Problems after replacing master cylinder
in [Technical]
|
From: jim on 23 Apr 2010 18:52 Mark wrote: > Are you folks suggesting that the P0446 CEL and the problems I > described earlier with the vibrating and brake master cylinder are > related? Sorry, some of this is way too technical for me. Thanks ! No I don't think anyone suggested your DTC code and the brake/vibration were related. The code means it failed one of the diagnostic tests that are done on the system designed to keep raw fuel vapors from getting into the environment. -jim
From: Tegger on 24 Apr 2010 11:26 Mark <muffi74(a)hotmail.com> wrote in news:4e4c6382-8b8a-41d9-bbc9- 1c9b94cdb1e4(a)5g2000yqj.googlegroups.com: > Are you folks suggesting that the P0446 CEL and the problems I > described earlier with the vibrating and brake master cylinder are > related? Sorry, some of this is way too technical for me. Thanks ! No relation at all between P0446 and the master cylinder. -- Tegger
From: Mark on 4 May 2010 19:30 On Apr 6, 10:31 am, jim <"sjedgingN0Sp"@m(a)mwt,net> wrote: > lugnut wrote: > > > On Mon, 5 Apr 2010 18:33:16 -0700 (PDT), Mark > > <muff...(a)hotmail.com> wrote: > > > >Hi, > > > >I have a lexus es300 with 128K miles. I had taken my car to the > > >mechanic as I felt the brakes needed work. I had to press the brake > > >pedal all the way down to stop the car. The mechanic suggested > > >replacing the master cylinder which I did. > > > >Now, I have 2 unique problems and I am looking for advice here to > > >educate myself before I take the car back to the mechanic. > > > >1. The brake pedal sometimes works just by a little pressing, and > > >other times I need to press it all the way down. In other words, > > >sometimes it brakes just by a slight touch of the foot and sometimes > > >it doesn't. The brakes work, just that the "firmness" of the pedal > > >keeps changing. > > > >2. The car starts vibrating after driving for about 10 minutes on the > > >highway. The vibration doesn't start right away. There is vibration in > > >the car and the steering. When I brake, I get the pulsating feeling > > >with the brake pedal. All the passengers in the car can feel the > > >vibration. After about 15 minutes of driving, the vibration goes away > > >and doesn't come back during the same ride. If I park the car, let it > > >cool and drive again, then the same pattern repeats. > > This part sounds like a stuck caliper. What happens is when you apply > the brakes, the pressure is being applied to only one side of the rotor > because the caliper can't move freely. That means even the tiniest > amount of run out in the rotor causes pulsation. If the caliper weren't > stuck it would float with the sideways movement of the rotor. If the > caliper can move freely a small amount of runout wouldn't cause > pulsation. > It also sounds like when things get warmed up the problem disappears. > That would mean the problem is related to temperature. If your > description is accurate as things start to warm up the problem gets > worse before it gets better. This is unusual and I can't think of a > reason that would be happening, but possibly something wasn't assembled > correctly. > > if you have a stuck caliper things could be getting extremely hot. That > could explain the intermittent pedal to the floor if you are getting > things hot enough to boil brake fluid. > > -jim > > > > > >Could the experts here give some insight into what the possible issues > > >could be? The advice here has always helped me in the past and look > > >forward to your opinion. > > > >Thanks and regards, > > >Mark > > > Your problem sounds like the booster is not releasing which > > results in your brakes being partially applied. This > > explains both the low inconsistant pedal and the brake > > pulsation after driving a couple of minutes. You may be > > able to use your toe and lift the pedal to clear the problem > > until you apply the brake again. If the master cylinder was > > replaced, the mechanic may not have been able to effectively > > bleed the system to purge air from it. > > > As an aside, it is usually best to replace both the booster > > and master cylinder if one fails and they are essentially > > the same age with significant miles on them. In you rcase > > at this point, I would have the booster replaced and the > > hydraulic system purge following the procedure in the > > manufacturer's service manual to be sure the ABS system is > > cleared. That year model may also require a scanner to > > correctly purge the ABS controller. You may want to have > > the brake pads checked for heat damage, glazing, cracking, > > disintegration, etc. to make sure the brakes are good to go. > > I had this happen on my CV a couple of years back right > > after a brake job. The pads were destroyed in less than 50 > > miles after the problem began. > > > Lugnut Just an update... after bleeding the brake system again, the problem with pedal to the floor has been resolved and now my braking is a lot more consistent. But the vibration problem still exists. To summarize, the steering wheel starts vibrating after about 10 minutes on the highway. After another 15 minutes, the vibration goes away and then the ride is smooth. During vibration, the brake pedal pulsates while braking and increases the vibration in the steering. Do you have any other suggestions? Would a road force balancing help? Thanks a lot again for your help.
From: Nate Nagel on 4 May 2010 21:45 On 05/04/2010 07:30 PM, Mark wrote: > On Apr 6, 10:31 am, jim<"sjedgingN0Sp"@m(a)mwt,net> wrote: >> lugnut wrote: >> >>> On Mon, 5 Apr 2010 18:33:16 -0700 (PDT), Mark >>> <muff...(a)hotmail.com> wrote: >> >>>> Hi, >> >>>> I have a lexus es300 with 128K miles. I had taken my car to the >>>> mechanic as I felt the brakes needed work. I had to press the brake >>>> pedal all the way down to stop the car. The mechanic suggested >>>> replacing the master cylinder which I did. >> >>>> Now, I have 2 unique problems and I am looking for advice here to >>>> educate myself before I take the car back to the mechanic. >> >>>> 1. The brake pedal sometimes works just by a little pressing, and >>>> other times I need to press it all the way down. In other words, >>>> sometimes it brakes just by a slight touch of the foot and sometimes >>>> it doesn't. The brakes work, just that the "firmness" of the pedal >>>> keeps changing. >> >>>> 2. The car starts vibrating after driving for about 10 minutes on the >>>> highway. The vibration doesn't start right away. There is vibration in >>>> the car and the steering. When I brake, I get the pulsating feeling >>>> with the brake pedal. All the passengers in the car can feel the >>>> vibration. After about 15 minutes of driving, the vibration goes away >>>> and doesn't come back during the same ride. If I park the car, let it >>>> cool and drive again, then the same pattern repeats. >> >> This part sounds like a stuck caliper. What happens is when you apply >> the brakes, the pressure is being applied to only one side of the rotor >> because the caliper can't move freely. That means even the tiniest >> amount of run out in the rotor causes pulsation. If the caliper weren't >> stuck it would float with the sideways movement of the rotor. If the >> caliper can move freely a small amount of runout wouldn't cause >> pulsation. >> It also sounds like when things get warmed up the problem disappears. >> That would mean the problem is related to temperature. If your >> description is accurate as things start to warm up the problem gets >> worse before it gets better. This is unusual and I can't think of a >> reason that would be happening, but possibly something wasn't assembled >> correctly. >> >> if you have a stuck caliper things could be getting extremely hot. That >> could explain the intermittent pedal to the floor if you are getting >> things hot enough to boil brake fluid. >> >> -jim >> >> >> >>>> Could the experts here give some insight into what the possible issues >>>> could be? The advice here has always helped me in the past and look >>>> forward to your opinion. >> >>>> Thanks and regards, >>>> Mark >> >>> Your problem sounds like the booster is not releasing which >>> results in your brakes being partially applied. This >>> explains both the low inconsistant pedal and the brake >>> pulsation after driving a couple of minutes. You may be >>> able to use your toe and lift the pedal to clear the problem >>> until you apply the brake again. If the master cylinder was >>> replaced, the mechanic may not have been able to effectively >>> bleed the system to purge air from it. >> >>> As an aside, it is usually best to replace both the booster >>> and master cylinder if one fails and they are essentially >>> the same age with significant miles on them. In you rcase >>> at this point, I would have the booster replaced and the >>> hydraulic system purge following the procedure in the >>> manufacturer's service manual to be sure the ABS system is >>> cleared. That year model may also require a scanner to >>> correctly purge the ABS controller. You may want to have >>> the brake pads checked for heat damage, glazing, cracking, >>> disintegration, etc. to make sure the brakes are good to go. >>> I had this happen on my CV a couple of years back right >>> after a brake job. The pads were destroyed in less than 50 >>> miles after the problem began. >> >>> Lugnut > > Just an update... after bleeding the brake system again, the problem > with pedal to the floor has been resolved and now my braking is a lot > more consistent. But the vibration problem still exists. To summarize, > the steering wheel starts vibrating after about 10 minutes on the > highway. After another 15 minutes, the vibration goes away and then > the ride is smooth. During vibration, the brake pedal pulsates while > braking and increases the vibration in the steering. Do you have any > other suggestions? Would a road force balancing help? > > Thanks a lot again for your help. I would check your master cylinder pushrod adjustment. It may be slightly applying the brakes causing the rotors to temporarily warp. This isn't particularly good for your pads, rotors, calipers, etc. nate -- replace "roosters" with "cox" to reply. http://members.cox.net/njnagel
From: jim beam on 4 May 2010 21:55
On 05/04/2010 04:30 PM, Mark wrote: > On Apr 6, 10:31�am, jim<"sjedgingN0Sp"@m(a)mwt,net> wrote: >> lugnut wrote: >> >>> On Mon, 5 Apr 2010 18:33:16 -0700 (PDT), Mark >>> <muff...(a)hotmail.com> wrote: >> >>>> Hi, >> >>>> I have a lexus es300 with 128K miles. I had taken my car to the >>>> mechanic as I felt the brakes needed work. I had to press the brake >>>> pedal all the way down to stop the car. The mechanic suggested >>>> replacing the master cylinder which I did. >> >>>> Now, I have 2 unique problems and I am looking for advice here to >>>> educate myself before I take the car back to the mechanic. >> >>>> 1. The brake pedal sometimes works just by a little pressing, and >>>> other times I need to press it all the way down. In other words, >>>> sometimes it brakes just by a slight touch of the foot and sometimes >>>> it doesn't. The brakes work, just that the "firmness" of the pedal >>>> keeps changing. >> >>>> 2. The car starts vibrating after driving for about 10 minutes on the >>>> highway. The vibration doesn't start right away. There is vibration in >>>> the car and the steering. When I brake, I get the pulsating feeling >>>> with the brake pedal. All the passengers in the car can feel the >>>> vibration. After about 15 minutes of driving, the vibration goes away >>>> and doesn't come back during the same ride. If I park the car, let it >>>> cool and drive again, then the same pattern repeats. >> >> This part sounds like a stuck caliper. What happens is when you apply >> the brakes, the pressure is being applied to only one side of the rotor >> because the caliper can't move freely. That means even the tiniest >> amount of run out in the rotor causes pulsation. If the caliper weren't >> stuck it would float with the sideways movement of the rotor. If the >> caliper can move freely �a small amount of runout wouldn't cause >> pulsation. >> � � � � It also sounds like when things get warmed up the problem disappears. >> That would mean the problem is related to temperature. If your >> description is accurate as things start to warm up the problem gets >> worse before it gets better. This is unusual and I can't think of a >> reason that would be happening, but possibly something wasn't assembled >> correctly. >> >> � � � � if you have a stuck caliper things could be getting extremely hot. That >> could explain the intermittent pedal to the floor if you are getting >> things hot enough to boil brake fluid. >> >> -jim >> >> >> >>>> Could the experts here give some insight into what the possible issues >>>> could be? The advice here has always helped me in the past and look >>>> forward to your opinion. >> >>>> Thanks and regards, >>>> Mark >> >>> Your problem sounds like the booster is not releasing which >>> results in your brakes being partially applied. �This >>> explains both the low inconsistant pedal and the brake >>> pulsation after driving a couple of minutes. �You may be >>> able to use your toe and lift the pedal to clear the problem >>> until you apply the brake again. �If the master cylinder was >>> replaced, the mechanic may not have been able to effectively >>> bleed the system to purge air from it. >> >>> As an aside, it is usually best to replace both the booster >>> and master cylinder if one fails and they are essentially >>> the same age with significant miles on them. �In you rcase >>> at this point, I would have the booster replaced and the >>> hydraulic system purge following the procedure in the >>> manufacturer's service manual to be sure the ABS system is >>> cleared. �That year model may also require a scanner to >>> correctly purge the ABS controller. �You may want to have >>> the brake pads checked for heat damage, glazing, cracking, >>> disintegration, etc. to make sure the brakes are good to go. >>> I had this happen on my CV a couple of years back right >>> after a brake job. �The pads were destroyed in less than 50 >>> miles after the problem began. >> >>> Lugnut > > Just an update... after bleeding the brake system again, the problem > with pedal to the floor has been resolved and now my braking is a lot > more consistent. But the vibration problem still exists. To summarize, > the steering wheel starts vibrating after about 10 minutes on the > highway. After another 15 minutes, the vibration goes away and then > the ride is smooth. During vibration, the brake pedal pulsates while > braking and increases the vibration in the steering. Do you have any > other suggestions? Would a road force balancing help? > > Thanks a lot again for your help. i made some suggestions and they're known to work for hondas. did you try them on the lexus? it's a common issue with modern lightweight hubs. -- nomina rutrum rutrum |