
Dorman Products-01-07 GM 6.6L Duramax Dorman Coolant Reservoir
$84.49
- Part Number: 603-125
- Est. Ship Time: Usually Ships By Next Business Day
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This replacement engine coolant reservoir is manufactured from quality materials to withstand the stresses of underhood heat and engine vibration. It is engineered and manufactured to match the fit and function of the original part.
- Direct replacement - this engine coolant reservoir matches the fit and function of the original part
- Ideal solution - engineered for a seamless installation
- Durable construction - manufactured from quality materials to withstand underhood heat and vibration
- Trustworthy design - backed by 100 years of automotive aftermarket experience
Part number: 603-125

Its always best practice to replace rusty, missing or damaged line retainers while servicing your LB7 injectors. These stainless DHD retainers are dir..
$69.00
DHD 700-012AFT LB7 Duramax High Pressure Fuel Line KitSkip the dealer prices and replace your damaged, rusty high pressure injector lines with thi..
$399.00
Fits: 2001–2004 Chevy Silverado / GMC Sierra 2500HD & 3500HD LB7 Duramax DieselUpgrade with confidence using the DmaxStore LB7 Replaceme..
$230.75
Discontinued (Updated 5/7/2024)OEM AC Delco 04.5-10 GM 6.6L Duramax Fuel Filter Head Assembly Part number: 12642623..
$0.00
A small amount of this red sealant goes at the bottom of each injector cup to ensure proper sealing.To see the proper location of the sealant s..
$69.95
Have a higher mileage 2001-2004 GM 6.6L Duramax Diesel powered truck?
Chances are, your intercooler boots and hoses are slowly breaking down, getting..
$206.99
Discontinued (Updated 9/26/2024)Max-Flow Race Series Manifold & Up Pipe KitFits 2001-2004 Silverado/Sierra 6.6 Duramax w/Federal Emissions..
$0.00
Max-Flow High Performance Water Pump KitFits 2001-2005 Silverado/Sierra LB7/LLY DuramaxPart# MAX-HPWP-0105The Max-Flow High Performance Wa..
$409.76
Mishimoto silicone coolant hose kits are constructed from a combination of high-grade silicone and four layers of heat-resistant fibers to provide sup..
$378.95
Airflow Rating Cotton, Cleanable: Flows 47.8% better than the Stock Intake
Dry: Flows 46.7% Better than the Stock Intake
..
$349.00
Cruise the highway or hit the track with an MBRP Street Profile exhaust. It’s the perfect mix of aggressive sound when you’re into the thr..
$629.99
The PPE 114000555 MicroPure Extreme Engine Oil Filter offers 900 square inches of filtration that is 150% increase over the factory oil filter in your..
$35.99
The XDP Duramax CAT Adapter with 1R-0750 Filter, Bleeder Screw & Spacer is an easy way to upgrade the fuel filter on your 01-16 GM 6.6L Duramax. The d..
$99.95
Mahle Clevite cam bearing set for 2001-2011 6.6L Duramax Diesel.
Mahle part number: SH-1999S
Specs:Part NumbersIS777ESH-1999SH-2006
897..
$59.64
Use our improved lower valve cover bolt kit with a hex bolt instead of the allen head bolt that is sometimes hard to get a socket or wrench on. By usi..
$12.72
The Dorman 904-412 Left Side Glow Plug Harness is a direct replacement for your worn out, oil-drenched or dry rotted glow plug harness on your 2008-20..
$50.43
Dorman Engine Oil Cooler Line (Inlet, Lower)Part number: 625-164..
$57.69
This fuel water separator drain valve is designed to match the fit and function of the original valve on specified vehicles, and is engineered for dur..
$27.36
Wheel hub bolts stripped, bent or seized? These wheel hub bolts directly replace the original bolts on certain vehicle years, makes and models.&nb..
$38.11
Replacing a drive shaft doesn't have to be complicated. This complete drive shaft assembly is pre-balanced and ready to install with 100% new yokes, t..
$451.36
Fuel lines on certain Ford and International vehicles leak due to vibration from a weak bracket. This Dorman OE FIX upgrades the bracket to prevent fu..
$52.89
This replacement engine coolant thermostat housing is engineered to match the fit and durability of the stock thermostat housing on specified vehicles..
$40.09
Original equipment brake lines are highly rust prone. This Dorman OE FIX brake hydraulic line kit is made of upgraded stainless steel to resist corros..
$148.93
Fits: 2001-2003 GM Silverado/Sierra 2500HD/3500HD (See Applications) This Dorman 800-605 Transmission Line Fitting (3/8" X 5/8"..
$9.04
Fits: 2001-2004 GM 6.6L DuramaxDon't take chances with an old, questionable, or malfunctioning camshaft position sensor that can leave you strande..
$81.21
Fits: 2001-2004 GM 6.6L Duramax LB7 2500HD/3500HD | 2003-2004 GM C4500/5500 Kodiak/Topkick 6.6L Duramax LB7Purchase this Dorman 300-825 Engine Coo..
$293.48
Fits: 2001-2004 GM 6.6L Duramax LB7This Dorman Fuel Return Line Banjo Bolt (Return Pipe) is the perfect replacement component your truck needs. Ea..
$11.28
Fits: 2001-2004 GM 6.6L Duramax LB7This Dorman Glow Plug Harness Relay is perfect for what your truck needs. This part is an OE-style solution for..
$55.16
Fuel leaking from the filter housing? This direct-replacement fuel filter housing eliminates leaks from a damaged coupling to eliminate rough-start an..
$154.04
This transmission range sensor is designed to match the fit and function of the original sensor on specified vehicles, and is engineered for durabilit..
$141.38
Max-Flow Duramax Oil Cooler Upgrade KitFits 2001-2007 LB7 LLY LBZ 6.6L Duramax & 2011-2019 LML L5P 6.6L DuramaxThe Max-Flow Duramax Oil Co..
$578.25
DmaxStore Billet Coolant Block Off PlateFits 2001-2018 Silverado/Sierra 2500HD/3500HD 6.6L DuramaxPart#DMAX-CBOP-0118Replaces GM Part# 97941204The Dma..
$45.95
Max-Flow Arctic RadiatorFits 2006-2010 Chevy/GMC 2500/3500 HD LBZ / LMMPart# MAX-RAD-0610***** Trucks Equipped with Allison..
$410.99
Fits: 2006-2010 GM 6.6L Duramax LBZ/LMMWhen replacing the upper coolant hose in your vehicle, consider replacing it with the Wehrli Custom F..
$144.53
The factory plastic GM Coolant Heater Core Firewall Fitting is a common failure point on Duramax trucks and other GM vehicles. Our made in the USA, bi..
$40.74
Direct replacement coolant reservoir cap for 01-07 Duramax. Part number: 82597..
$14.04
The PPE Coolant Overflow Tank will hold up to one gallon of coolant. Hand-cut tig welded 6061 aluminum material provides more efficient cooling proper..
$269.99
Ensure your water pump is sealed properly when you add the MAHLE GS33752 Water Pump Gasket Kit to your 2001-2010 GM 6.6L Duramax. Designed a..
$22.87
CSF A/C Condenser for 01-14 DuramaxFeatures & BenefitsDirect-Fit Replacement for easy installationManufactured in ISO/TSO certified factoriesPart ..
$100.62
Direct fit replacement inlet hose tee connector for 01-14 GM 6.6L Duramax Silverado/ Sierra 3500 by Dorman.Made of quality materials, this HV..
$25.66
Direct fit replacement inlet hose tee connector for 01-14 GM 6.6L Duramax Silverado/ Sierra 3500 by Dorman.Made of quality materials, this HV..
$25.03
Fits: 2001-2016 GM 6.6L DuramaxReplaced your faulty element with the GM Block Heater Element. This heating element is a Genuine GM part that is a ..
$52.36
DHD 030-5001 Billet Rear Engine Cover Coolant Block Off PlateDHD's Billet Coolant Passage Block Plate is used to stop the problematic Duramax cool..
$60.95
A must have upgrade for your Duramax puller! This fixed fan hub will eliminate your OE viscous fan clutch and increase your intercooler efficiency. Ea..
$349.00
The Mishimoto Chevrolet Duramax high-temperature thermostats activate at a higher temperature than the OEM thermostats, making them the perfect soluti..
$99.95













































