When to Replace Your Coolant Storage Tank
Recognizing the signs of a failing coolant tank to prevent engine damage and leaks
Visible Physical Damage
One clear sign is visible physical damage. Inspect the tank regularly for cracks, splits, or bulges, especially around seams, hose connections, and the base.
- Even small cracks can expand over time, leading to coolant leaks
- Leaks reduce system pressure and cause overheating
- Look for wetness or coolant residue around the tank
- These signs may indicate a developing leak that requires immediate replacement
Immediate Action Required
If you notice visible cracks or persistent coolant residue, replace the tank immediately to prevent engine damage from overheating.
Material Degradation
Over time, exposure to heat, coolant chemicals, and UV rays can cause tanks to deteriorate. Look for these signs of material degradation.
Plastic Tanks
Become brittle, discolored, or warped. Check for faded plastic, chalky residue, or a sticky texture indicating material breakdown.
Metal Tanks
Show corrosion, rust, or pitting, especially in areas where coolant pools or moisture accumulates, compromising structural integrity.
Pro Tip
Regularly clean the exterior of your coolant tank to remove contaminants that can accelerate material degradation.
Performance Issues
Performance issues also warrant replacement. Watch for these warning signs that your coolant tank may be failing.
- Frequently needing to top up coolant without obvious leaks elsewhere
- Slow, hard-to-detect leaks from the tank
- Inconsistent pressure in the cooling system
- Overheating, coolant boil-over, or temperature warning light activation
- Cloudy or unreadable level markers making it impossible to monitor coolant levels
If you experience any of these issues, inspect your coolant tank immediately and replace it if necessary.
Age & Maintenance History
Consider the tank's age and maintenance history when deciding whether to replace it.
- Most coolant storage tanks last 5–10 years, depending on material quality and usage conditions
- If your vehicle is older and the tank has never been replaced, proactively inspect it for wear
- Previously repaired tanks (with sealants or patches) are likely approaching the end of their reliable lifespan
- Replace with a new unit to avoid unexpected failures
Preventative Maintenance
Even without obvious signs of damage, consider replacing your coolant tank every 8 years or 100,000 miles as preventative maintenance.