DeepScuba once bubbled...
I can see this could get heated, but here's my cool 2 cents..
NorthEastWr: I can't imagine, even in the good Ole US of A where somebody could hurt themselves after performing their own maintenance, and then sue the Manufacturer after getting the manual from some guys' web site.
I realize we are "Scuba blinded", but as posted by Genesis, the car makers do not do this, they cannot by law, and probably the manufacturers of dive equipment cannot by law, deny maintenance kits and parts to customers they sell to. THey do it anyways, and get away with it.
Absolutely they could sue. Whether they could win is another matter. However, consider this.
Joe the diver decides to service his own regulator. He goes to Thumper's site and downloads the manual. He reads it, acquires the parts and performs the service. Unfortunately, the manual doesn't explain everything quite as clearly as it should and he screws up. Or, if you prefer, the manual is out of date and doesn't contain a warning now included in all current manuals.
Joe goes diving. His upstream reg malfunctions and shuts down. Joe does a blow and go, embolizes and expires painfully and loudly on the deck, in full view of his pregnant wife.
Joe's widow sues everyone in sight. She alleges that the manufacturer was negligent because the manual wasn't clear enough or, in the alternate scenario, because it didn't contain the warning.
I can almost guarantee that there is a PI lawyer out there who would take that case. Moreover, they might be able to win.
One way to minimize this risk is to provide manuals only to trained techs. In addition to providing training, you can keep them on a mailing list and make sure that they have all necessary updates.
I disagree with your claim that it is unlawful for manufacturers to refuse to sell parts kits the general public. A business may choose its distribution channels and its customers. So long as the selling decision is not based on some form of unlawful discrimination, they can sell to anyone or to no one.
I believe, but am not entirely sure, that specific statutes address the sale of parts by automobile manufactuers. Even so, there are some parts that cannot be obtained from auto parts stores and that must be obtained from a dealer.
Looking at the potential harm to the general public is not the correct question. The appropriate question is whether a business may decide to whom it will sell.
In the absence of discriminatory conduct or a statute, the answer in this country is yes. Businesses still have some rights.