Mercedes-Benz Forum banner

1 - 7 of 7 Posts

Registered
W220 S350/S500 2004
Joined
385 Posts
Discussion Starter #1
On 2004 S500:
Followed the parking brake adjustment procedure (https://w220.ee/Parking_brake#Adjusting_parking_brake) but the parking brake is still too weak.

The adjustment on rear shoes is almost touching the shoe and the slack adjuster is on the tightest position (see below), but the parking brake is still to weak and when depressed the brake hoses are so slack that they even fall off from the slack adjuster (see below).
It seems that if only the parking brake hoses going to the wheels would be a bit shorter then parking brake would be strong enough. Any ideas? Is the only possible cause too worn brake shoes?

2610794
2610795
 

W220 Moderator
S500 W220 SLK320 R170 C200 CDI W203 Peugeot Expert Van
Joined
5,852 Posts
Hi,

More likely Seized Cables or Seized Expanders.

I have covered this many times in the past, but likely that is all lost since the greatest Forum Software Upgrade in the World ........... NOT !! :(

Correct Procedure will be FIRST let off and lock the Auto Adjuster on Cable to it's slackest setting, then strip off Discs and inspect everything making sure the Shoe Expanders and internal Adjusters are free, also make certain that the Cables are totally free and at the end of their "Off" Travel.

Replace any necessary parts, double check that the Cable Auto adjuster has not come un clipped from it's slackest position, then adjust the Shoes with Disc On, using the Internal Adjusters through the Wheel Bolt Hole until Shoes are rubbing slightly, now pop the clip on the Cable Auto Adjuster and it should spring around to tension the Cable ............. Job Done.

HTH,
 

Registered
2005 S600
Joined
479 Posts
Agree with all that Dave said as far as adjustment...however...

If I were to go through the trouble of taking off the discs, then new shoes and retaining hardware would be going back on there. Parking brake shoes and hardware aren't expensive, $40 for all ATE parts from FCP Euro.

Edit: I see that you're in Estonia...I don't know what your parts cost is going to be with VAT, etc... so, perhaps research that, but even if it were more, I would still go with new shoes and hardware. Contaminated and/or glazed shoes are common if the car had work done, a leak, or a previous owner drove with the brake on.

Be certain that the inside of the rotors are cleaned up - not contaminated with grease/dirt. Wire wheel on a drill works well.

After the installation and adjustment, I stop the car once from 20 MPH using just the parking brake to seat/bed the shoes.

 

Registered
2006 S600
Joined
234 Posts
Handbrakes are a bit of a pain.
There are two separate and different adjustments:
The adjustment inside the drum accommodates shoe wear. Do this first. Get a head torch.
The auto adjustment pictured accommodates cable stretch. Do this last.
Both mechanisms are prone to corrosion and seizing, so clean 'em up.
Between you and me, what I also did was unhook the cables pictured and add a big nut to the end. ;-)

Nick
 

Registered
2006 S600
Joined
234 Posts
Incidentally, I doubt if many people realise this, but the clicking of the parking brake pedal isn't a ratchet - it's just a clicking sound made by a clicker. The pedal is actually friction locked by a big coil spring.

I removed the clicker on one of my cars, and the parking brake was silent, but worked just the same. I wouldn't recommend it, it's a painful job.

Nick
 

Registered
W220 S350/S500 2004
Joined
385 Posts
Discussion Starter #7
You were correct Dave! The expansion locks on both sides were completely seized (see below). Broke them free and greased.
While I was at it, followed the Astro's recommendation and installed new ATE brake shoes.
Now the slack adjuster is in the medium position and when parking brake pedal is pressed at 30km/h, the rear wheels block immediately.
Let's see how long it will take until expansion locks will become seized again.
2611296
2611297
 
1 - 7 of 7 Posts
Top