* Hose Clamp Failure: The most common reason. Cold weather makes rubber hoses and clamps brittle, leading to cracking and loosening. Even new clamps can fail if not properly tightened or if the hose itself is damaged. Check for cracks in the hose near the fitting and ensure the clamps are properly seated and tight enough. Consider upgrading to stronger, more durable clamps like worm-gear clamps instead of standard screw-type clamps.
* Fitting Corrosion/Damage: The fitting on the gearbox itself might be corroded, damaged, or worn. Corrosion can create a rough surface, preventing a tight seal with the hose. Inspect the fitting closely for any pitting, damage, or rust. If damaged, it will need to be replaced.
* Hose Degradation: The power steering hose itself might be degrading faster than expected. Age, exposure to elements, and the harsh chemicals in power steering fluid can cause the hose to become brittle and prone to cracking or separating from the fitting. Ensure you are using a high-quality, correct-specification replacement hose. Cheap hoses often fail prematurely.
* High Pressure System Issues: While you replaced the pump, there could still be underlying issues causing excessively high pressure within the system. A problem with the power steering rack, valve, or even a partially blocked line could lead to higher than normal pressure, forcing the hose off the fitting. This is less likely if the problem only started after the pump replacement but should be considered.
* Incorrect Hose Installation: If the hose wasn't properly installed during the pump replacement, it might not be seated correctly on the fitting. Even a slight misalignment can cause it to blow off under pressure. Double-check that the hose is properly seated and that there's no kinking.
* Temperature-Related Issues: The cold weather exacerbates the problem because the rubber hose and seals become stiffer and less pliable, making them more susceptible to cracking and loosening. The power steering fluid itself can also thicken in cold temperatures, increasing the pressure in the system.
Troubleshooting Steps:
1. Visual Inspection: Carefully inspect the hose, clamps, and the fitting on the gearbox for any signs of damage, corrosion, or wear.
2. Clamp Check: Ensure all clamps are properly tightened and secure. Consider replacing all clamps regardless of their apparent condition.
3. Hose Replacement: Replace the hose with a high-quality, correct-specification hose. Don't skimp on this; a cheap hose is likely to fail again.
4. Fitting Inspection: If the fitting on the gearbox shows any damage, it will need to be repaired or replaced.
5. Pressure Test: If the problem persists, a pressure test of the power steering system might be necessary to rule out high-pressure issues in other components. This requires specialized equipment.
Addressing each of these possibilities systematically will greatly increase your chances of finding and fixing the root cause of the recurring problem. If you are not comfortable working on power steering systems, it's best to have a qualified mechanic diagnose and repair the issue.
