Tech Tip: Kia 4WD Control Vacuum Line Service

Tech Tip: Kia 4WD Control Vacuum Line Service

You may encounter a Kia vehicle on which the four-wheel-drive mode is inoperative (diagnosed either during or after replacing knuckles and hub seals) due to insufficient vacuum being applied to the hubs. In some cases, moisture has entered the vacuum system and the vacuum lines have become corroded, plugged or have developed a leak ....

Four-wheel-drive mode inoperative (diagnosed either during or after replacing knuckles and hub seals) due to insufficient vacuum being applied to the hubs. In some cases, moisture has entered the vacuum system and the vacuum lines have become corroded, plugged or have developed a leak.

Corrective Action:
Verify that with the 4WD mode selected, vacuum is present at the T-fitting downstream from the solenoid. If not, diagnose and repair as required, otherwise use the following procedure to replace the vacuum lines:

Note: Refer to section 4360 of the parts catalog for part numbers, etc. Procedure applies to right-side line; the left side needs no further information.

Service Procedure:
1. Disconnect and remove the battery and battery tray.

2. Leaving ground cables attached, remove the clamp bracket from the battery tray bottom and move it out of the way.

3. Remove the plastic air resonator and disconnect the throttle cable (plus A/T control cable, if equipped).

4. Disconnect the MAF and IAC connectors, and 6 mm bolt holding the DLC and MAF brackets to the air cleaner housing.

5. Disconnect the air intake tube from the throttle body, and the MAF sensor from the air filter housing.

6. Remove the tube, duct and sensor assembly and set aside.

7. Loosen the rear engine hanger bracket and front surge tank support bracket.

8. Disconnect the coolant lines from the throttle body or (alternatively) remove the throttle body from the surge tank but leave the coolant lines attached. Remove the surge tank.

9. Cover the intake to prevent anything from falling in.

10. Mark the steering column shaft and coupling for later reference. See Photo 1.

11. Loosen the clamps on both sides of the coupling and slide the coupling back on intermediate shaft, disconnecting it from the steering column.

12. Disconnect the vacuum hoses in the right wheel well and from the T-fitting below the 4WD solenoid on the driver’s side of the engine compartment.

13. Pry the vacuum line loose from the four plastic retainer clips; two on the bulkhead, two on the inner wheel wells.

14. Using the slack in the harness and carefully bending the vacuum line only as necessary, free the line from behind the harness bundle against the RF inner wheel well.

15. Free the vacuum line from behind the brake line attached to the (outboard position) of the differential pressure valve.

Note: Try leaving the old line intact while removing it and carefully observe the “route” you use to get it out. This will serve as “practice” that will come in handy when you install the new one.

16. Starting from the driver’s side, free up the old line and move it up until it clears the cylinder head at the location of rear engine hanger. Move and “snake” the line carefully as required to free it up and pull it out.

17. Install the new line the same way, and assemble everything in reverse order. Observe the reference mark on steering shaft when reassembling.

18. Test drive and check 4WD operation.

Courtesy of Kia Motors America.

You May Also Like

Mazda Blind Spot Monitor Calibration (VIDEO)

Joe Keene discusses how to calibrate the blind spot monitoring system on a 2020 Mazda 6 Grand Touring.

Whether or not the blind spot sensor itself is damaged, if the rear fascia comes off, a calibration is called for.

Using both the sophisticated electronics of Hunter’s ADASLink diagnostic scan tool and old-school measurements with string and a plumb bob on a 2020 Mazda 6, Joe Keene demonstrates that the key to all ADAS calibrations is precision – and particularly so with blind spot sensors. ADASLink’s onscreen instruction ensures that precision by eliminating guesswork and providing an accurately performed and thoroughly documented calibration for more than 25 million vehicles.

Akebono Releases ProACT Brake Pad Kits for Honda, Ford, Lincoln and Toyota

Electronic wear sensor and premium stainless steel abutment hardware is included in the kits that require it. 

How to Maximize Cooling System Efficiency (VIDEO)

Do everything you can to help the system operate as intended. This video is sponsored by Rislone.

MSU Joins Statewide Effort to Promote EV Mobility Careers

A new a public-private partnership has been established to recruit electric vehicle and mobility talent to Michigan.

Decrypting Brake Pad Edge Codes

Learning the cryptic codes on the brake pad or shoe will tell you a lot of information.

Other Posts

Auto Pros on the Road: Curt’s Service

Detroit-area full-service facility completed an “all-green” expansion for comfort and safety of techs and clients.

Bartec USA To Host TIA’s ATS Class at Their Facility

Classes will be held from April 25-28.

J.D. Power Study: EV Market Growth Fuels Owner Satisfaction

Overall satisfaction with the BEV purchase experience is shifting to more traditional factors, like quality and styling.

Gen 1 Wheel Bearings

Removing and installing these bearings requires the correct tools and patience.