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⚠️ FITMENT NOTICE – READ BEFORE SELECTING
The fan shroud option ONLY changes the Fill Tee Clamp mounting bracket.
All other components of the GMT800 Coolant Tank & Fill Kit are identical.
Before ordering, confirm whether your truck is running:
• Factory 34” OEM plastic fan shroud
• Aftermarket aluminum fan shroud
Selecting the incorrect option will result in an incompatible Fill Tee mounting bracket.
 
GMT800 Coolant Tank & Fill Kit (1999–2006 Silverado/Sierra)
 
Clean up your engine bay and eliminate the factory coolant mess the right way.
 
The GMT800 Coolant Tank & Fill Kit is designed specifically for 1999–2006 Silverado and Sierra trucks. This system removes the bulky factory overflow tank and eliminates the problematic Y-fill hose under the turbo that runs to the water pump.
 
Instead of relying on the factory heater hose routing, this kit converts your system to an inline upper radiator hose fill with a dedicated reservoir tank for a cleaner, more serviceable, and more reliable setup.
 
What This Kit Does
  • Deletes the factory coolant tank
  • Eliminates the Y-fill hose under the turbo
  • Removes the factory heater hose routing
  • Adds an inline fill point in the upper radiator hose
  • Cleans up cluttered engine bays (especially turbo builds)
 
Included in the Complete Kit
  • Custom coolant tank designed specifically for 99–06 GMT800 trucks
  • Brass barbed fittings
  • Designed to reuse your OEM coolant tank cap
  • 48” of 5/16 hose for inline fill to tank
  • Both new heater core hoses with molded 90° ends
    • 3/4” hose
    • 5/8” hose
  • Inline fill neck with new cap
  • Inline fill mounting bracket for aluminum fan shroud setups
  • Gates heat-shrink hose clamps for the inline fill (cleaner install than traditional worm clamps)
Complete Kit Price: $249
 
Variations Available
Just choose your configuration:
  • Tank only
  • Tank + inline fill
  • Full complete kit
Build it the way your setup requires.
 
 
Optional Upgrade: PPE Stainless Steel Heater Hose Connectors
 
For customers who want maximum durability and a premium finish, we offer an upgrade to Pacific Performance Engineering (PPE) stainless steel heater hose connectors.
 
These replace the standard brass barbed fittings with precision-machined stainless steel fittings for:
  • Increased long-term corrosion resistance
  • Improved strength under heat and pressure
  • Cleaner, more premium engine bay appearance
  • Better durability for high-performance or boosted applications
 
PPE components are known for their quality in demanding diesel and performance applications, making them an excellent upgrade for trucks that see heavy use, towing, or high-horsepower builds.
Select the "YES" on the Stainless Heater Core Fitting option when configuring your kit.
 
Why This Setup?
The factory configuration becomes cluttered and inefficient, especially on turbo applications. This system:
  • Simplifies coolant routing
  • Improves service access
  • Cleans up engine bay appearance
  • Eliminates the awkward Y-fill hose under the turbo
  • Provides a proper inline fill solution

GMT800 Coolant Tank & Fill Kit

PriceFrom $125.00
Quantity

  • The following fitment options apply only to the Fill Tee Clamp mounting bracket.
    All other components of the GMT800 Coolant Tank & Fill Kit remain the same.

    Please select the correct option based on your fan shroud setup.

    Option 1 – 34” OEM Fan Shroud

    Designed for trucks running the factory 34” OEM plastic radiator shroud.

    • Fill Tee Clamp bracket is configured specifically for the factory plastic shroud

    • Clean, secure mounting solution

    • No zip ties or unsupported mounting

    • Maintains proper fill neck positioning and service access

    Select this option if you are running the OEM plastic shroud for a 34" setup.

    Option 2 – Aftermarket Aluminum Fan Shroud

    Designed for trucks running an aluminum fan shroud, typically paired with electric fan conversions or custom cooling setups.

    • Fill Tee Clamp bracket configured for aluminum shrouds

    • Secure bolt-on mounting solution

    • Clean installation for turbo or shaved engine bay builds

    Select this option if you are running an aftermarket aluminum fan shroud.

    Important

    This selection only affects the Fill Tee Clamp mounting bracket.
    All hoses, tank components, fittings, and hardware remain identical between options.

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