Here is a list of what I've done:

Disc brakes on original spindles
Heavy duty solid tie rod
Rebuilt 1980 Toyota steering sector
Saginaw (rebuilt) pump
Summit Steering column, Borgeson DD to Toyota spline U Joint
New King pins, new tie rod ends, rebuilt drag link
New spring bushings
4 degrees of positive caster (top of axel towards cab)
1/8" toe in
What's left is stock

Problem, hissing at the wheel, not bad but is there.
If I take my hands off the wheel it goes straight as an arrow for at least 100 feet.
Little play in steering wheel, maybe an inch either way.
The truck is squirrely,always correcting and over correcting the steering
Should also state the steering wheel does not return to straight after making a turn.
The only thing I haven't done yet is to shimm the pressure valve in the pump to reduce the pressure, with the hissing I think I have too much pressure. Will the pressure being too high cause the over correcting? I thought caster would do that along with making the wheel return to straight after making a turn.

Any suggestions are welcome, it's killing me!
-Doug

 

Did you bleed the air out of the system?

 

Drove it enough that it should be OK, no bubbles in the pump.
But thanks for asking!

 

I am sure more knowledgeable will chime in, but my understanding is that they need lots of camber (I think I read about using two of the 3 or 4 degree shims).

 

I'm thinkin steering box issues, or not enough caster. have you had it on an alignment machine? Cure the caster then look at the Box/pump. Good luck.

 

I'd first reduce the pump pressure rebuilders tend to set them to deliver full pressure so customers are "impressed" with steering ease improvement. Easy, 6.00 investment if it doesn't fix it. Will reduce sensitivity possibly fix hissing (at what wheel, steering wheel or wheel and tire?) Keep adjusting spring shim pack until it just steers with moderate effort at slow speed (not standing still) not "finger tip". If it still doesn't return then add a pair of caster shims and see if that fixes it, otherwise box may be adjusted too tight. Bleed system by turning fully to one side, hold for 10 seconds, turn fully other direction, hold for 10 sec, repeat twice more. Refill rez and repeat if level dropped.

 

Thanks, I'll try the pressure adjustment. Yes the hissing is at the steering wheel, sorry I didn't make that clear. This is the second sector I've tried the first was a wrecking yard unit and the second a rebuilt. The second seemed to be a little better but not much. I have a set of 1.5 degree shims and a set of 4 degree shims. I tried both that didn't do the trick so I went back to the 4's. I also extended the spring pack bolt to make sure it was landing solidly in the axel. With the 5.5 degree shims installed there wasn't much difference if any between the 4's and the 5.5. These were guestimates, I'm going to get a protractor today and check exact amount of caster the axel is set to. This is puzzeling to say the least.

 

Have you checked the bolts are tight? As for the hissing, it sounds like high pressure.

 

I tried the lock to lock 3 times and paused at each lock. Helped a bit but still over correcting and yes the hissing is probably too much pressure. Anybody had this issue before? Thanks for all the replies!

 

Caster measured 3.8 degrees.

 

That should be enough caster. I'd look elsewhere. Are you using radial tires, check the air pressure 28 -32# cold? Not using any excessive offset wheels?

 

Pretty much a stock wheel, 15" with radial tires. Off set is about center of the wheel. They are only 6" wide wheels. I ordered a kit to reduce the pressure on the pump hoping that will get rid of the issue, grasping at straws here. I tried increasing the toe in, didn't do much so I went back to 1/8", went up to a 1/4" with no difference. When the engine is running there is about an inch of play in the steering wheel, I tried to set the lash a little tighter but it was already set pretty good. If I tighten it up any more I'd need a big wrench as it was tight, went back to the rebuilders setting on the lash. If it's not the pressure I think it might be a bad sector. Thanks for your input. This setup should be pretty tight right?

-Doug

 

There should be very little free play with the Toyota box other than any slop in the steering parts themselves. Don't overtighten the adjustment or that can cause the steering to bind up. You might want to check on Toyota truck sites to see if anyone has the factory shop manual adjustment procedure. Unfortuantely some rebuilders just replace the external shaft seals and tighten the adjustment as far as it will go and call it good. They aren't fun to take completely apart and put back together, with all the loose recirculating bearing ***** in it.

Oh, one more thing: what steering column are you using? When you put the shaft into the U joint did you push the shaft in as far as it would go? If you do/did, the shaft will bottom out against the U joint trunion, the piece in the center the U joint that allows it to flex. When that happens the U joint will bind and catch as it turns and flexes. You can try loosening the set screws or bolts that attach the U joint to the shaft, the lower floor support and the dash drop, pull the column back a 1/4" and retighten to see if it works better. If it does help, and you drilled depressions for the set screws, pull the column out and grind or cut a 1/4" off the end of the shaft. Round off the corner after you cut it.

 

I would check the box adjustment for the non returning to center (also make sure everything turns smooth on the steering linkage). As for the hissing, mine does it also and I have a Ford pump. I used an adjustable power steering pressure reducer to play with the pressure, but it still hisses. I have to correct mine also while driving but I haven't played with the caster yet.

 

That's something I didn't think about! Yes I did bottom it out against the U joint, I'll check it out after work today. I really hope that's it, it's a real PIA to remove and replace. I have a call into the rebuilders explaining the problem. I'm afraid it has to come out and be replaced. Thanks for your help!
Thanks everyone for your input as well, I'll post what the fix is.
-Doug