind on the top side.  In fact, there's no oil on the top side, so this oil had to come a different way.

The third thing I noticed was that the fittings to the new Blue Top steering box are peeking through the opening between the frame and the fender liner.  And if one of those was leaking it might spray the inner fender and that would run down on the frame.

So then I looked closely at the fittings and found that there was oil showing in the threads of the larger one, which you can see in the very last pic.  I was able to tighten both of them up - some.

So, do you think this could be the leak?  I've refilled with as much Royal Purple Synchromax as I have, but it is still low so I don't want to drive it until I get it filled up.  However, I don't see a leak now, so????    

(Don't get sidetracked on the Purple Max thing.  Since this system is for both power steering and hydroboost braking I was afraid that the lube would get hot, so did some research and this is what Royal Purple's tech recommended for the application.)

[Ford F834]

Gary, if you start the truck and have someone clock the steering full stop in both directions it might show itself if there is still a leak. I would also check the hydroboost return with someone applying the brake.

[Gary Lewis]

I'll check that, Jonathan.  Thanks.

But I should have said that I've checked all the other lines and they are dry.  Not a bit of lube anywhere except on the front of the frame and the fender liner.

[viven44]

Looks like the leak is around the threads (only?). Aren't those straight threads (flare fitting) ?

[Gary Lewis]

Yep, it is a flared fitting so the threads aren't what seals it.  The flare does.  But if flare leaks there will be oil around the threads.

I tightened it TIGHT and started it up.  There was no oil coming out.  But since the level in the pump is below the reach of the dipstick I didn't want to run it very long.

The quart I ordered won't be in until Wednesday, so in the interim I think I'll clean it up and take it for a spin to see if it makes the same mess.  Won't go very far, but far enough to get it good and warm.  And I'll do the tests Jonathan suggested.

[viven44]

I had a mechanical fuel pump on a 1980 where the fuel pump output flare fitting leaked and it would leak a lot of gas. It took a ridiculous amount of tightening to stop that leak, but here you are dealing with oil which is more viscous however with the PSIs involved in the PS pump -- I can totally see an imperfect flare seal being the cause. Hope that fixes it.

[Gary Lewis]

Those are the same lines that were working fine on the previous steering box.  So it isn't the flare.  Maybe it just wasn't tight enough?

[viven44]

Since the flare union involves 2 surfaces, those 2 surfaces do move with one another. Wild guess would be that they lines were "formed" while mating with the previous steering box's female flare-end. I don't know how tightly the angles are controlled in manufacturing. Maybe slight differences in tolerances between the angles between the old and new steering box. "Tight enough" may depend on how well the mating surfaces seal. So yes it could be that they were not tight enough.

[BigBrother-84]

Gary, when did you install the Blue Top, just after the last Truck Show?
I suppose you made some mileage since then… if so, the leak should be very recent.
IMHO, it makes sense that the oil spray source could be the bolt threads.
You probably fixed it while tightening the hose.

[Gary Lewis]

Vivek - Yes, they may not have been "tight enough".  They are now.  

Jeff - I replaced the steering box in late October, so after the show.  You can see it here.  Made a huge difference.  Probably have only 500 miles on it - a trip to Ponca City and a trip to Stillwater.

You may be right about them not being tight enough.