It's scary. You say it is about 30 years old and you still have the instruction booklet. That's unheard of. Please post the model number - that will help.

Yes, we still have the original instruction manual......but its in hieroglyphics. :)
Its a Sears and the model number is 139.53200

I looked up your manual and the instructions you want are on page 30. With pictures. Step 4 is what you need.

One of the statements is "The door must reverse on striking the obstruction." This is a little misleading. The door actually stops on the obstruction momentarily and then reverses to the open position. If you follow these instructions and it doesn't reverse you will need help. You must live in California. I haven't heard of anywhere else that the realtor advises this.

Thanks Don,
Actually, my manual says to put something that is 1" high on the ground and see if the door reverses when it hits it.
But....don't we want it to reverse if any upward pressure is put on the door anytime during its downward trek? That's how I was testing it yesterday. I would press the button to lower it and then run over to it and try to stop it with my hand. Maybe I have a misconception about how this works. But if the strength of my hand/arm couldn't stop it.......couldn't it still hurt something/somebody?

What you are doing is correct but it does press down pretty hard before reversing. Adjusting it on a 1 or 2 inch board will be the same for the entire travel of the door. The door will probably hurt a small child or animal but will not trap them which is what was happening in the beginning. Your opener was built before they came out with door sensors which makes them even safer.

Thanks don!
I'm curious as to why not having a sensor would make it safer?
Also......we want things to pass inspection. We're pretty mechanically-challenged. Can we put something along the track to make it slide better? What could we use?
I appreciate your help!

I should have reread that sentence I wrote about the door sensors. It reads the way you took it but what I meant to say was the door sensors make it much safer. Don't put anything on the track but you can use silicone spray on the rollers. Spray the bearings.

Thanks don.