Why does power steering pump squeal

[Arl37]

69 C 10 with after market power Steering. Pump (belt) squeals on lockup when turned to max turn. My other cars don’t do this. Something wrong with pump?
Your thoughts please.

[Steeveedee]

Your other vehicles may have a pressure relief to avoid that. Don't hold the steering wheel that hard on the stop, ever. In the hydraulic industry that is called "two-blocking" because the components are against both hard stops (blocks). If you do this enough times, the high pressure hose may burst, and the fluid spraying all over a hot exhaust manifold may cause a fire that burns your truck to the ground.

[FirstOwner69]

Belt may squeal in normal operation if it's not tight enough. But, as noted above, "Don't hold the steering wheel that hard on the stop". It's not wise even if the belt is tight and doesn't squeal. May even be harder on the pump.

[Steeveedee]

Originally Posted by FirstOwner69

Belt may squeal in normal operation if it's not tight enough. But, as noted above, "Don't hold the steering wheel that hard on the stop". It's not wise even if the belt is tight and doesn't squeal. May even be harder on the pump.

Right. Ask me how I know about that...except I was lucky that is was just a lot of smoke, in my case. I've seen vehicles burn to the ground with this.