Parking brake adjustment, rattle
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From: Beverly Hills CA
2001 CLK430, 2000 E320 Wagon, 1992 300CE (sold), 1998 C280 (sold), 1995 C280 (sold)
Parking brake adjustment, rattle
When I drive down the street my '92 300CE is constantly rattling. I figured out that it's something in the parking brake mechanism behind the rotor. When I apply the parking brake, even a little, the rattle stops.
According to the shop manuals, you can take off the wheel and then stick a small screwdriver through the bolt hole to reach the adjustment screw that will tighten up the parking brake cable. There's only one problem: I couldn't find that screw no matter how long I looked and no matter what position the wheel was in.
Is the shop manual wrong? Or is there some secret to finding that adjustment screw?
According to the shop manuals, you can take off the wheel and then stick a small screwdriver through the bolt hole to reach the adjustment screw that will tighten up the parking brake cable. There's only one problem: I couldn't find that screw no matter how long I looked and no matter what position the wheel was in.
Is the shop manual wrong? Or is there some secret to finding that adjustment screw?
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From: Germany
'00 S320 W220, '98 A160 W168/ sold in 2005 '86 260 E W124 '90 260E W124
My guess the rattling noice comes from the rear guard of the brake disks. The parking brake pads are attached to this guard and the by the time the sheet metal they are made of starts corroding and then the guards "grind" along the hub. If its a grinding noise!!! If the function of the parking brake is okay, rattling from the pads seems not possible as I see it. But when applying the brakes and the noise stop can also be the a. m. since the brakes center the guard also.
To check take the wheel of, turn the disk and see if the noise is still there or diappears when you hold or carafully bend the guard. If this is not giving you any clou, take of the brake and the disk and see what's in side, and how the Pads of the parking brake look like.
To check take the wheel of, turn the disk and see if the noise is still there or diappears when you hold or carafully bend the guard. If this is not giving you any clou, take of the brake and the disk and see what's in side, and how the Pads of the parking brake look like.
Thread Starter
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From: Beverly Hills CA
2001 CLK430, 2000 E320 Wagon, 1992 300CE (sold), 1998 C280 (sold), 1995 C280 (sold)
The noise is definitely a rattle, not a grinding noise. My guess was that the end of the parking brake cable is rattling against some other part behind the rotor, which is why it stops as soon as I pull the cable (i.e. step on the parking brake pedal). That's why I wanted to tighten the parking brake cable to factory specs (I'm sure it has stretched in 12 years of service) and see if that stops the rattle without me having to take apart the whole brake assembly.
Does anyone know how to find that adjustment screw??
Does anyone know how to find that adjustment screw??
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Joined: Jun 2003
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From: Aridzona
'15 S550, '10 E350 P1/P2, '02 ML320
I had the same problem with my 300E. The fix was to replace the parking brakes, a fairly easy job and pretty inexpensive. There is a clip that usually fails in this system that retains the internal parking brake shoes. To get to the adjuster, you only need to take one lug bolt out and then rotate that bolt hole so that it is at 12:00. Then use a long (8") screw driver to turn the adjuster wheel until the wheel becomes slightly hard to turn by hand.
If you plan on rebuilding the parking brakes, you may want to spring for new rear rotors and pads, they wear out much slower than the fronts but if you do it now, you will not need to for quite a while. To get to the parking brake, remove the rear wheel and caliper. The brake disc should fall off in your hands, if not a little coaxing with a soft mallet should do the trick.
Have fun!
-Dennis
If you plan on rebuilding the parking brakes, you may want to spring for new rear rotors and pads, they wear out much slower than the fronts but if you do it now, you will not need to for quite a while. To get to the parking brake, remove the rear wheel and caliper. The brake disc should fall off in your hands, if not a little coaxing with a soft mallet should do the trick.
Have fun!
-Dennis
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From: Germany
'00 S320 W220, '98 A160 W168/ sold in 2005 '86 260 E W124 '90 260E W124
If you think just the cable needs to get tightend, you'll find it hidden under the main drive shaft und the car, where the main cable is "split" to into 2 cables, one per wheel. But I dont think this will help you much. I support the previous posters idea, after 12 years the parking brake needs a complete overhaul, since the pads and the cables are just getting old.
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From: Beverly Hills CA
2001 CLK430, 2000 E320 Wagon, 1992 300CE (sold), 1998 C280 (sold), 1995 C280 (sold)
Thanks for the tip. I'll take a look under the driveshaft. If I don't get success there, I'll take the brakes apart.
Tom
Tom
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my solution
Hi Tom,
My 87 300D had the same problem a few months back and a guy told me I hadnt adjusted the shoes properly.
I followed his procedure and have a great parking brake. Although my shoes are fairly worn (I have new shoes ready for installation, I just need a bit of time to install them), the brake holds well and doesnt rattle.
Slacken the handbrake cable (above the propshaft )until its fairly loose.
Take off the rear wheel, you will have more room for manoeuvring the screwdriver.
the adjustment screw (has a head with teeth like a gear or like a ratchet/pawl) is approximately 30 to 40 degrees from the top of the drum towards the front of the car. Use a torch, a mini mag is ideal!!
Tighten the pawl tooth by tooth until the shoes are pressed against the drum and it cant turn. Now loosen the pawl by about 3 or 4 clicks until the drum can rotate freely. By the way, if your shoes are too worn, the adjusting screw will be near the limit of its travel.
Do the same for the other wheel.
If you cant see how to turn the pawl, or where it is!, take off the drum and have a look at the whole assembly, note how it works, what direction to tighten etc and put on the drum again.
Now that both shoes are in the proper positions, you can start to adjust the cable under the car. This is a matter of wriggling under the car, adjusting, wriggling out, trying the brake etc. Haynes Manual says about 5 to 9 clicks. Try to turn both drums by hand when you are adjusting the parking brake to make sure that both sets of shoes are engaging.
I hope this makes sense to you, and I recommend if you have new shoes, then install them as part of this procedure.
All the best
gerard
My 87 300D had the same problem a few months back and a guy told me I hadnt adjusted the shoes properly.
I followed his procedure and have a great parking brake. Although my shoes are fairly worn (I have new shoes ready for installation, I just need a bit of time to install them), the brake holds well and doesnt rattle.
Slacken the handbrake cable (above the propshaft )until its fairly loose.
Take off the rear wheel, you will have more room for manoeuvring the screwdriver.
the adjustment screw (has a head with teeth like a gear or like a ratchet/pawl) is approximately 30 to 40 degrees from the top of the drum towards the front of the car. Use a torch, a mini mag is ideal!!
Tighten the pawl tooth by tooth until the shoes are pressed against the drum and it cant turn. Now loosen the pawl by about 3 or 4 clicks until the drum can rotate freely. By the way, if your shoes are too worn, the adjusting screw will be near the limit of its travel.
Do the same for the other wheel.
If you cant see how to turn the pawl, or where it is!, take off the drum and have a look at the whole assembly, note how it works, what direction to tighten etc and put on the drum again.
Now that both shoes are in the proper positions, you can start to adjust the cable under the car. This is a matter of wriggling under the car, adjusting, wriggling out, trying the brake etc. Haynes Manual says about 5 to 9 clicks. Try to turn both drums by hand when you are adjusting the parking brake to make sure that both sets of shoes are engaging.
I hope this makes sense to you, and I recommend if you have new shoes, then install them as part of this procedure.
All the best
gerard
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Newbie
Joined: Mar 2006
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Parking brake rattle/ Knock
Check the inside of the disc for "very slight" wear causing uneven wear across the narrowest face of the shoe from the backplate to the front edge (sloping). This allows the shoes to ride away from the backplate against the retaining springs and then snap back causing the rattle /knock. Ramblings from a mad MB driver.
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Joined: Dec 2002
Posts: 882
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From: Sherman Oaks
2004 C240, 2015 GL350 Bluetec
one of the parking brake shoe retaining springs is probably broken.
Simple fix cheap part.
Remove rear wheel, remove caliper, and remove the disc, you will see the parking brake mechanism. simply find the broken spring and replace it.
Happened on my car whent he rear lugs were too long they snapped the springs. I had this annoying, and extremely embarrising squeel when driving.
The culprit was like a few dollars spring.
Simple fix cheap part.
Remove rear wheel, remove caliper, and remove the disc, you will see the parking brake mechanism. simply find the broken spring and replace it.
Happened on my car whent he rear lugs were too long they snapped the springs. I had this annoying, and extremely embarrising squeel when driving.
The culprit was like a few dollars spring.
Newbie
Joined: Dec 2006
Posts: 1
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From: Andover, ma.
1987 mercedes 300e
I am trying to repair the parking brake on a 9187 mercedes 300e and am having a hard time disconnecting the eyelet at the end of each cable from the v shaped notches on the flat platelocated by the drive shaft. I was able to run the adjuster bolt all the way out releaving the tension on the cables. I still don't seem to have enough slack.
The piece at the end of each cable that holds the bottom of each break pad is somewhat corroded and will not operate. Any suggestions on how to clean?
How do I completely remove each cable in case I have to replace.
Would appreciate wny suggestions you might have.
Thanks,
Richard Jackson
The piece at the end of each cable that holds the bottom of each break pad is somewhat corroded and will not operate. Any suggestions on how to clean?
How do I completely remove each cable in case I have to replace.
Would appreciate wny suggestions you might have.
Thanks,
Richard Jackson
Thread Starter
Almost a Member!
Joined: May 2003
Posts: 47
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From: Beverly Hills CA
2001 CLK430, 2000 E320 Wagon, 1992 300CE (sold), 1998 C280 (sold), 1995 C280 (sold)
Richard,
I didn't have to take the brake apart to fix my rattle. I just had to turn an adjustment screw from the outside. Since I never took the brake apart I'm afraid I can't be any help to you.
Good luck with the repair.
Tom
I didn't have to take the brake apart to fix my rattle. I just had to turn an adjustment screw from the outside. Since I never took the brake apart I'm afraid I can't be any help to you.
Good luck with the repair.
Tom
