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Coolant does not just keep an engine from freezing. It also carries additives that stop corrosion, and those additives wear out before the color changes. Route 66 Auto Repair in Upland analyzes your coolant for protection level, acidity and stray electrical voltage, so the decision to service it is based on readings instead of a sticker or a guess.
What does a coolant analysis measure?
- Freeze and boil protection with a refractometer
- pH level, which shows whether the coolant has turned acidic
- Additive condition with test strips
- Stray voltage in the coolant, a sign of electrical or corrosion trouble
- Color, clarity and any particles or film
Why test instead of going by color?
The additives that protect aluminum, solder and gaskets get used up slowly. Once they are gone, coolant turns acidic and starts to eat metal from the inside, which leads to pinhole leaks, clogged radiators and failed water pumps. The color can stay bright the whole time. A refractometer reading tells us the mix strength, and a pH strip tells us whether it has turned.
Stray voltage is a less-known test. A meter probe in the coolant can pick up voltage from a poor engine ground, which speeds up corrosion. If we see it, we note it and suggest checking grounds through electrical system diagnostics.
Our fluid analysis process
Step 1: Sample cold
A sample is drawn from the radiator or reservoir with the engine cool.
Step 2: Measure
Protection, pH and additive readings are taken and compared with the coolant type your engine uses.
Step 3: Voltage check
With the engine running, a meter checks for stray voltage in the coolant.
Step 4: Recommend
Results go on the repair order, with a service recommendation only if the readings call for one.
What's included in fluid analysis
Included on the work order
- 01Refractometer freeze and boil reading
- 02pH and additive test strips
- 03Stray voltage test
- 04Visual check for oil, rust or sludge
- 05Written results and recommendation
What results call for action now?
Need now: call
- Acidic pH or heavy rust
- Oil or sludge in the sample
- Measurable stray voltage
Need later: book
- Protection on the weak side of the range
- Additives near the end of their life with a normal pH
How pricing and timing work
Fluid analysis is a quick test, often done with an oil service or inspection. The fee is stated at the counter before we start and applies to approved related repair. If a service is needed, you get a written estimate for a coolant system service or a flush. AAA members get 10% off parts and labor, up to $75.
After the analysis
Keep the readings with your records so the next test can be compared. If oil or bubbles showed up, a coolant system contamination test is the next step. Call (909) 608-7699 to schedule.


Frequently asked questions
Can I test my coolant with store-bought strips?
Strips give a rough idea. A refractometer and a voltage check add accuracy, and we compare results to the coolant type your engine needs.
How often should coolant be tested?
A test at each oil service on an older vehicle is a good habit. Newer vehicles with long-life coolant still benefit from a yearly check.
Is a fluid analysis different from a contamination test?
Yes. Analysis checks whether the coolant itself is still protecting. A contamination test looks for oil, gas or other fluids that got in.
