Strange Brake Problem. I have tried just about everything...
#1
Contributing Member
Thread Starter
Join Date: Jun 2003
Location: Bethlehem, GA
Posts: 1,067
Likes: 0
Received 0 Likes
on
0 Posts
Strange Brake Problem. I have tried just about everything...
I am having a really strange problem with my brakes. I have a 99 Limited with ABS. I have noticed 2 different scenarios when this happens. First, If I encounter loose gravel on top of pavement, and I am braking normally at an intersection. My brakes feel like they give out and I get this back pressure that 'fights' my foot up and down until I completely stop, then it is fine. Second, I have this one intersection near my house that is sloped about 20% right to left...like this /. The road continues but my road is to the right in the middle of the turn. When i go to turn right at the intersection, essentially going over a hump because the road drops off on the other side. more often than not I get the same occurance. The right front tire never leaves the pavement but the weight is shifted to the left substantially. It feels like the pressure is reversed and i get this back pressure that makes the brakes shudder. If that makes sense. I can feel the brake pedal pulsating backwards and at that time, there are no brakes for a few seconds. Kinda scary. I had this happen on slightly wet pavement one other time while stopping at an intersection. It feels like the ABS doesnt engage. I have replaced the calipers, pads, rotors, brake lines and had the brakes bled numerous times. Things I am considering are master cylinder, brake booster, and possibly some kind of vacuum problem. Anyone experienced this strange problem?
#2
I have had the same thing happen. I think the shuddering IS the ABS kicking in. But thats just a guess. When I am stopping and hit a bump or wet roads I think my ABS kicks in a bit early and does what you described. If anyone has any answers to this that would be great.
#3
Registered User
Join Date: Dec 2005
Location: Columbia, SC
Posts: 702
Likes: 0
Received 0 Likes
on
0 Posts
Yeah, your descriptions sound like normal ABS operation to me. Your post count is pretty high so I am betting that you know how ABS works but the system will vibrate the pedal to let you know that it is reducing the amount of brake being applied to keep the wheels from locking up.
This is a little off topic but people complain that ABS sucks and locking up the wheels will stop them faster. While this may or may not be true, it is true that you cannot change direction while your wheels are not rolling at all. That is the beauty of ABS, it will at least give you chance to steer clear of any obstacle in your way.
This is a little off topic but people complain that ABS sucks and locking up the wheels will stop them faster. While this may or may not be true, it is true that you cannot change direction while your wheels are not rolling at all. That is the beauty of ABS, it will at least give you chance to steer clear of any obstacle in your way.
#5
Contributing Member
Thread Starter
Join Date: Jun 2003
Location: Bethlehem, GA
Posts: 1,067
Likes: 0
Received 0 Likes
on
0 Posts
Well I guess. It just seems squirly to me. I guess the ABS is freaking out because there is nothing for the tires to grab onto while traversing the gravel and it applies the back pressure to comensate for that?
#6
Registered User
Join Date: Oct 2007
Location: Tuscaloosa, AL
Posts: 705
Likes: 0
Received 0 Likes
on
0 Posts
same thing happened to me last year when hunting...i was goin about 55 on a paved road and needed to turn around, so when i had slowed to about 15-20, i eased off the road while mashing the brakes, and once i hit the loose gravel on the roadside, it felt like it was shuddering...but good to know it's normal operation of the ABS, as it kinda scared me... lol!
#7
Registered User
Join Date: Aug 2003
Location: Fort Worth, TX. USA.
Posts: 171
Likes: 0
Received 0 Likes
on
0 Posts
I am having a really strange problem with my brakes. I have a 99 Limited with ABS. I have noticed 2 different scenarios when this happens. First, If I encounter loose gravel on top of pavement, and I am braking normally at an intersection. My brakes feel like they give out and I get this back pressure that 'fights' my foot up and down until I completely stop, then it is fine. Second, I have this one intersection near my house that is sloped about 20% right to left...like this /. The road continues but my road is to the right in the middle of the turn. When i go to turn right at the intersection, essentially going over a hump because the road drops off on the other side. more often than not I get the same occurance. The right front tire never leaves the pavement but the weight is shifted to the left substantially. It feels like the pressure is reversed and i get this back pressure that makes the brakes shudder. If that makes sense. I can feel the brake pedal pulsating backwards and at that time, there are no brakes for a few seconds. Kinda scary. I had this happen on slightly wet pavement one other time while stopping at an intersection. It feels like the ABS doesnt engage. I have replaced the calipers, pads, rotors, brake lines and had the brakes bled numerous times. Things I am considering are master cylinder, brake booster, and possibly some kind of vacuum problem. Anyone experienced this strange problem?
Last edited by progress4m; 12-10-2007 at 02:03 PM.
Trending Topics
#8
Registered User
Join Date: Aug 2003
Location: San Diego, CA
Posts: 987
Likes: 0
Received 0 Likes
on
0 Posts
The purpose of this is to allow the driver to maintain steering control under heavy braking and, in some situations, to shorten braking distances (by allowing the driver to hit the brake fully without the fear of skidding or loss of control). Disadvantages of the system include increased braking distances under certain conditions and the creation of a "false sense of security" among drivers who do not understand the operation and limitations of ABS.
from: http://en.wikipedia.org/wiki/Anti-lock_braking_system
#9
Registered User
Join Date: Mar 2005
Location: Castle Rock, CO
Posts: 13
Likes: 0
Received 0 Likes
on
0 Posts
Sometimes the ABS gets overly aggressive, not sure how common this is on 4runners, but on Land Cruiser's it is common to go over a speed-bump or pothole and be gently on the brake and the ABS goes nuts and then you freak out because the vehicle doesn't want to stop. Taking the ABS sensors out and cleaning them off (they are a magnet and will gather up any metal shavings/pieces wandering around in the birfield grease)...however, that of course is only for a Land Cruiser. Though I guess the 4runner ABS sensors could have some random metal bits on them, though I don't know where they would come from.
My 4runner has done something similar, and on a slushy road it's a bit of a pain, it does help to just push the brake pedal down harder, at least in my experience...still pulses, but the vehicle stops better/quicker than trying to ease up on the brake pedal pressure.
#11
Registered User
Join Date: Oct 2007
Location: Tuscaloosa, AL
Posts: 705
Likes: 0
Received 0 Likes
on
0 Posts
#13
Contributing Member
#14
Registered User
#15
Contributing Member
#16
Registered User
Thread
Thread Starter
Forum
Replies
Last Post
theking11863
Vehicle Audio & Home Entertainment
2
03-19-2016 09:36 PM
Dennisx2
General Electrical & Lighting Related Topics
0
08-04-2015 01:26 PM