2007.5-2010 GMC Duramax LMM Brake Parts

How the LMM Sierra HD stops

Every 2007.5-2010 Sierra HD left the line with power four-wheel disc brakes and four-wheel antilock as standard equipment, whether it was ordered as a Work Truck, an SLE or an SLT. GM paired that with Dynamic Rear Proportioning, which balances how much braking goes to the rear axle as the load changes, and with corrosion-resistant linings. The Allison 1000 six-speed behind the LMM adds auto grade braking, downshifting on descents to take some of the heat out of the service brakes on the way down a hill. Trucks built with the Heavy-Duty Trailering Package also have the factory integrated trailer brake controller wired through the ABS, which is the cleanest way to run electric trailer brakes on one of these. Steering is power recirculating-ball, and a brake problem on one corner often announces itself through the wheel.

Where these brakes give trouble

Start at the caliper. Sticking slide pins are the usual root cause behind repeat brake complaints on these trucks, and they show up as one-sided pad wear, a wheel hub that is hot to the touch after a drive, and a brake that drags at any mileage. Left alone, that uneven heating is what takes out rotors. Owners on the forums report getting roughly 50,000 to 70,000 miles out of a set of rotors, which is an owner figure rather than a published GM interval, so a Sierra eating rotors well inside that window has a mechanical cause rather than a quality problem. Symptoms to listen for are a pulsing pedal and a shimmy through the steering wheel as speed comes down. Towing and heavier-than-stock tires add to all of it, and fade on a grade is how that usually makes itself known first.

Replace with OEM-grade, or step up

Most Sierra HDs want a like-for-like replacement. The ACDelco Gold rotors are built to the original pattern, and the black-coated hat holds up better than bare cast iron in salt and humidity. Where the truck pulls a trailer most weekends or rides on a heavier tire, the ACDelco Performance slotted rotors are the sensible step up: the slots keep the pad face swept and give you a visual read on how hard the brakes have been working. The step that matters most is not a rotor at all, though. It is doing the pins and boots with the pad job so the new parts wear flat. Flush the system while you are in there, and clean every mating surface before the rotor goes on.

What we carry

The rotor side of this page is ACDelco: Gold front and rear disc brake rotors with black-coated hats, Performance slotted front and rear rotors, and a front disc brake dust shield for the trucks that have lost theirs to rust. The brake pin and boot kit comes from Merchant Automotive. Shop consumables are Lucas Oil, including non-chlorinated brake parts cleaner, contact cleaner and synthetic DOT 3 and DOT 4 brake fluid. Wehrli Custom Fabrication builds the billet master cylinder cap and reservoir cover for the engine bay. There is more for this truck across our Duramax catalog.

Fitment notes

Order by the truck, not by the year alone. Brake parts split between the Sierra 2500HD and the Sierra 3500HD, and the 3500HD came as a single-rear-wheel or a dual-rear-wheel truck, which changes what bolts up out back. Forum rotor dimensions circulate for these trucks and we do not repeat them here because they are not GM figures, so run your VIN through the fitment checker on the product page or let us look it up. One more split to watch: the 2007 Sierra Classic is the previous body with the LBZ engine, not an LMM truck, so a 2007 build date alone is not enough to go on. The 2011 and later HD Sierras were reworked heavily, and parts do not cross that line automatically.

Frequently asked questions

Do the Work Truck, SLE and SLT Sierras use the same brakes?

The brake system itself was standard across the HD line: four-wheel disc with four-wheel ABS and Dynamic Rear Proportioning. What actually changes the parts you need is the chassis, meaning 2500HD versus 3500HD and single versus dual rear wheels, plus how the truck was equipped for trailering. Verify by VIN rather than by trim badge.

My Sierra pulls to one side under braking. Where do I start?

Check the caliper slide pins on the side that is dragging. A seized pin holds the pad on the rotor, which wears one face unevenly and makes the truck pull, and you will often find that wheel running hotter than the other after a drive. Pins, boots and a clean set of mating surfaces fix more pulls on these trucks than any other single part.

Which brake fluid should I use?

We stock synthetic DOT 3 and DOT 4 from Lucas Oil for these trucks. Use the spec called out on your reservoir cap and in the owner's manual, and do not mix types in a system. If you are not sure what is in there now, a full flush with fresh fluid is the right move anyway, and it is worth doing whenever the brakes are apart.

Is a dual-rear-wheel 3500HD different from the rest?

It can be. Rotor and caliper fitment on 2007.5-2010 HD trucks differs by 2500HD versus 3500HD and by single versus dual rear wheel, so a dually is not automatically the same parts list as a single-wheel truck. Give us the VIN and we will confirm before anything ships.

Not sure what fits? Call the shop at the number in the header, or use the fitment checker on any product page. We install everything we sell.