Description
This 8-pack of injector fuel return line seals fits 2004.5 - 2010 LLY, LBZ and LMM 6.6 Liter Duramax Silverado and Sierra 2500HD/3500HD trucks. Each injector has a return line fitting that's sealed with a small O-ring, and those O-rings harden and shrink with age and heat. Worn seals let fuel seep at the injectors, which can cause a diesel smell, fuel residue under the valve covers, and air getting into the return circuit.
Any time the return lines come off, for injectors, valve cover work or a return line replacement, install a fresh set of seals.
Key Features
- Set of 8: one seal for every injector
- 3.5 mm x 1.3 mm O-rings, 70 durometer
- Fits LLY, LBZ and LMM Duramax
Benefits
- Stops fuel seepage at the injector return fittings
- Keeps air out of the fuel return circuit
- Replaces all eight seals in one job
Frequently Asked Questions
How many seals do I need?
One per injector, so 8 for the full engine. This pack covers all of them.
Can I reuse my old return line seals?
We don't recommend it. The O-rings harden and take a set over time, and old seals often leak once the lines are reconnected.
When should I replace them?
Any time the injector return lines are disconnected: during injector replacement, valve cover work or a return line replacement.
Will these fit my 2001 - 2004 LB7 or 2011 - 2016 LML?
No. These are for the LLY, LBZ and LMM only. For the LML, see our LML Injector Fuel Return Line Seal 8 Pack.
Fitment
- 2004.5 - 2010 Chevrolet Silverado 2500HD / 3500HD 6.6 Liter Duramax (LLY, LBZ, LMM)
- 2004.5 - 2010 GMC Sierra 2500HD / 3500HD 6.6 Liter Duramax (LLY, LBZ, LMM)
Lines brittle or cracked? See our Fuel Injector Return Line and Clip Set with Metal Fittings, Fuel Injector Return Line and Clip Set or Return Line Clip Set. Replacing injectors?
Add new Injector Copper Washers.
What's Included
- (8) Injector fuel return line O-ring seals, 3.5 mm x 1.3 mm
Details:
- Engine Manufacturer: Duramax
- Liter: 6.6 Liter
- Engine Designation: LLY, LBZ, LMM
- Engine Years: 2004-2010
Applications:
- 2004-2010 Silverado/Sierra 2500HD/3500HD LLY/LBZ/LMM