Parts Catalog Accessories Catalog How To Articles Tech Forums
Call Pelican Parts at 888-280-7799
Shopping Cart Cart | Project List | Order Status | Help

Go Back   PeachParts Mercedes-Benz Forum > Mercedes-Benz Tech Information and Support > Tech Help

LinkBack Thread Tools Display Modes
Old 12-10-2010, 02:23 PM
Registered User
Join Date: Apr 2006
Location: Mountain View CA.
Posts: 74
How Soon After Brake Pad Warning Light Do I Need to Change Pads?


I replaced all four rotors and pads on my 1991 420SEL 30,000 miles ago. The brake pad warning light came on yesterday. How soon do I need to replace the pads? Can I drive for a few more weeks? Also is 30,000 miles normal for pad replacement?

Thanks in advance

1988 420 SEL
1991 420 SEL with 560 motor
1993 Miata
Reply With Quote
Old 12-10-2010, 02:36 PM
Stretch's Avatar a shield of steel
Join Date: Sep 2009
Location: Somewhere in the Netherlands
Posts: 14,461
The safest way is to check the thickness of the pads - sorry I don't know the limit for your car.
1992 W201 190E 1.8 171,000 km - Daily driver
1981 W123 300D ~ 100,000 miles / 160,000 km - project car stripped to the bone
1965 Land Rover Series 2a Station Wagon CIS recovery therapy!
1961 Volvo PV544 Bare metal rat rod-ish thing

I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior

Don't leave that there - I'll take it to bits!
Reply With Quote
Old 12-10-2010, 02:43 PM
pawoSD's Avatar
Join Date: Oct 2004
Location: Grand Rapids, MI
Posts: 15,216
30,000 miles sounds about right for pads on a LWB W126....I usually only get around that on mine. Once the warning light is lit solid you don't have all that long....maybe 1500 miles of average driving. I'd still physically check them.
-diesel is not just a fuel, its a way of life-
'15 GLK250 Bluetec 86k - mine - (OC-91,200)
'17 Metris(VITO!) - 15k - wifes (OC-17k)
'01 E320 Wagon - 159k - mine (OC-160,000)
'01 E320 - 179k - dad's (OC-182,500)
'07 E350 Wagon - 133k - dad's (OC-132,500)
'01 SL500 - 51k - dad's (OC-52,000)
'16 E400 4matic Sedan - 63k - Brothers (OC-64,000)
Reply With Quote
Old 12-10-2010, 04:00 PM
Registered User
Join Date: Apr 2006
Location: Mountain View CA.
Posts: 74
Great. Thanks for your response. The sensor is not on solid yet. I just need a few weeks and a few hundred more miles.
1988 420 SEL
1991 420 SEL with 560 motor
1993 Miata
Reply With Quote
Old 12-10-2010, 04:05 PM
Registered User
Join Date: Aug 2002
Location: Southeastern PA
Posts: 3,035
Dave, it's difficult to say how long or how many miles the brake pads will last before damaging the rotors without knowing your driving habits. It would seem that you do a considerable amount of highway driving ... based on that I would say up to 2,000 miles. Obviously as soon as you replace the brake pads the cycle starts on the new brake pads so it's a good idea to maxmize the wear on the existing brake pads. However, if you're a procrastinator it may be wise to change the brake pads sooner rather than later.
Fred Hoelzle
Reply With Quote
Old 12-10-2010, 08:28 PM
Registered User
Join Date: Jul 2008
Posts: 1,236
The big question is what shape are the rotors in? If they are in tolerance for thickness and runout, don't risk ruining them by going metal on metal.

If they are already warped or too thin, then you risk less my pushing the envelope.

1990 300SE "Corinne"- 145k daily driver - street modified differential - PARTING OUT OR SELLING SOON - PORTLAND OR. AREA - PM ME FOR DETAILS
1988 560SEL "Gunther"- 190K passes anything except a gas station
1997 S420 - 265k just bought it with a rebuilt trans. Lovely condition
Reply With Quote
Old 12-10-2010, 09:30 PM
tobybul's Avatar
Registered User
Join Date: Sep 2005
Location: West Michigan
Posts: 2,076
Unfortunately, the brake warning sensor indicator does not always mean worn pads. It could be that the sensor itself is not on properly like what happens to my 123. Although I have ot had it happen for a long time.

But that does not mean you should ignore it. I would at least chk the thickness of the pads.
the sooner you start... the sooner you'll get done If it ain't broke, don't fix it.. Its always simpler to tell the truth...
2007 Honda Accord EX
2007 Honda Accord SE V6
96 C220
97 Explorer - Found Another Home
2000 Honda Accord V6 - Found Another Home
85 300D - Found Another Home
84 300D - Found Another Home
80 300TD - Found Another Home
Previous cars:
96 Caravan
87 Camry
84 Cressida
82 Vanagon
80 Fiesta
78 Nova
Ford Cortina
Opel Kadet
68 Kombi
Reply With Quote
Old 12-12-2010, 06:50 PM
I told you so!
Join Date: Jun 2002
Location: Motor City, MI
Posts: 2,833
New pads are 11 mm thick.
Sensors are triggered at 2.5 mm pad thickness.
Discard thickness is 2 mm.
Reply With Quote
Old 12-13-2010, 05:33 PM
mak mak is offline
Join Date: Jul 2006
Location: Westfeld .
Posts: 687
Originally Posted by Kestas View Post
New pads are 11 mm thick.
Sensors are triggered at 2.5 mm pad thickness.
Discard thickness is 2 mm.
All the relevant and required information.

Reply With Quote


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On

All times are GMT -4. The time now is 03:18 PM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2020, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2018 Pelican Parts, LLC - Posts may be archived for display on the Peach Parts or Pelican Parts Website -    DMCA Registered Agent Contact Page