Parking Brake Not Holding
Thread Starter
Member
Joined: Oct 2024
Posts: 173
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From: California
2016 E350 Sport
Parking Brake Not Holding
Happy New Year, everyone! I recently had dealer install new parking brake mechanism under third party warranty coverage. I also had rear wheels screws adjusted, but so far they don’t hold car if parked at an incline. I don’t think the brake pads are worn as car has 44K miles on the clock. Any suggestions what else could be done to get car to hold when parking brake is depressed?
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19 GLA45, 86 560SL, former: 14 E550 4Matic, 09 E350 4Matic, 83 240D manual, 78 450SLC, 81 500SLC
If the dealer just installed a new parking brake mechanism, and it doesn't work, take it back to them to fix it... It probably just needs to be adjusted.
Joined: Nov 2016
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From: Maryland
2015 SL400 (M276 Turbo), 2014 C350 Sport (M276 NA), 2004 SL500 (M113), 2004 Audi TT225 (BEA)
The parking brake pads and the operational brake pads are not the same. Still, if the car is not holding, go back to the dealer.
Joined: Nov 2016
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From: Maryland
2015 SL400 (M276 Turbo), 2014 C350 Sport (M276 NA), 2004 SL500 (M113), 2004 Audi TT225 (BEA)
FWIW, I have tried to adjust my parking brakes and they don't hold well either. Adjusting them enough to hold on an incline causes them to drag when off. Adjusting them to not drag and they don't hold well. I still apply the parking brakes when parked.
Thread Starter
Member
Joined: Oct 2024
Posts: 173
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From: California
2016 E350 Sport
If that’s the case, then what’s the point of having parking brakes in the first place. I once owned a Toyota 4Runner and I adjusted those brakes real nice by tightening a spring loaded nut under the center console. I’ll take car to dealer to check out their work when I get a chance.
Joined: Nov 2016
Posts: 7,847
Likes: 3,496
From: Maryland
2015 SL400 (M276 Turbo), 2014 C350 Sport (M276 NA), 2004 SL500 (M113), 2004 Audi TT225 (BEA)
If that’s the case, then what’s the point of having parking brakes in the first place. I once owned a Toyota 4Runner and I adjusted those brakes real nice by tightening a spring loaded nut under the center console. I’ll take car to dealer to check out their work when I get a chance.
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Joined: Apr 2019
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From: Silicon Valley
W212 MY'14 M276-3.5NA @75kMi
try this....
Happy New Year, everyone! I recently had dealer install new parking brake mechanism under third party warranty coverage. I also had rear wheels screws adjusted, but so far they don’t hold car if parked at an incline. I don’t think the brake pads are worn as car has 44K miles on the clock. Any suggestions what else could be done to get car to hold when parking brake is depressed?
It's sad when dealer techs are not allowed to fix basic systems. I remember MB dearler repair of my failed sunroof was like pulling teeth with idiots.
Rear parking brakes use independent brake shoes with an sel-adjusting ratchet mechanism.
Try setting and releasing PkgBrake 5 or 6 times to cut down on aggravations...
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From: Jakarta-Indonesia
2014 - W212.065 - E400 ( M276.820, 3 liter Turbo) RWD not Hybrid
Drum style paking brake is a bi-etch , at least for me. Good proper bite is almost never possible with zero touch ( when spinning ) due to servo action of drum brake shoe mechanism,
is more angled a movement than a straight nice disc brake type piston movement.
One thing I noticed, since drum brake ( parking brake ) is enclosed , the rusty friction surface of the inner disc brake DRUM section, hampered good parking brake bite.
Because it is enclosed, it rarely get maintained as in rust and dust control, making its working capability even less.
Just remember that drum brake/parking brake is a servo action, meaning the tire has to spin at least 180 degrees to get final good bite where the brake shoe then "expanded enough " and grip well.
Just in case user is comparing/expecting it to instant stop of disc brake or newer stand alone electric parking brake using stand alone caliper or solenoid assisted but using rear disc brake
own caliper as parking brake.
is more angled a movement than a straight nice disc brake type piston movement.
One thing I noticed, since drum brake ( parking brake ) is enclosed , the rusty friction surface of the inner disc brake DRUM section, hampered good parking brake bite.
Because it is enclosed, it rarely get maintained as in rust and dust control, making its working capability even less.
Just remember that drum brake/parking brake is a servo action, meaning the tire has to spin at least 180 degrees to get final good bite where the brake shoe then "expanded enough " and grip well.
Just in case user is comparing/expecting it to instant stop of disc brake or newer stand alone electric parking brake using stand alone caliper or solenoid assisted but using rear disc brake
own caliper as parking brake.
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Joined: Nov 2018
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From: Brazil
W212 (212.065/276.820)
I've adjusted mine using the WIS instructions and they work fine. They don't drag when released and hold the car fine on some pretty inclined roads (you do have to press the pedal hard depending on the situation). Thing to point out is that you need to make the adjustment with both rear wheel off the ground, otherwise they will bite asymmetrically when parking brake is applied.
Thread Starter
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From: California
2016 E350 Sport
I took car to dealer to inspect new parking mechanism they had recently installed. I was told it functioned as intended and the couple of inches car rolls after applying parking brakes was normal. Shop foreman took car on their shop ramp, and he put car in neutral, let it slide a few feet, then applied the parking brakes, which stopped the car a few feet down the ramp. This was his test that emergency brakes are engaging per the specs. I still believe this is a manufacturing flaw with the parking braking system. When parked on an incline or a slope with parking brakes deployed, car should not move an inch, PERIOD!
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From: Jakarta-Indonesia
2014 - W212.065 - E400 ( M276.820, 3 liter Turbo) RWD not Hybrid
I took car to dealer to inspect new parking mechanism they had recently installed. I was told it functioned as intended and the couple of inches car rolls after applying parking brakes was normal. Shop foreman took car on their shop ramp, and he put car in neutral, let it slide a few feet, then applied the parking brakes, which stopped the car a few feet down the ramp. This was his test that emergency brakes are engaging per the specs. I still believe this is a manufacturing flaw with the parking braking system. When parked on an incline or a slope with parking brakes deployed, car should not move an inch, PERIOD!
I told you already in post #9.
"Just remember that drum brake/parking brake is a servo action, meaning the tire has to spin at least 180 degrees to get final good bite where the brake shoe then "expanded enough " and grip well."
Read here : https://www.akebono-brake.com/englis...nner%20surface.
Joined: Nov 2016
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From: Maryland
2015 SL400 (M276 Turbo), 2014 C350 Sport (M276 NA), 2004 SL500 (M113), 2004 Audi TT225 (BEA)
It is called Servo Effect.
I told you already in post #9.
"Just remember that drum brake/parking brake is a servo action, meaning the tire has to spin at least 180 degrees to get final good bite where the brake shoe then "expanded enough " and grip well."
Read here : https://www.akebono-brake.com/englis...nner%20surface.
I told you already in post #9.
"Just remember that drum brake/parking brake is a servo action, meaning the tire has to spin at least 180 degrees to get final good bite where the brake shoe then "expanded enough " and grip well."
Read here : https://www.akebono-brake.com/englis...nner%20surface.
My SL uses drum-type parking brakes but they are electric and the car doesn’t budge an inch.
Last edited by JettaRed; Jan 16, 2025 at 08:03 AM.
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W212 FL
I agree, I don't like rolling the cars backwards on the hill / downhill either . I use HOLD feature to prevent it from rolling backwards . Those rolling actions could damage the trannies as well . I notice that when you press the P on the gear selector HOLD disengages but not a problem
