* Power Steering Pump Failure: This is the most likely culprit. A failing pump can generate excessive pressure. Look for signs of leaking or whining from the pump itself. Internal wear within the pump can cause it to struggle and build pressure.
* Blocked or Restricted Lines: Clogged or kinked power steering lines (high-pressure or return) can restrict fluid flow, forcing the system to build pressure. Inspect the lines carefully for any damage, kinks, or debris.
* Seized or Binding Steering Gearbox: A problem with the steering gearbox itself, such as a seized or binding part, will create high resistance and thus high pressure in the system. This is often accompanied by difficulty steering.
* Overfilled Reservoir: While less likely to cause *blowing out*, an overfilled reservoir can still contribute to pressure buildup, especially when the fluid warms up and expands.
* Faulty Power Steering Pressure Relief Valve: This valve is designed to release excess pressure. If it's malfunctioning, pressure can build up dangerously.
* Incorrect Fluid: Using the wrong type of power steering fluid can cause problems. Consult your owner's manual to ensure you're using the recommended fluid.
Troubleshooting Steps:
1. Check the fluid level: Is it significantly overfilled? If so, drain some out to the correct level.
2. Inspect the power steering pump: Listen for unusual noises (whining, groaning). Look for leaks around the pump itself and its connections.
3. Inspect the power steering lines: Look for kinks, bulges, cracks, or rust. Pay close attention to both the high-pressure and return lines.
4. Check for leaks elsewhere in the system: A leak elsewhere can lead to a low fluid level and cause the system to overwork.
5. Test the steering: Is the steering unusually stiff or difficult? This could indicate a problem with the steering gearbox.
6. If all else fails: It's best to take your truck to a qualified mechanic specializing in older vehicles. They have the tools and expertise to diagnose the problem accurately and safely.
Safety Note: Be very careful when working on the power steering system. The high-pressure lines can release fluid under significant pressure, causing injury. Always wear safety glasses and gloves. Let the system cool down before working on it.
