Ambulance A & P: Steering, Suspension and Tires

6. A roaring sound that starts at about 25 mph and gets worse with speed can be a sign of a worn or damaged wheel bearing. It can be hard to localize, but if you can do that, it may prove helpful to your fleet staff. It's uncommon in newer vehicles.

7. Excessive steering play can result from a number of causes, ranging from a low tire to a misaligned or damaged steering system. Remember, the ambulance needs to start, steer, stop and stay running. Impaired steering always warrants taking the equipment out of service.

8. Vibration in the steering wheel is always abnormal. One of the things that can cause it is damage or wear to a special horizontal shock absorber called a steering damper. Let your fleet staff decide if that's the problem and if it's serious enough to bring you in.

9. Chirping or chattering noise that occurs during steering maneuvers, especially during parking, can be caused by a loose or worn drive belt or a seized power steering pump. It's never a good sign, although it may be a quick fix for your mechanic if it's just a belt.

10. A loud noise of variable quality that occurs under the conditions listed in the preceding item can result from air in the power steering lines-most often caused by a low power steering fluid level. Check your fluid level and look for leaks, then give your fleet tech a call.

11. Excessive steering effort is never acceptable, and is usually traceable to the power steering pump. The only time you can fix it is if it's related to low power steering fluid level, but even that should make you want to look for a leak somewhere.

Conclusion

The steering and suspension systems and the tires you ride on impact your safety every day, whether you're aware of them or not. Staying aware of them is just as important as your situational awareness on a scene. As a professional, you can't afford to be a passive observer or a passive driver. Make sure you come home safe at the end of every shift by remaining as alert and informed about your equipment and observant of its behavior as possible. You're worth it, don't you think?

Cap (Tony) Unrein worked as an EMT for five years with Children's Hospital of Denver and Colorado's Ambulance Service Company. He now owns EVMARS, a comprehensive fleet service company that has maintained several Denver-area EMS fleets since 1981. He has an ASE (Automotive Service Excellence) certificate and is also a certified Emergency Vehicle Technician (EVT).

Thom Dick has been involved in EMS for 40 years, 23 of them as a full-time EMT and paramedic in San Diego County. He is the quality care coordinator for Platte Valley Ambulance Service, a community-owned, hospital-based 9-1-1 provider in Brighton, CO. Thom is also a member of the EMS World editorial advisory board. E-mail boxcar_414@yahoo.com.