Steering input shaft leak

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dbryan23

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Georgia
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Donald
Truck Year
1978
Truck Model
K10
Engine Size
400 SBC
I'm having a hell of a time trying to fix a steering gear box input shaft leak on a 1978 K10. I replaced the seal, the O-ring and the dust seal, refilled the reservoir, cycled the steering for a while and thought everything was good. Then after a few days of sitting there was suddenly a puddle. I pulled it back apart and everything seemed to be in good shape. It didn't look like I damaged the seal when putting it back together or anything. I drove the seal in a little deeper thinking maybe it would seal better if it was contacting a different part of the input shaft. The shaft itself looked fine... no noticeable groove or pitting or anything. I cleaned it up as best I could, put everything back together and refilled the system. Again it looked good for a couple of days. No noticeable leak. Came back from being out of town this weekend and there's a puddle. And it's definitely coming from the input shaft. I had everything clean and dry, and now there's fluid welled up around the bottom of the input shaft.

The situation has me stumped. I ran the truck for a while, went lock to lock multiple times without any leaking both times after refilling. Then it randomly just starts leaking a few days later without driving the truck any. It seems like it would have leaked almost immediately while the truck was running and the steering wheel was being turned back and forth.

Anybody have a similar experience or any advice on what I might do to fix this? I've seen a lot of people say that remanufactured gear boxes are just about as likely to leak as old ones, so I'd rather not drop the money on a rebuilt unit just for one leak. Is there some little trick that I'm not aware of that gets these old Saginaws to stop leaking? Is there supposed to be a pressure relief valve that releases pressure when the truck isn't running so there's not just constant pressure on the seal?

Is the steering shaft solid or hollow? Is there a way for fluid to leak from inside the steering shaft? It almost seems like fluid is leaking from the little pin in the end of the shaft... that part that fits into the rag-joint. I assumed the shaft is solid and doesn't have fluid inside it, though.

Are there different seal sizes to match input shafts with slightly different diameters? I couldn't find any alternate part numbers. Or does anybody recommend a certain brand that works better than other brands.

I've got this truck down to where there are almost no leaks at all. Walking out and seeing a power steering fluid puddle is really irritating me.
 

PrairieDrifter

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I've used a gates kit and a napa kit. One of 'em tried to weep ever so slightly for about a week maybe two, it's been dry ever since. I daily drive mine though.

I'd say put some miles on it before you do it again. A new seal and an old sealing surface can take some time to mate to each other, now and again.

Did you lube the seals before going together? Is the sealing surface in good shape? I highly doubt the input shaft is hollow, fluid likes to creep even without driving. Even a windy day just being parked can throw fluid around if it's leaking
 

dbryan23

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Donald
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K10
Engine Size
400 SBC
I've used a gates kit and a napa kit. One of 'em tried to weep ever so slightly for about a week maybe two, it's been dry ever since. I daily drive mine though.

I'd say put some miles on it before you do it again. A new seal and an old sealing surface can take some time to mate to each other, now and again.

Did you lube the seals before going together? Is the sealing surface in good shape? I highly doubt the input shaft is hollow, fluid likes to creep even without driving. Even a windy day just being parked can throw fluid around if it's leaking
Thanks. I was kind of thinking the same thing about just needing to drive it around some to maybe heat up the rubber of the seal a little and let it conform better to the shaft. I've got to finish up a couple of other things before I can drive it, so all I've done is cycle the steering a few times.

I did lube the seal with ATF before installing, and the shaft itself looks like it's in great shape. I was just curious if this was one of those things where every experienced square body owner was like "Only use such-and-such brand seals! All other will leak!" or something like that. Or if even there's a certain seal with a slightly tighter ID that is better.
 
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PrairieDrifter

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Thanks. I was kind of thinking the same thing about just needing to drive it around some to maybe heat up the rubber of the seal a little and let it conform better to the shaft. I've got to finish up a couple of other things before I can drive it, so all I've done is cycle the steering a few times.

I did lube the seal with ATF before installing, and the shaft itself looks like it's in great shape. I was just curious if this was one of those things where every experienced square body owner was like "Only use such-and-such brand seals! All other will leak!" or something like that. Or if even there's a certain seal with a slightly tighter ID that is better.
Are you running atf in the whole system? Gates is usually my go to brand for hoses and belts. They do offer some seals and whatnot.

If you really wanted to find a different seal I would imagine other Saginaw boxes are pretty much all the same basically, with slight variations. I'm sure there's some kind of reference guide somewhere.

But in the end I would try and get it settled in first. I would use power steering fluid, not atf.
 

dbryan23

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Location
Georgia
First Name
Donald
Truck Year
1978
Truck Model
K10
Engine Size
400 SBC
Are you running atf in the whole system? Gates is usually my go to brand for hoses and belts. They do offer some seals and whatnot.

If you really wanted to find a different seal I would imagine other Saginaw boxes are pretty much all the same basically, with slight variations. I'm sure there's some kind of reference guide somewhere.

But in the end I would try and get it settled in first. I would use power steering fluid, not atf.
Sorry... I meant PS fluid. I was messing with the transmission yesterday before I posted, and I guess I just had ATF on the brain. Although I'm pretty sure it did have ATF in it when I bought it (unless there's some kind of red PS fluid that I don't know about). It also had ATF in the transfer case, but I changed that back to 90 weight. I guess the previous owner got a deal on ATF in bulk. At least the radiator had actual coolant and water in it.
 

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