Follow Normal Maintenance Schedule if the vehicle is usually operated where none of the following conditions apply. If any of the following conditions apply, you must follow the Maintenance Under Severe Usage Conditions.
For additional information or assistance see your authorized HYUNDAI dealer.

I : Inspect and if necessary, adjust, correct, clean or replace.
R : Replace or change.
*1 : If TOP TIER Detergent Gasoline is not available, one bottle of additive is
recommended. Additives are available from your authorized HYUNDAI dealer along with
information on how to use them. Do not mix other additives.
*2 : The drive belt should be replaced when cracks occur or tension is reduced excessively.


*3 : Fuel filter & Fuel tank air filter are considered to be maintenance free but periodic inspection is recommended for this maintenance schedule depends on fuel quality. If there are some important safety matters like fuel flow restriction, surging, loss of power, hard starting problem, etc. replace the fuel filter immediately regardless of maintenance schedule and consult an authorized HYUNDAI dealer for details.
The following items must be serviced more frequently on cars normally used under severe driving conditions. Refer to the chart below for the appropriate maintenance intervals.
I : Inspect and if necessary, adjust, correct, clean or replace.
R : Replace or change.


Severe Driving Conditions
A- Repeatedly driving short distances of less than 5 miles (8 km) in normal temperature or less than 10 miles (16 km) in freezing temperature
B- Extensive engine idling or low speed driving for long distances
C-Driving on rough, dusty, muddy, unpaved, graveled or saltspread roads
D-Driving in areas using salt or other corrosive materials or in very cold weather
E-Driving in sandy areas
F - Driving in heavy traffic area over 90°F (32°C)
G- Driving on uphill, downhill, or mountain road
H-Towing a Trailer, or using a camper, or roof rack
I -Driving as a patrol car, taxi, other commercial use or vehicle towing
J - Driving over 106 mph (170 km/h)
K-Frequently driving in stop-and-go conditions
Hyundai Elantra AD (2016-2020) Service Manual: Vacuum Pump Components and Components Location
Components
[UII 1.6]
1. Camshaft bearing cap2. Camshaft3. Camshaft sprocket4. Vacuum pump5. Vacuum pump gasket
...
Hyundai Elantra AD (2016-2020) Owners Manual: Warning and Indicator lights. Parking Brake & Brake Fluid Warning Light
Information
Make sure that all warning lights are OFF after starting the engine. If any
light is still ON, this indicates a situation that needs attention.
Supplemental Restraint System Warning Light
This warning light illuminates:
Once you set the ignition switch or the Engine Start/Stop ...