GM Truck SUV Engine Coolant Expansion | Oil Catch Can Air Oil Separator Combo Tank | Fits 99-07 GMT800/820/830 Trucks & SUVs

Straightboost® Coolant Expansion Reservoir & Oil Catch Can (Air Oil Separator) Combo Tank

Fits 1999–2007 GM Truck and SUV (Silverado, Sierra, Tahoe, Suburban, Avalanche)

One of the most complete and well-engineered coolant expansion and oil catch can combo tanks available on the market, designed specifically for high-performance GM truck & SUV builds.

At Straightboost® Performance, we are committed to developing purpose-built components for the automotive performance community. We are proud to offer this custom coolant expansion and oil catch can combo tank, engineered for 1999–2007 Chevrolet Silverado and GM trucks that require improved durability, clearance, and performance over the factory plastic tank.

Whether you’re replacing the OEM tank for aesthetics, reliability, or turbo clearance, this all-aluminum solution delivers increased longevity and superior heat resistance compared to the factory unit.

Vehicle Fitment

• Designed for 1999–2007 GM Truck and SUV (Silverado, Sierra, Tahoe, Suburban, Avalanche)

• Optimized to allow turbo installations without clearance or overheating issues

• May fit other GM vehicles using the same factory-style plastic expansion tank
  (Please contact us if you are unsure about compatibility)

Oil Catch Can Performance

This system utilizes our proven multi-level internal baffle design, engineered to remove maximum oil vapor while maintaining unrestricted airflow. The result is effective oil separation without introducing crankcase restriction—ideal for both street and performance applications.

Customization

• Fittings can be changed or relocated upon request

• Contact us prior to purchase for custom configurations

Specifications

• Brand: Straightboost®

• Material: Aluminum

• Finish: Natural Aluminum

• Construction: Fully TIG welded

Features

• Coolant level sight tube

• Billet aluminum radiator cap (Machined Aluminum)

  • 16 PSI (OEM replacement)

  • 28 PSI / 36 PSI (high-performance applications)

• Billet aluminum coolant inlet/outlet barb ports

• (2) -10AN breather ports

• Multi-level internal oil baffle system

• Breather filter screen

• Laser-cut aluminum retaining plate

• 6AN ORB drain port with billet aluminum drain valve

• Integrated dipstick for oil catch can level inspection

Capacity

• Coolant Side: 3.75 qt (3.57 L)

• Oil Catch Can Side: 1.8 qt (1.7 L)

Dimensions (See Reference Photo)

• Length: 10″ (254 mm)

• Width: 6.5″ (165 mm)

• Height (tall side): 8″ (203 mm)

• Height (short side): 5″ (127 mm)

Important Notes

• Does NOT work with factory airbox or filter

• No coolant level sensor port

• For off-road or race use only

• Light surface scratches may be present due to the manufacturing process

• Made to order — production time: 5–10 business days

Proudly Made in the USA