Texas summers are harder on vehicles than mild climates in measurable, predictable ways. A Seguin summer combines 100°F+ daily highs, intense UV exposure, and (in a typical year) at least one stretch where vehicles sit in 110° parking lots all day. Vehicles that would last 10 years in Minnesota fail at 7 here, and the things that fail first are predictable. Here's what to check before July and what we look at when customers bring their vehicles in for summer service.
A/C: not optional
Auto A/C systems lose 5-10% of their refrigerant charge every year as a normal function of seal aging. By year three or four, a system that was working fine new is now blowing 8-10°F warmer at the vent than it should. Add Texas heat to that gap and the difference between "cool" and "useless" becomes obvious in July.
Schedule an A/C performance check before May:
- We measure pressure on both sides (high and low) and compare against the factory spec for your vehicle and the ambient temperature
- We test compressor function, clutch engagement, and condenser airflow
- We check the cabin air filter (often the cause of weak airflow, regardless of refrigerant)
- If refrigerant is low, we pull the system to vacuum, hold to confirm no leak, then recharge to factory weight
If you're already noticing weaker cool at idle (especially in traffic on I-10 or US-90), or the system cycles rapidly, that's a refrigerant or compressor sign — not something that fixes itself.
Cooling system: where Texas wins
The cooling system circulates coolant through the engine, radiator, heater core, and back, keeping engine temperature in a narrow operating window. Texas summer pushes the system harder than any other condition. Things to check:
- Coolant condition and level — old coolant loses its corrosion-inhibitor additives; the fluid that's clear-pink today is the rust-bath that fails a water pump next year
- Hoses — squeeze each upper and lower radiator hose; bulges, soft spots, or oil-soaked rubber mean replacement is overdue. The belts and hoses page has the full inspection list
- Water pump — a leaking weep hole or a noisy bearing means the pump is finished. Replace before it fails in stop-and-go traffic
- Radiator fan operation — should kick on with the A/C and again as temperature climbs
Battery: heat is worse than cold
Most people think of cold as the battery killer, but heat is harder on the lead plates and electrolyte. Texas batteries average 3-5 years where northern batteries average 5-7. If yours is past four years old or you've been parking in the sun all summer, get it tested. Free battery testing is standard at any service visit — battery replacement covers what's involved.
Tires and pressure
Hot pavement plus underinflated tires equals blowouts. Check your pressure cold, monthly, especially before any road trip. The TPMS light goes off at about 25% underinflated — by then you're already losing tread life. The TPMS service page covers sensor issues.
If your A/C is weak or your temperature gauge has been climbing, don't wait for July. Request an appointment or call (830) 379-4840 and we'll get you ready for what Texas summer brings.