'78 power steering troubleshoot
Searched many threads, but so many refer to manual swap or H1 upgrade.
I have stock power steering, new gearbox 5 or so years ago, no leaks. Today I drive for the first time in a month or so and steering is tough and hard to turn. Not fully manual, but maybe only 50% assist. Nothing looks like it is binding, steering shaft looks fine, plenty of fluid in the reservoir.
How can I verify if it's a pump issue or gearbox issue? Are there any tests or things that may point to the problem?
Thanks in advance for any suggestions