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Mercedes GL450 GL320 GL350 GL550 Brake Repleacement

In this article I will show you how to replace the front and the rear brake rotors and pads on a Mercedes GL450.  This article is relevant to 2007-2012 GL450 as well as GL320, GL350 and GL550.  As for the parts, I used Zimmerman coated rotors, Jurid front pads and Textar rear pads.  For some reason Mercedes used Jurid pads as OEM in the front and Textar in the back.

Tools needed:

Torque wrench.

Torque angle wrench.

C-Clamp.

Breaker bar.

Wire brush.

Sockets: H9, H7, T30, E10, 21mm, 18mm.

Mercedes GL450 tools needed for brake replacement.

FRONT

1.  Start out by jacking up the SUV, removing the wheels and safely supporting the SUV on the jack stands.

Mercedes GL450 up on the jack stands

2.  Unbolt the brake wear sensor connector from the caliper and disconnect the wear sensor.

Mercedes GL450 removing the brake wear sensor.

3.  Remove the brake caliper anti-rattle clip.

Mercedes GL450 Brake Caliper Anti-Rattle clip removal.

4.  Unbolt the two caliper guide pins and remove them from the bushing.  You will need a 9mm hex bit, it is not very common size so check your tool box to see if you have one.

Mercedes GL450 Brake Caliper Guide Pin Removal.

5.  A worn out rotor will have a lip that will prevent the caliper from being removed.  Use a C-Clam to compress the caliper pistons.  Check your brake fluid level after compressing each caliper to make sure it doesn't overflow.

Mercedes GL450 compressing the brake caliper piston.

6.  To avoid damaging the brake hose, hang the caliper.

Mercedes GL450 Brake caliper hanging on a wire to prevent the damage to the brake hose.

7.  Remove the caliper bracket.  You will probably need a breaker bar to remove the two bolts, the bolts are very tight.

Mercedes Gl450 Removing the caliper bracket bolts.

8.  Use a T30 bit to remove the brake rotor set screw.  Remove and discard the brake rotor.  If the rotor is rusted on to the hub, you will  need to whack it with a hammer from the back a few times.

Mercedes GL450 removing the brake rotor set screw.

9.  Once the rotor is removed, use  a wire brush to clean the rust off the hub.

Mercedes GL450 cleaning the wheel hub with a wire brush.

10.  Lubricate the center of the hub with some anti-seize.

Mercedes GL450 lubricating the wheel hub.

11.  Install the new rotor and lubricate the set screw with some anti-seize.

12.  Clean the caliper bracket with a wire brush and lubricate all of the points that come in contact with the brake pad.

Mercedes GL450 lubricating the caliper bracket.

13.  Caliper bracket bolts are one time use.  Install the caliper bracket and torque the bolts in two steps.  Step 1 to 80Nm or 59ft/lbs.  Step2, turn the bolts 45-degrees.

Mercedes GL450 bolting up the caliper bracket.

Mercedes GL450 bolting up the caliper bracket.

14.  Clean the brake caliper with a wire brush.  Be careful not to damage the caliper dust boots.

Mercedes GL450 cleaning the caliper.

15.  Clean the caliper guide pins, do not lubricate.

16.  Lubricate all of the parts of the caliper with anti-seize that come in contact with the brake pads.

Mercedes GL450 lubricating the caliper.

17.  Install the caliper and tighten down the caliper guide pins.  You may need to press in the caliper pistons a little more.  

Mercedes GL450 Compressing the caliper piston.

18. Install the wear sensor into the inner brake pad.  Connect the brake wear sensor and bolt up the wear sensor connector to the caliper.

Mercedes GL450 Installing the brake pad wear sensor.

19.  Install the anti-rattle clip.

REAR

1.  Remove the anti-rattle clip

Mercedes GL450 Removing the anti-rattle clip

2.  Disconnect the brake pad wear sensor and unbolt the wear sensor connector from the caliper.

Mercedes GL450 removing the brake pad wear sensor.

3.  Use a C-Clamp to compress the caliper piston.

Mercedes GL450 Compressing the brake caliper piston

4.  Unbolt the caliper guide pins, you will need a 7mm Hex bit.

Mercedes GL450 Removing the brake caliper.

5.  Remove the caliper and lay it on on of the control arm so the brake fluid hose doesn't get damaged.

Mercedes GL450 brake caliper removed.

6.  Unbolt the caliper bracket.

Mercedes GL450 Unbolting the caliper bracket.

7.  Remove the brake rotor set screw, remove the rotor and discard.  Be sure your parking brake is not set or the rotor will not come off.

Mercedes GL450 removing the brake rotor set screw.

8.  With the rotor removed, use a wire brush to clean the wheel hub.  Lubricate the middle of the wheel hub with some anti-seize.

Mercedes GL450 cleaning the wheel hub.

9.  Install the new rotor and use anti-seize on the rotor set screw.  Don't forget to reuse the rubber plug from the old rotor to plug up the hole used for the parking brake adjustment.

Mercedes GL450 installing the brake rotor screw.

10.  Clean the caliper bracket with a wire brush and lubricate all of the points that touch the pads with some anti-seize.

Mercedes GL450 cleaning the caliper bracket

11.  Install the caliper bracket.  Use new bolts.  Torque should be applied in two steps.  Step 1 is 60Nm, Step 2 is 45-degrees.

12.  Clean the caliper with a wire brush.  Be careful not to damage the piston rubber boots.  Lubricate all points that come in contact with the brake pads.

Mercedes GL450 lubricating the brake caliper

13.  Install the brake pads into the caliper and bolt the caliper up to the bracket.  Don't forget to clean the guide pins.

Mercedes GL450 installing the brake caliper.

14.  Install the brake wear sensor and bolt up the wear sensor connector to the caliper.

Mercedes GL450 Installing the brake pad sensor.

15.  Reinstall the anti-rattle clip.

16.  Bleed the brakes.

Mercedes GL450 Bleeding the brakes.

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