Steering: Avanti power steering leak

[GinettaG12P]

The power steering control valve on my 1963 Avanti is leaking. It drips from the end with the bolted-on cap. I looked at the shop manual and it appears that I can replace the seal while the control valve is still on the car. Is that possible? How difficult is it to remove the "hug locknut"? Any thoughts/suggestions, etc? Thanks.

[karterfred88]

Easy job, but messy. Buy the reseal kit, take the two screws from the cap, remove the two bolts holding the sleeve to the valve, remove the locknut (hugnut) on the shaft end, being careful to keep the spring retainers, washers and spacer in the right order. Move the pitman arm so you have room to slide the shaft out of the valve body completely. Push the spool valve towards the cap end and remove, making sure you get the backing rings from both sides and noting which direction the spool was oriented (by noting the carved out area between the smooth areas) so it goes back in the right direction. Then put the sleeve bolts back in and reattach to the control valve body-- make sure it is seated before tightening the bolts ( watch for a spacer and washer which may fall out, just put them back in). Place the seal on the spool making sure the lip faces the center of the spool, slide on the backer washer and slide the spool with backer and seal in place over the shaft and into the valve body. Place the other seal on the spool, facing the lips into the center then message the seal lip into the valve body carefully ( I use a blunt tooth pick) making sure the lip goes towards the center, add the backing ring and push the spool in as far as you can. Add the washers spring retainers, spacer, spring retainer washer and hugnut. Tighten down snug, then back off one flat. Put the cap back on, make sure the sleeve bolts are tight and away you go. The instructions say you can do it all from the cap end, and you can, but the challenge is to snag that backing washer way down in the valve body from the valve with the spool out, having to make some kind of hook that will fit between the center shaft and the backer washer, and be hooked enough to catch the backer washer and get it to come out without jamming. Have done it both ways, got lucky and didn't. If the hook method doesn't work, then just pull the two sleeve bolts, slide the valve housing past the shaft end, retrieve or push it out the other end and proceed as above. Have fun!!!!
Check the spool and housing for rust and corrosion, make sure the seals are "snug" on the spool and the lip fits snugly in the valve body. I finally figured out mine was "cleaned up" from some corrosion and turned too far for the seals to seal. Had to send it out, after resealing 4 times with the standard seals.

[Skip Lackie]

To re-emphasize the above (excellent) advice: keep everything clean, make sure that everything goes back in in the same order, and facing the same way. Spread out a piece of newspaper or cardboard and lay everything on it in order.

[duncan1951]

Not sure valve has been put back correctly (by me) please explain in detail the following "noting which direction the spool was oriented (by noting the carved out area between the smooth areas) so it goes back in the right direction."
If installed backwards can this result in leakage as well?

[karterfred88]

Not usually, it is supposed to go in one way per the manual but seems to work either way. Leaks are usually caused by the seals not working well due to wear on the spool ends or inside the housing, or if you just put new ones in it, it could be due to the thin backing washers being misaligned to the seals. Also if the seal lips are pointing to the ends instead of the center they will leak-badly. Sometimes the spacer washer 1308-93 on valve diagram moves and cocks so the inner seal backing washer (1308-91) doesn't push on the seal right and lets it leak into the flanged tube area. Since no oversized seals are available from vendors, there is no way to reseal it at home if fluid is getting by new seals. There are fixes available by machining the spool ends and using different seals, best left to a rebuilder.
The "correct direction" for the spool is with the depressed area towards the cap, see arrow.