My mother just had a set of new tires put on her 2003 Jeep Wrangler. (They’re Michelin LTX M/S2 tires; the previous ones were LTX M/S.) Immediately after the new tires were put on, she noticed a difference in braking; she says that it takes a lot more force on the pedal to stop the vehicle than it did before the tire change. She also reports that braking from high speeds produces a very, very brief feeling similar to loss of traction. I drove the vehicle earlier this week; the brakes were noticeably different, but I never felt like I was having trouble stopping. The braking issue does not become worse during driving, and has not become worse since the tire change. Something is definitely not right though. She’s taking it back to the shop this week, but I would like some input before she heads back in with it…anyone have any ideas?
Check the tire pressure.
Doesn’t sound right. Did they throw in a free safety inspection? My guess is they messed with the calipers checking the pads. One big thing is keeping the calipers moving freely. Your mother likely drives conservatively like my wife and I. Brake lining last a long time and wears unevenly because time and the environment gets to the hardware first.
I just replaced 3 year old lining on my 02 Cavalier Monday. 3 of the 4 pads still had plenty of lining, but one corner of one pad was almost down to the backing plate. I had a terrible time getting the bolts out because they didn’t want to turn in the rubber bushings. I don’t see how the caliper could have been sliding freely like it should. It was still braking fine, and left alone, may have done so until the screechers let me know the one pad was gone.
Once you mess with old stuff like that, it may not work right until the bolts and bushings are at least cleaned up if not replaced. Which I did along with the new lining. Note, 3 years ago, I had rebuilt the calipers and cleaned up and lubed the bolts and bushings with Sil-Glyde. The bolt threads got antiseize. Same again this time.
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I just replaced 3 year old lining on my 02 Cavalier Monday. 3 of the 4 pads still had plenty of lining, but one corner of one pad was almost down to the backing plate. I had a terrible time getting the bolts out because they didn’t want to turn in the rubber bushings. I don’t see how the caliper could have been sliding freely like it should. It was still braking fine, and left alone, may have done so until the screechers let me know the one pad was gone.
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don’t mean to hijack the thread but you need to check the proportional valve in the master cylinder of your brake system. At least thats what the problem was when my brakes wore out unevenly like you described.
As to the OP, yep take it back to the shop, they did something, forgot to tighten something, maybe bled some brake fluid out for some reason and failed to replace it or something. feeling of loss of traction, that one throws me, only thing I can think of off hand with the info you’ve given is something to do with the suspension but I can’t think of what it would be.
As to the OP, yep take it back to the shop, they did something, forgot to tighten something, maybe bled some brake fluid out for some reason and failed to replace it or something. feeling of loss of traction, that one throws me, only thing I can think of off hand with the info you’ve given is something to do with the suspension but I can’t think of what it would be.
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crap also meant to say that suspension issues doesn’t seem like it would be correct, just for some reason comes to mind.
Tire shops are great for overtightening lugnuts. Maybe they tightened them unevenly and over-torqued in spots. The rotors could be pulled out of their true position and change the feel of the braking.
Does an '03 Wrangler still have rear drums? (Heck, does a '12 Wrangler still have 'em?)
The only time they do anything other than take the wheels off for a typical “free brake inspection” is if they have to pull brake drums off. It could be that they had to back off the shoes a little to pull the drums off and the shoes have yet to readjust themselves. This can definitely lead to the brakes not feeling quite right, but still being able to stop the car okay.
The brake shoes adjust themselves when you brake and come to a complete stop when moving backwards, so doing a bunch of backwards stops in a parking lot or somewhere else safe might fix it.
Or they used PB Blast to free up parts, or some other lubricant, and it’s all over the place, and the rotors/drums are cleaner than ever and slightly greaey. Would explain the feeling.
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Has the position of the driver’s seat changed? A change from one’s most comfortable seating position can cause perception of performance changes, believe it or not.
Perhaps it is my conservative driving again, but I have had bad luck keeping auto adjusters working. I end updoing them by hand.
The driver’s seat thing sounds possible.
Thanks for all the replies! I’ve never really had to deal with brake/tire issues that are this troubling, and my searches were letting me down. I’ll be sure to post an update (the appointment is Saturday).
The crew that was on hand Saturday removed all the tires; they found no issues with the brakes. My mom has reported some improvement with the feel of the brakes, but they still don’t feel right to her; she’s planning to make another appointment so the shop foreman can investigate the issue. (To the shop’s credit, they did not charge for this visit.)
It sounds like the brakes are fading. Try having the shop bleed the brake lines. Removing the little air bubbles from within the brake lines should make a difference. If it doesn’t help much, it probably needed to be done anyways.
Brake fade and having air in the line are very different issues. Brake fade you have a nice high pedal, it is just that pushing on it does little. You may also have a sort of burned phenolic smell. It usually follows hard use. Driving with the parking brake on can cause it too. Perhaps that is the problem. The shop tricked her by setting the parking brake which she never does. They didn’t set it tightly enough to keep her from driving off and glazing the rear brakes. Most new cars have warnings to prevent that.
Bleeding the brakes relieves a low, spongy pedal due to the air in the system compressing.
Has she broken in the tires? 500 miles of easy driving is often recommended. The mold release compound applied to the tires during curing has to be worn off the tread. The conditions described (mushy braking and feeling of slippage) are exactly what happens with new tires.
New tires have increased tread depth (duh, that’s why the old ones were replaced, I know). This actually decreases traction, handling, and braking initially due to tread squirm. The tire tread will deflect more before transfering the side/braking load to the carcass of the tire/wheel/suspension/car/steering wheel/brake pedal. That’s why autocross and road racers use tires with shaved treads, minimal grooves, or slicks to increase handling and feel.
I don’t know the specific tires involved; I suspect they are (Jeep vehicle) heavily ribbed. Most likely the “strange” feel is a combination of the mold release compound along with the newer deeper tread.
Of course you’re wise to have the systems checked out professionally, but the solution may just be more miles on the tires.
My vote would be for inadequately bled brakes.
Still… if her tires were super-bald before they got replaced, it could be that they were acting more like racing slicks and giving her a super-big contact patch that the new tires with actual tread aren’t giving her.
It doesn’t feel like brake fade to me – I’ve definitely experienced that (in another vehicle). The braking power is there, in my opinion…it just doesn’t feel ‘right’. The old tires were not super-bald, but they were noticeably worn; the tread on the new tires definitely looks a lot deeper in comparison. And there definitely hasn’t been much of a break-in period.