We got a used maytage protable dishwasher, im not sure of the model but it will not hook up to the sink the adapter just falls off

If your machine adapter that hooks up to your sink faucet has 4 white plastic jaws on the interior where the faucet adapter fits then you can get a rebuild kit that will include those plastic jaws, the seal, a spring, and a new retainer clip.. after a period of time those jaws wear and will no longer grip the metal adapter securely..
if i had the model number of your unit i could look that up for u, but you can probably go to sears.com or wherever you might buy appliance parts locally and they can look it up and provide them for you.. if not let me know, i have some at the shop, just not here at home with me. i'm sure if necessary we could look up, sell, and ship them to you but with shipping the cheap little part gets sorta spensive from here in ny.
best of luck,
ttfn