I'm looking for a bit of advice on a recent problem with my 2014 GX 460. It's all stock, except for upgraded infotainment. The problem I'm having is that the brakes have become overly aggressive and sensitive. It's very hard to modulate the brakes to come to a smooth stop. They suddenly in the middle of stopping become much more aggressive. I suspect the master cylinder may be the culprit but would like to be more sure of this before spending that kind of money. Any thoughts and advice would be appreciated. Thanks.
Super sensitive brakes, 14 GX460
- Thread starter WoodstockGXer
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- #2
I should probably add, the pads and rotors are in good shape, replaced within the past 6 months. The GX has 124 K miles.
r2m
Richard
Did a shop do the pads and rotors? If so, take it back to them and have them take a look at it.
But my first thought was the rotors, alas, as you mentioned, they're new so that shouldn't be the issue.
But my first thought was the rotors, alas, as you mentioned, they're new so that shouldn't be the issue.
All of the normal brake problems I can think of would make the brakes weaker rather than stronger.
Maybe the proportioning valve is malfunctioning and instead of the usual rear bias on light braking is biasing to the front? Is the ABS going off too easily in the rear?
Maybe the proportioning valve is malfunctioning and instead of the usual rear bias on light braking is biasing to the front? Is the ABS going off too easily in the rear?
Does it happen more after driving awhile? I’ve seen contaminated brake fluid cause the brakes to hang up or drag. And in worse situations they can seize. Oil in brake fluid causes swelling of anything rubber in the system. This is a long shot but maybe something to look at. Especially if you’ve had recent repairs or service.
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Thanks guys. I appreciate the input. It is strange. There are no codes thrown or warning lights. The ABS doesn't activate. It happens after driving for a bit. The first few stops are fine. The brake pedal will start to feel hard and going closer to the floor. Fluid and rotors are good. I'm leaning toward something to do with the brake assist feature or as you say, ericm979, the proportioning valve. I may have to bite the bullet and take it to the dealer. I'll post here what it turns out to be.
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Update: I went to the dealer. To make a long story short, they wanted to do a full brake job since it didn't have Lexus pads on it at a cost of $1100 even though they were not worn very much at all. When I asked what if this doesn't fix it, after a long sermon on the quality of Lexus parts, they said I'd still have to pay if it did not resolve the issue. I told them I did not want to bet $1100 on that diagnosis and asked for the keys. I have to give them a bit of credit, they mentioned a $180 diagnostic fee when I dropped it off which I would have happily paid for an accurate diagnosis, but in the end though they did not charge me anything.
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Rear are Akebono ProAct, don't recall the brand of the front but they were definitely not the cheap ones. I've changed both front and rear pads, no difference.
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They said they checked it out and didn't find an issue. I don't feel their investigation went very deep though.
When I put OE rotors and pads on recently I was surprised to see "AKEBONO" stamped on the back of the pads. Might be a different compound than the aftermarket ones but it's at least the same company.
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- #14
That's interesting.
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- #15
Update: I've swapped the front pads again. This is the 3rd set. I went with the Akebono ProAct pads which now match the rears. The problem has gone away. It seems the lesser quality front pads were causing the issue. The most recent ones I've removed where Carquest Platinum. This has been my experience. As always, your mileage may vary. Thanks for the input y'all.
re_guderian
SILVER Star
Glad you got it resolved. "Super Sensitive" and "GX Brakes" are word combos that you rarely hear with the GX... I'm usually like, "damn, is this thing gonna stop???"
