2016-2020 Kia Sorento Brake Fluid Type and Flush Interval

By Core Brake Parts Tech Team — Circleville, OH warehouse

The 2016-2020 Kia Sorento uses glycol-based brake fluid that meets FMVSS 116 DOT 3 or DOT 4. Both the 2016 and 2019 owner's manuals list exactly that in the Recommended Lubricants table, so a sealed bottle of either grade is correct. Kia's schedule calls for the fluid to be inspected, not replaced on a fixed mileage, which means the flush decision comes down to fluid condition, age and how hard the SUV is used.

What brake fluid the 2016-2020 Sorento takes

The 2016 through 2020 Sorento runs a conventional hydraulic system: a master cylinder with a translucent reservoir under the hood, disc brakes at all four corners, and a foot-operated parking brake that works through cables. There is no electronic parking brake on these years, so a fluid flush does not need a scan tool to retract rear caliper motors.

Here is what Kia prints in the owner's manuals for this generation:

The volume figure in that table is the amount Kia lists for the system fill, not a flush quantity. A proper flush pushes fluid through until clean fluid comes out of each bleeder, which uses more than the listed volume, so buy at least two sealed bottles of one grade before starting. Kia's online owner's manual brake fluid page states DOT 4, and DOT 4 also satisfies the DOT 3 or DOT 4 callout in the 2016-2020 manuals, so DOT 4 is the simple choice if you want one bottle that is correct for every year in this range.

DOT 3 vs DOT 4: what the numbers mean

DOT 3 and DOT 4 are both defined by the federal standard FMVSS 116. The difference that matters is boiling point. The standard sets a minimum dry boiling point for new fluid and a lower wet boiling point for fluid that has picked up water:

The wet figure is the one to think about on a Sorento that tows, carries a full third row or lives in hill country. Glycol fluid absorbs moisture from the air over time, and as water content climbs the boiling point falls toward that wet number. When fluid in a hot caliper boils it forms vapor, and vapor compresses, so the pedal goes soft or sinks during a long downhill. DOT 4 simply starts from a higher floor.

Do not put DOT 5 silicone fluid in this vehicle. The Sorento manual specifies DOT 3 or DOT 4 only, and the federal standard requires DOT 5 silicone fluid to be dyed purple precisely so it is not confused with glycol fluid, which must be colorless to amber. Kia's manual also says never to mix different types of fluid, so if you are topping up, match what is already in the system, and if you do not know what that is, a full flush with one fresh grade removes the question.

How often to flush the brake fluid on a Sorento

Kia's normal schedule for these years lists brake fluid as an inspect item, not a replace item. On the 2016 schedule the brake fluid inspection falls at 30,000 miles or 24 months and repeats on that cadence. The 2019 non-turbo schedule marks it every 15,000 miles or 24 months. The manual defines inspect as inspect and, if necessary, adjust, correct, clean or replace, so the fluid is expected to be replaced when inspection shows it is due.

In practice, the 24-month mark on the schedule is the natural time to make that call. Signs the fluid should be replaced rather than just topped off:

• The fluid in the reservoir has turned dark brown instead of clear to light amber.
• A moisture test strip or electronic tester at the reservoir shows elevated water content.
• The pedal feels softer than it used to, or fades on long grades, and there is no visible leak.
• The vehicle has never had the fluid changed and is past a few years old.
• You are installing new calipers, which opens the system anyway.

Kia's severe usage schedule also tells you to inspect the front and rear discs, pads and calipers more frequently if the Sorento is driven on dusty, muddy or salted roads, in very cold weather, on mountain roads, or while towing a trailer or carrying a roof rack. The same conditions are hard on fluid, so on a Sorento used that way, treat the 24-month inspection as a flush unless the fluid tests clean.

Checking the level and topping off correctly

The reservoir sits on top of the master cylinder in the engine bay, with MIN and MAX marks molded into its side. Kia's instructions boil down to a few rules:

• The level should sit between MIN and MAX. It drops slowly as the pads wear, because the caliper pistons move out and hold more fluid. That is normal.
• Clean the area around the cap before opening it so dirt does not fall into the reservoir.
• If the level is excessively low, or you find yourself adding fluid often, have the brake system checked. A reservoir that keeps dropping points to a leak or to pads that are worn to the end.
• Never reuse fluid that has sat in an open container. Kia notes that fluid exposed to open air for an extended time should not be used, and the federal label warning on every bottle says to keep it tightly closed to prevent absorption of moisture.
• Keep fluid off the paint. Kia warns that brake fluid contact will damage the body finish, so cover the fender and wipe up any drips with water right away.

One practical note: if the level is low because the pads are worn, topping it to MAX is not the fix. When new pads go in and the pistons are pushed back, that fluid returns to the reservoir and can overflow. Replace worn brake pads first, then set the level.

How the flush is done and what to replace at the same time

A brake fluid flush on this Sorento is a standard bleed of a four-wheel disc system with ABS. The general sequence is to remove old fluid from the reservoir, refill with fresh sealed fluid, then open each bleeder in turn while the pedal is pressed or a pressure bleeder pushes fluid through, until clean fluid with no bubbles comes out. Follow the bleeding sequence in the factory service manual, never let the reservoir run dry during the process, and torque the bleeder screws and wheel lug nuts to the values in the factory service manual. If air gets into the ABS hydraulic unit, a shop with a scan tool can cycle the ABS pump to purge it.

This is a moderate job for a home mechanic with a helper or a one-person bleeder. It is also the ideal time to look at the rest of the hydraulic system while the wheels are off:

• Hoses and lines. Kia's schedule has you check brake hoses and lines for chafing, cracks and leaks. Swollen or cracked rubber hoses should be replaced with new brake hoses while the system is already being bled.
• Calipers. A caliper that weeps fluid at the piston boot or sticks will show up as a low reservoir or uneven pad wear. Replacement brake calipers are best installed right before a flush.
• Pads and rotors. If the pads are near the wear limit, doing them first avoids disturbing fresh fluid twice. A matched set such as this 2016-2020 Kia Sorento front brake kit covers both front rotors and pads in one order, and our brake rotors collection has individual rotors if only one axle needs them.
• Hardware. Fresh clips and slide pin boots from a brake hardware kit keep the new pads moving freely.

Frequently Asked Questions

Can I use DOT 4 in a 2016 Kia Sorento?

Yes. The 2016 and 2019 Sorento manuals both list FMVSS 116 DOT 3 or DOT 4, so DOT 4 is an approved fluid for every year from 2016 through 2020. It has a higher minimum boiling point than DOT 3.

Does Kia require a brake fluid change at a set mileage on these years?

No. The normal maintenance schedule lists brake fluid as an inspect item, at 24-month intervals in both the 2016 and 2019 manuals. Replacement is called for when inspection shows the fluid is dark, contaminated or high in moisture.

Can I mix DOT 3 and DOT 4 in my Sorento?

Kia's manual says never to mix different types of fluid. If you do not know what is in the system, the clean answer is a complete flush with one grade so the whole system is on known fluid.

Why does my Sorento brake fluid level keep dropping?

A slow drop over months is normal pad wear. A drop you can see week to week means a leak at a caliper, hose, line or the master cylinder, or pads worn to the backing plate. Have it inspected before driving far, because Kia's brake warning light is tied to low fluid level.

Is it safe to drive with dark brake fluid?

Dark fluid usually means it has absorbed moisture and broken down, which lowers its boiling point. The brakes will still work in normal driving, but the margin against fade under heavy braking, towing or long descents is reduced. Plan a flush soon.

Sources

1. 2016 Kia Sorento Owner's Manual - FMVSS116 DOT-3 or DOT-4 spec, 0.41-0.45 L volume, brake fluid inspection at 30,000 miles or 24 months, severe usage brake inspection, level checking and handling cautions
2. 2019 Kia Sorento Owner's Manual - DOT 3 or DOT 4 spec, brake fluid inspection every 15,000 miles or 24 months, disc and pad inspection every 7,500 miles or 12 months, foot-type parking brake
3. 49 CFR 571.116, FMVSS No. 116 Motor Vehicle Brake Fluids - dry and wet minimum boiling points for DOT 3, DOT 4 and DOT 5, fluid color rules, container moisture warning
4. Kia Owner's Manual online - Brake fluid - current Kia guidance to use DOT 4 brake fluid and keep the level between MIN and MAX