Power Steering question

[rstallings]

I resealed the PS box in my 86 300e about 6 months ago. I also changed all of the fluid and cleaned the lines out.

All was well until I drove to Colorado, and started the vehicle up in cold weather. THe pitman arm shaft seal totally let go, and all of the fluid went away.

The lip of the blown seal came out due to pressure from the inside of the box. I decided to cop out and do the easy thing and replace the lip seal and O-ring on the lower cover. All well for a couple of more weeks, then I drive to the airport at 5:30 in the morning, and it happens again.

Is there a PR valve somewhere that is sticking when it's cold, or did I nick a seal when I built the box? It seem odd that there are no leaks at all untill it's cold, then total fluid loss.

Can you tell if there is a nick or burr on the sealing surface of the shaft? If you can figure a way to polish the shaft at that point, you might be able to get by without pulling the whole thing apart.

That seal is a common leak point on these systems BTW. I've never known of any pressure relief valve problems but that doesn't mean there can't be one.

Good luck,