Re: [MBZ] 1989 Mercedes 300SE Brake weirdness
Now that you know how to test, assuming you'd be willing to spend time at a pick-n-pull, here are the other models that use the same sensors on the front axle, mined from the free on-line EPC (http://epc.startekinfo.com/epc/home.jsp). I assumed that a 1989 300SE is a 126.024, someone correct me if wrong. The part looks like it has been revised four times - I wonder if there is a recall on this? Worth asking your dealer's service manager perhaps? Part number is 126 540 25 17 for front left, 126 540 26 17 for front right. 300SEL 380SE 420SEL 500SEL 560SEL 560SEC 300SD 300SDL 350SD 350SDL Plus all 123s in Euro trim that have ABS. -Max -Original Message- From: mercedes-boun...@okiebenz.com [mailto:mercedes-boun...@okiebenz.com] On Behalf Of Jim Cathey Sent: Thursday, April 22, 2010 10:36 PM To: Mercedes Discussion List Subject: Re: [MBZ] 1989 Mercedes 300SE Brake weirdness Is there a way to test the pickups with a multimeter? Connect multimeter on AC voltage in parallel to the (connected) pickup, and look for a smoothly rising voltage (and frequency) signal as you speed up. Needs to be equal on all three sensors, no jitters. -- Jim ___ http://www.okiebenz.com For new and used parts go to www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com ___ http://www.okiebenz.com For new and used parts go to www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] 1989 Mercedes 300SE Brake weirdness
ABS is good on wet/icy/dry pavement, and bad on soft surfaces. One soft surface that is perhaps appropriate for ABS is your lawn! (Though an inadvertent peel-out is far more likely than a skid.) -- Jim ___ http://www.okiebenz.com For new and used parts go to www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] 1989 Mercedes 300SE Brake weirdness
My driveway is all dirt, I notice the ABS on the vehicles that have it engages occasionally when stopping on the driveway or other areas I drive on, in particular when it is wet after a rain. I am never going very fast, but I find it somewhat interesting that it concerns itself with that situation. Only a few times have I had ABS engage when braking on a regular paved road, usually when it is wet or there is some gravel or sand or something. --R On 4/23/2010 9:53 AM, Jim Cathey wrote: ABS is good on wet/icy/dry pavement, and bad on soft surfaces. One soft surface that is perhaps appropriate for ABS is your lawn! (Though an inadvertent peel-out is far more likely than a skid.) -- Jim ___ http://www.okiebenz.com For new and used parts go to www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com ___ http://www.okiebenz.com For new and used parts go to www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] 1989 Mercedes 300SE Brake weirdness
It affects the nut holding onto the steering wheel. Hendrik who is a big nut From: Dillon, Meade M CIV SPAWARSYSCEN-ATLANTIC, 53310 meade.m.dil...@navy.mil To: Mercedes Discussion List mercedes@okiebenz.com Sent: Fri, 23 April, 2010 2:12:43 AM Subject: Re: [MBZ] 1989 Mercedes 300SE Brake weirdness How does ABS do more harm than good? Not arguing, trying to learn the limitations of a system I have on three cars. -Max -Original Message- From: mercedes-boun...@okiebenz.com [mailto:mercedes-boun...@okiebenz.com] On Behalf Of Jim Cathey Sent: Thursday, April 22, 2010 10:12 AM To: Mercedes Discussion List Subject: Re: [MBZ] 1989 Mercedes 300SE Brake weirdness I really don't understand why you don't just fix it. It's a safety system with proven worth - why not repair it? Except on loose surfaces, where ABS can actually do more harm than good. (Such as fresh snow or slush, or gravel, or [like the road immediately outside our driveway] a steep gravel road often covered in fresh snow or slush!) ABS is nice enough, but once it starts acting up so that you can no longer trust the brakes, and the easy/obvious repair attempts don't work, then I say that I'd rather disable it than mistrust the brakes, or dump thousands for new ABS parts into a car that cost less than that in the first place. -- Jim ___ http://www.okiebenz.com For new and used parts go to www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com ___ http://www.okiebenz.com For new and used parts go to www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com ___ http://www.okiebenz.com For new and used parts go to www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] 1989 Mercedes 300SE Brake weirdness
I really don't understand why you don't just fix it. It's a safety system with proven worth - why not repair it? Think your insurance company would like to have this thread exchange, especially post-collision when they are trying to decide to cover a claim or not? -Max -Original Message- From: mercedes-boun...@okiebenz.com [mailto:mercedes-boun...@okiebenz.com] On Behalf Of Kathmandu Sent: Wednesday, April 21, 2010 19:49 To: mercedes@okiebenz.com Subject: Re: [MBZ] 1989 Mercedes 300SE Brake weirdness It's centered between the firewalls on the 126, has a great big 35-pin two-row connector. Ok, found and unplugged it. It disabled the ABS just fine but it still caused the ABS light to go off just like anything else I unplugged which again makes sense as you would want an indication of a failure if any of these parts failed. I experimented with a prying screwdriver and found the gage cluster is simply wedged in the dash. I removed the light bulb from the ABS indicator, pulled a relay out and all was right with the world after that. ___ http://www.okiebenz.com For new and used parts go to www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com -- next part -- A non-text attachment was scrubbed... Name: smime.p7s Type: application/x-pkcs7-signature Size: 4941 bytes Desc: not available URL: http://okiebenz.com/pipermail/mercedes_okiebenz.com/attachments/20100422/6e198ef2/attachment.bin ___ http://www.okiebenz.com For new and used parts go to www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] 1989 Mercedes 300SE Brake weirdness
Maybe I'm using the term wrong, what I meant is the front bumper/lights/fenders/grill/hood as well as all the stuff behind the grill and in front of the engine. -Max -Original Message- From: mercedes-boun...@okiebenz.com [mailto:mercedes-boun...@okiebenz.com] On Behalf Of Alex Chamberlain Sent: Wednesday, April 21, 2010 22:20 To: Mercedes Discussion List Subject: Re: [MBZ] 1989 Mercedes 300SE Brake weirdness On Tue, Apr 20, 2010 at 7:25 AM, Dillon, Meade M CIV SPAWARSYSCEN-ATLANTIC, 53310 meade.m.dil...@navy.mil wrote: I had full steering control due to the ABS which saved my bacon and the front clip of my '87 wagon. Not that I don't know what you mean, but that's an odd term to use of a unitbody car, it strikes me. How long has it been since cars had a clip as a separate, replaceable section of the body, like the fenders? A guy on Craigslist here has been prominently advertising an '80s RWD Buick with a Euro clip, which sounds like something you give a French poodle. Alex ___ http://www.okiebenz.com For new and used parts go to www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com -- next part -- A non-text attachment was scrubbed... Name: smime.p7s Type: application/x-pkcs7-signature Size: 4941 bytes Desc: not available URL: http://okiebenz.com/pipermail/mercedes_okiebenz.com/attachments/20100422/558c5d3a/attachment.bin ___ http://www.okiebenz.com For new and used parts go to www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] 1989 Mercedes 300SE Brake weirdness
I really don't understand why you don't just fix it. It's a safety system with proven worth - why not repair it? Except on loose surfaces, where ABS can actually do more harm than good. (Such as fresh snow or slush, or gravel, or [like the road immediately outside our driveway] a steep gravel road often covered in fresh snow or slush!) ABS is nice enough, but once it starts acting up so that you can no longer trust the brakes, and the easy/obvious repair attempts don't work, then I say that I'd rather disable it than mistrust the brakes, or dump thousands for new ABS parts into a car that cost less than that in the first place. -- Jim ___ http://www.okiebenz.com For new and used parts go to www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] 1989 Mercedes 300SE Brake weirdness
On 4/22/2010 9:11 AM, Jim Cathey wrote: I really don't understand why you don't just fix it. It's a safety system with proven worth - why not repair it? Except on loose surfaces, where ABS can actually do more harm than good. (Such as fresh snow or slush, or gravel, or [like the road immediately outside our driveway] a steep gravel road often covered in fresh snow or slush!) ABS is nice enough, but once it starts acting up so that you can no longer trust the brakes, and the easy/obvious repair attempts don't work, then I say that I'd rather disable it than mistrust the brakes, or dump thousands for new ABS parts into a car that cost less than that in the first place. -- Jim So, how would you best disable it? We think my wife's Avalon suffered a failure of the ABS system that left her without brakes. One would think it needs to go beyond just pulling a fuse or something like that to the point of removing the plumbing and re-connecting the system without the ABS pump setup. Randy ___ http://www.okiebenz.com For new and used parts go to www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] 1989 Mercedes 300SE Brake weirdness
How does ABS do more harm than good? Not arguing, trying to learn the limitations of a system I have on three cars. -Max -Original Message- From: mercedes-boun...@okiebenz.com [mailto:mercedes-boun...@okiebenz.com] On Behalf Of Jim Cathey Sent: Thursday, April 22, 2010 10:12 AM To: Mercedes Discussion List Subject: Re: [MBZ] 1989 Mercedes 300SE Brake weirdness I really don't understand why you don't just fix it. It's a safety system with proven worth - why not repair it? Except on loose surfaces, where ABS can actually do more harm than good. (Such as fresh snow or slush, or gravel, or [like the road immediately outside our driveway] a steep gravel road often covered in fresh snow or slush!) ABS is nice enough, but once it starts acting up so that you can no longer trust the brakes, and the easy/obvious repair attempts don't work, then I say that I'd rather disable it than mistrust the brakes, or dump thousands for new ABS parts into a car that cost less than that in the first place. -- Jim ___ http://www.okiebenz.com For new and used parts go to www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com ___ http://www.okiebenz.com For new and used parts go to www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] 1989 Mercedes 300SE Brake weirdness
I really don't understand why you don't just fix it. It's a safety system with proven worth - why not repair it? Think your insurance company would like to have this thread exchange, especially post-collision when they are trying to decide to cover a claim or not? Tell me how to fix it. Please. The only help I have received is really how to disconnect it and that's it. Is there a way to test the pickups with a multimeter? Being unemployed at the moment I can't afford the $1500 the local Mercedes dealership will charge, I can't afford $250 a piece for sensors I may not need or $300 for a brain box that may have nothing wrong with it. And quite frankly, every time I've driven a car/truck with antilock brakes that have kicked in, it has resulted in unexpected reactions that caused more dangerous situations that it has ever solved so I am not in a huge hurry to fix it. It's a $2000 car at best with 170,000 miles on it. ___ http://www.okiebenz.com For new and used parts go to www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] 1989 Mercedes 300SE Brake weirdness
So, how would you best disable it? We think my wife's Avalon suffered a We're talking about unplugging the brain box, which leaves all the plumbing parts in neutral. failure of the ABS system that left her without brakes. One would think it needs to go beyond just pulling a fuse or something like that to the point of removing the plumbing and re-connecting the system without the ABS pump setup. If you had a plumbing failure inside the servo mechanism, then re-plumbing the system would be required to repair it. That kind of failure is rare on these MB's. (I've never heard of one.) -- Jim ___ http://www.okiebenz.com For new and used parts go to www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] 1989 Mercedes 300SE Brake weirdness
How does ABS do more harm than good? Not arguing, trying to learn the limitations of a system I have on three cars. On soft surfaces, like dirt, sand, gravel, snow, or slush, braking effect goes _way_ up once you can plow up a ridge in front of your locked tire. ABS will prevent this from happening. ABS is good on wet/icy/dry pavement, and bad on soft surfaces. -- Jim ___ http://www.okiebenz.com For new and used parts go to www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] 1989 Mercedes 300SE Brake weirdness
Is there a way to test the pickups with a multimeter? Connect multimeter on AC voltage in parallel to the (connected) pickup, and look for a smoothly rising voltage (and frequency) signal as you speed up. Needs to be equal on all three sensors, no jitters. -- Jim ___ http://www.okiebenz.com For new and used parts go to www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] 1989 Mercedes 300SE Brake weirdness
Sounds like dirty sensors in the front wheels. Pull them out, clean sensor ends and tone wheel (spray brake cleaner liberally, check for rocks and junk stuck in the tone wheels). If that doesn't fix, then maybe you have a flaky sensor/cable (but that usually will make the ABS light come on and stop the weirdness). You can test for a low voltage AC signal from each sensor when the wheel is turning. ABS module works by comparing the frequency (speed) of the front tires and the rear axle and decides how much brake pressure the front wheels and the rear axle will get. When the system is working it is a beautiful thing indeed. A few weeks ago, while driving at 80+ on I-95 north in heavy traffic, suddenly everyone slammed on their brakes due to a slow moving vehicle (~35 mph) in the right lane. I was following too close and my reactions were too slow, and despite standing on the brake pedal has hard as I could, I was going to collide with the car in front of me if I didn't turn left or right. He finally broke left to avoid the car in front of him, so I steered right, still under full braking. Missed him by a couple feet, and the overlap of my front end to his rear end was about six feet, but I had full steering control due to the ABS which saved my bacon and the front clip of my '87 wagon. In other words, repair it now rather than find out you need it but don't have it later. -Max -Original Message- From: mercedes-boun...@okiebenz.com [mailto:mercedes-boun...@okiebenz.com] On Behalf Of Hendrik Riessen Sent: Tuesday, April 20, 2010 9:07 AM To: Mercedes Discussion List Subject: Re: [MBZ] 1989 Mercedes 300SE Brake weirdness Pull the ABS relay (under the black cover that says ABS) and see if the problem is still happening. The ABS system will give a short test pulse when you first take off and Kaleb is right, dirty or inoperative sensors will play havoc but the symptoms I had was that there where a few test pulses and then after a few hundred meters the ABS light would come on. Not sure about the 126 chassis but I know that 201 sensors will fit in a 124. Hendrik whose 124 has 201 ABS sensors out the front From: Kaleb C. Striplin ka...@striplin.net To: Mercedes Discussion List mercedes@okiebenz.com Sent: Tue, 20 April, 2010 10:04:21 PM Subject: Re: [MBZ] 1989 Mercedes 300SE Brake weirdness that is the abs operating. If you were on dry pavement and not slipping, then the wheel sensors are probably dirty. Kathmandu wrote: Hello folks, I have some weird happinins' going on with my brakes on my 300SE. It has ABS on it and I have little experience with it in general as I have avoided the things purposely on all cars I've had until the Mercedes. I am reasonable competent in the mechanics area and I have worked on brakes before but this is new to me. Yesterday when driving home from Wally World the brakes started an odd pulsing when coming to a moderate stop. It is usually just before the car comes to a full stop, maybe a second or so. The pedal pulses up (not a softening of the pedal like a master cylinder problem) and the front brakes make a sort of twang sound like a spring vibrating. It doesn't affect the stopping ability, doesn't grab, pull to a side or anything and it only affects the front brakes as far as I can tell. Doesn't do it every time I stop nor has it done it in reverse. I have checked the brake fluid and I put the car on ramps and inspected the brake system for obvious problems like fluid leaks or loose parts and I've found nothing wrong with the brakes visually. I checked for any other problems with the suspension while I was there and didn't find anything amiss. It's almost like as I'm coming to a stop the fluid suddenly expands or the volume increases firming the pedal for a fraction of a second then returns to normal. No warning lights are on and the pads are in good shape, the rotors are less than a year old. I'm gonna pull the tires off tomorrow if it doesn't rain and have a closer look but I'm betting it's some ABS module flakiness. Any help would be appreciated. ___ http://www.okiebenz.com For new and used parts go to www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com -- -- No virus found in this incoming message. Checked by AVG - www.avg.com Version: 9.0.801 / Virus Database: 271.1.1/2822 - Release Date: 04/20/10 01:31:00 -- Kaleb C. Striplin/Claremore, OK 95 E300, 92 500SEL, 92 300SD, 92 300E 4Matic, 91 350SDL, 91 300D, 89 560SEL, 87 300SDL x2, 85 380SE 5.0 Euro, 85 190D, 84 190D, 84 300D euro manny, 76 240D, 76 300D, http://www.okiebenz.com ___ http://www.okiebenz.com For new and used parts go to www.okiebenz.com To search list archives
Re: [MBZ] 1989 Mercedes 300SE Brake weirdness
It's centered between the firewalls on the 126, has a great big 35-pin two-row connector. Ok, found and unplugged it. It disabled the ABS just fine but it still caused the ABS light to go off just like anything else I unplugged which again makes sense as you would want an indication of a failure if any of these parts failed. I experimented with a prying screwdriver and found the gage cluster is simply wedged in the dash. I removed the light bulb from the ABS indicator, pulled a relay out and all was right with the world after that. ___ http://www.okiebenz.com For new and used parts go to www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] 1989 Mercedes 300SE Brake weirdness
On Tue, Apr 20, 2010 at 7:25 AM, Dillon, Meade M CIV SPAWARSYSCEN-ATLANTIC, 53310 meade.m.dil...@navy.mil wrote: I had full steering control due to the ABS which saved my bacon and the front clip of my '87 wagon. Not that I don't know what you mean, but that's an odd term to use of a unitbody car, it strikes me. How long has it been since cars had a clip as a separate, replaceable section of the body, like the fenders? A guy on Craigslist here has been prominently advertising an '80s RWD Buick with a Euro clip, which sounds like something you give a French poodle. Alex ___ http://www.okiebenz.com For new and used parts go to www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] 1989 Mercedes 300SE Brake weirdness
that is the abs operating. If you were on dry pavement and not slipping, then the wheel sensors are probably dirty. Kathmandu wrote: Hello folks, I have some weird happinins' going on with my brakes on my 300SE. It has ABS on it and I have little experience with it in general as I have avoided the things purposely on all cars I've had until the Mercedes. I am reasonable competent in the mechanics area and I have worked on brakes before but this is new to me. Yesterday when driving home from Wally World the brakes started an odd pulsing when coming to a moderate stop. It is usually just before the car comes to a full stop, maybe a second or so. The pedal pulses up (not a softening of the pedal like a master cylinder problem) and the front brakes make a sort of twang sound like a spring vibrating. It doesn't affect the stopping ability, doesn't grab, pull to a side or anything and it only affects the front brakes as far as I can tell. Doesn't do it every time I stop nor has it done it in reverse. I have checked the brake fluid and I put the car on ramps and inspected the brake system for obvious problems like fluid leaks or loose parts and I've found nothing wrong with the brakes visually. I checked for any other problems with the suspension while I was there and didn't find anything amiss. It's almost like as I'm coming to a stop the fluid suddenly expands or the volume increases firming the pedal for a fraction of a second then returns to normal. No warning lights are on and the pads are in good shape, the rotors are less than a year old. I'm gonna pull the tires off tomorrow if it doesn't rain and have a closer look but I'm betting it's some ABS module flakiness. Any help would be appreciated. ___ http://www.okiebenz.com For new and used parts go to www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com No virus found in this incoming message. Checked by AVG - www.avg.com Version: 9.0.801 / Virus Database: 271.1.1/2822 - Release Date: 04/20/10 01:31:00 -- Kaleb C. Striplin/Claremore, OK 95 E300, 92 500SEL, 92 300SD, 92 300E 4Matic, 91 350SDL, 91 300D, 89 560SEL, 87 300SDL x2, 85 380SE 5.0 Euro, 85 190D, 84 190D, 84 300D euro manny, 76 240D, 76 300D, http://www.okiebenz.com ___ http://www.okiebenz.com For new and used parts go to www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] 1989 Mercedes 300SE Brake weirdness
Pull the ABS relay (under the black cover that says ABS) and see if the problem is still happening. The ABS system will give a short test pulse when you first take off and Kaleb is right, dirty or inoperative sensors will play havoc but the symptoms I had was that there where a few test pulses and then after a few hundred meters the ABS light would come on. Not sure about the 126 chassis but I know that 201 sensors will fit in a 124. Hendrik whose 124 has 201 ABS sensors out the front From: Kaleb C. Striplin ka...@striplin.net To: Mercedes Discussion List mercedes@okiebenz.com Sent: Tue, 20 April, 2010 10:04:21 PM Subject: Re: [MBZ] 1989 Mercedes 300SE Brake weirdness that is the abs operating. If you were on dry pavement and not slipping, then the wheel sensors are probably dirty. Kathmandu wrote: Hello folks, I have some weird happinins' going on with my brakes on my 300SE. It has ABS on it and I have little experience with it in general as I have avoided the things purposely on all cars I've had until the Mercedes. I am reasonable competent in the mechanics area and I have worked on brakes before but this is new to me. Yesterday when driving home from Wally World the brakes started an odd pulsing when coming to a moderate stop. It is usually just before the car comes to a full stop, maybe a second or so. The pedal pulses up (not a softening of the pedal like a master cylinder problem) and the front brakes make a sort of twang sound like a spring vibrating. It doesn't affect the stopping ability, doesn't grab, pull to a side or anything and it only affects the front brakes as far as I can tell. Doesn't do it every time I stop nor has it done it in reverse. I have checked the brake fluid and I put the car on ramps and inspected the brake system for obvious problems like fluid leaks or loose parts and I've found nothing wrong with the brakes visually. I checked for any other problems with the suspension while I was there and didn't find anything amiss. It's almost like as I'm coming to a stop the fluid suddenly expands or the volume increases firming the pedal for a fraction of a second then returns to normal. No warning lights are on and the pads are in good shape, the rotors are less than a year old. I'm gonna pull the tires off tomorrow if it doesn't rain and have a closer look but I'm betting it's some ABS module flakiness. Any help would be appreciated. ___ http://www.okiebenz.com For new and used parts go to www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com No virus found in this incoming message. Checked by AVG - www.avg.com Version: 9.0.801 / Virus Database: 271.1.1/2822 - Release Date: 04/20/10 01:31:00 -- Kaleb C. Striplin/Claremore, OK 95 E300, 92 500SEL, 92 300SD, 92 300E 4Matic, 91 350SDL, 91 300D, 89 560SEL, 87 300SDL x2, 85 380SE 5.0 Euro, 85 190D, 84 190D, 84 300D euro manny, 76 240D, 76 300D, http://www.okiebenz.com ___ http://www.okiebenz.com For new and used parts go to www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com ___ http://www.okiebenz.com For new and used parts go to www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] 1989 Mercedes 300SE Brake weirdness
You have had 3 or 4 responses to your note. --R On 4/20/2010 1:12 PM, Kathmandu wrote: Hello folks, I have some weird happinins' going on with my brakes on my 300SE. It has ABS on it and I have little experience with it in general as I have avoided the things purposely on all cars I've had until the Mercedes. I am reasonably competent in the mechanics area and I have worked on brakes before but this is new to me. Yesterday when driving home from Wally World the brakes started an odd pulsing when coming to a moderate stop. It is usually just before the car comes to a full stop, maybe a second or so. The pedal pulses up (not a softening of the pedal like a master cylinder problem) and the front brakes make a sort of twang sound like a spring vibrating. It doesn't affect the stopping ability, doesn't grab, pull to a side or anything and it only affects the front brakes as far as I can tell. Doesn't do it every time I stop nor has it done it in reverse. I have checked the brake fluid and I put the car on ramps and inspected the brake system for obvious problems like fluid leaks or loose parts and I've found nothing wrong with the brakes visually. I checked for any other problems with the suspension while I was there and didn't find anything amiss. It's almost like as I'm coming to a stop the fluid suddenly expands or the volume increases firming the pedal for a fraction of a second then returns to normal. No warning lights are on and the pads are in good shape, the rotors are less than a year old. I'm gonna pull the tires off tomorrow if it doesn't rain and have a closer look but I'm betting it's some ABS module flakiness. Any help would be appreciated. ___ http://www.okiebenz.com For new and used parts go to www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com ___ http://www.okiebenz.com For new and used parts go to www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] 1989 Mercedes 300SE Brake weirdness
Sorry about the double post. I read the list was down and to resend my posting so I did. I'm going to try cleaning the sensors and check the relay, thanks to those who responded. ___ http://www.okiebenz.com For new and used parts go to www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] 1989 Mercedes 300SE Brake weirdness
Pull the ABS relay (under the black cover that says ABS) and see if the problem is still happening. The ABS system will give a short test pulse when you first take off and Kaleb is right, dirty or inoperative sensors will play havoc but the symptoms I had was that there where a few test pulses and then after a few hundred meters the ABS light would come on. Not sure about the 126 chassis but I know that 201 sensors will fit in a 124. Hendrik whose 124 has 201 ABS sensors out the front I cleaned them off and it made no difference. I'm assuming there are two on each wheel up front and one on the differential? That's the only sensor I could find on the entire rear section of the car. Is there any easy (cheap) way to test the sensors? I did pull the relay and the pulsing stopped so it is in the ABS system. Our '90 SEL was doing this, and it really annoyed my wife. Cleaning the front sensors didn't help, and the overvoltage relay was all right. So I just unplugged the ABS brain. Few of our cars have ABS, and as often as not (in snow or gravel) for us here the ABS is actually harmful. (It's good on glare ice, of course.) She's happy now. -- Jim Any way to disconnect this and turn off the ABS light? Other than black tape or pulling the instrument cluster to remove the bulb that is. ___ http://www.okiebenz.com For new and used parts go to www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] 1989 Mercedes 300SE Brake weirdness
Any way to disconnect this and turn off the ABS light? Other than black tape or pulling the instrument cluster to remove the bulb that is. Que? Doesn't the ABS brain run the ABS light? Unplug the brain, and it's done. On the 126, it's trivial. -- Jim ___ http://www.okiebenz.com For new and used parts go to www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] 1989 Mercedes 300SE Brake weirdness
Any way to disconnect this and turn off the ABS light? Other than black tape or pulling the instrument cluster to remove the bulb that is. Que? Doesn't the ABS brain run the ABS light? Unplug the brain, and it's done. On the 126, it's trivial. Well, nothing in my life is trivial. I pulled both relays one at a time then together and the light stayed on then I pulled the plug off of the ABS box and the light stayed on. It makes sense to me since a failure of the connection should cause the light to come on. Maybe I'm unplugging the wrong plug but it is the only one obviously going to the black block that has ABS on it. Is the brain elsewhere? ___ http://www.okiebenz.com For new and used parts go to www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
