Diagnosing and Repairing Exhaust Leaks on the Bobcat T190 Compact Track Loader

[MikePhua]

The T190 and Its Role in Compact Construction
The Bobcat T190 is a compact track loader introduced in the early 2000s as part of Bobcat’s push into rubber-track machines for soft terrain and tight urban sites. With a rated operating capacity of 1,900 lbs and powered by a 66-horsepower Kubota V2003 diesel engine, the T190 became a staple in landscaping, utility trenching, and demolition prep. Its compact footprint, vertical lift path, and hydraulic versatility made it one of Bobcat’s best-selling models, with tens of thousands delivered globally.
The T190’s engine compartment is tightly packaged, with the exhaust manifold, turbo outlet (on turbo-equipped variants), and muffler assembly tucked behind the operator cab and above the hydraulic pump. This layout, while efficient for space, can lead to heat concentration and vibration-induced fatigue in exhaust components.
Common Symptoms of Exhaust Leaks
Exhaust leaks on the T190 typically present as:

• Loud hissing or chuffing noise during acceleration
  
• Soot buildup around manifold or muffler joints
  
• Diesel odor in the cab or near the rear of the machine
  
• Reduced engine performance or turbo lag
  
• Visible cracks or broken welds on exhaust piping
  

In one case, a landscaping crew in Ohio noticed black streaks on the rear firewall and a drop in hydraulic responsiveness. The root cause was a cracked manifold flange that allowed exhaust gases to escape and heat nearby hydraulic lines, thinning the fluid and reducing system pressure.
Exhaust System Layout and Vulnerable Points
The T190 exhaust system includes:

• Cast iron exhaust manifold bolted to the cylinder head
  
• Gasketed flange connection to the muffler inlet
  
• Steel muffler with internal baffles
  
• Tailpipe routed through the rear panel
  
• Heat shields and vibration isolators
  

Vulnerable points include:

• Manifold-to-head gasket
  
• Muffler inlet flange weld
  
• Tailpipe hanger brackets
  
• Heat shield mounting tabs
  

Vibration, thermal cycling, and corrosion are the primary causes of failure. Machines operating in wet or salty environments are especially prone to rust-induced cracking.
Inspection and Diagnostic Strategy
To locate an exhaust leak:

• Start engine and listen for abnormal sounds near the manifold
  
• Use a smoke machine or soapy water spray to detect escaping gases
  
• Inspect for soot trails or discoloration around joints
  
• Check for loose bolts or missing gaskets
  
• Use infrared thermometer to detect hot spots from escaping exhaust
  

If the leak is near the manifold, remove the heat shield and inspect the gasket and flange. If the muffler is cracked, tap lightly with a rubber mallet to detect thin or brittle areas.
Repair Techniques and Component Replacement
Depending on the location and severity:

• Replace manifold gasket with high-temp graphite or metal-reinforced type
  
• Weld muffler cracks using MIG or TIG with stainless filler rod
  
• Replace muffler if internal baffles are loose or rusted through
  
• Use anti-seize on manifold bolts during reinstallation
  
• Install new vibration isolators to reduce future stress
  

Always torque manifold bolts in sequence to avoid warping. Use OEM or equivalent parts rated for diesel exhaust temperatures (up to 1,200°F).
Preventive Measures and Long-Term Reliability
To prevent future leaks:

• Inspect exhaust system every 250 hours
  
• Clean soot and rust from joints quarterly
  
• Replace heat shields if rattling or loose
  
• Avoid prolonged idling in enclosed spaces
  
• Use high-quality diesel to reduce soot buildup
  
• Monitor engine mounts for wear that increases vibration
  

A contractor in Alberta added a flexible stainless exhaust coupling between the manifold and muffler to absorb vibration. After two years of heavy use, the system remained leak-free and quieter under load.
Conclusion
Exhaust leaks on the Bobcat T190 are more than a nuisance—they can affect performance, safety, and nearby components. With careful inspection, proper materials, and attention to vibration control, these issues can be resolved and prevented. Whether grading a backyard or trenching through clay, a sealed and healthy exhaust system ensures the T190 runs clean, quiet, and strong.