My other thought is that some medications have short term memory problems as a side effect. Is your brother on any medications ? If her is, he could go to www.drugs.com , type in the name of the drug and see if memory issues are a side effect. Finally, is your brother having sleeping problems ?
For some vehicles, you're advised to change the coolant every 30,000 miles. For others, changing the coolant isn't even on the maintenance schedule. For example, Hyundai says the coolant (what many refer to as antifreeze) in most of its models should be replaced after the first 60,000 miles, then every 30,000 miles after that. The interval is every 30,000 miles on some Mercedes-Benz models, but on others it's 120,000 miles or 12 years.
If your car doesn't have a reserve tank for the Antifreeze/Coolant, pour the fluids directly into your radiator. To check the fluids directly in the radiator, look into it. You should be able to see the fluid.f they are not,continue to refill with the instructions below. To change the Antifreeze/Coolant levels, first buy your preferred brand of Antifreeze/Coolant. Make sure your car engine is cool. Open the hood of your car and find the coolant reserve container.