I don't know what it could be....

Ok. I live in PA and it has been snowy here for the past week.

Right before the snow I had a flat tire so I got a new tire put on my factory rims. Same as the factory supplied tires. Potenza 92R.

Well then it snowed. Everyhting seemed fine. I had a lot of antilock break feeddback on the icy roads. But that is normal. Then the next day I noticed a problem. The roads were fine no ice or anything and I felt my breaks acting strange.

When I am doign like 30-40MPH or more I apply my brakes and they feel very stiff. They are stiffer than normal. Then as I slow down to about 20 they let or or get soft and travle down some. Then I get a little ABS feeback in the pedal and it hits another poitn where it gets stiff again.

The car stops but this concearns me and I have no idea what it could be.

Anybody have any ideas or suggestions????

anybody?

I don't know, sorry. It sounds really strange. Maybe changing your brake fluid would fix it or just take it to the dealer under warranty. A tire will not affect the braking like that.

How many miles are on the other tires? With AWD you should really change all 4 tires at the same time. If you can't I think the tire shops have a machine that will shave the new tire down to match the older tires.

p@
www.achtuning.com

are you serious.

My tires have maybe 10000 miles on them. Not much wear. But I feel no affects while driving just while braking.

It depends on how much wear is on them. What happens is if the other tires are smaller than the new one they will be spinning faster than the new one, that is really hard on the differentials over a long period of time and will eventually damage it. There is a tolerance for tire size but I can't remember off the top of my head what it is.

p@

Check your owners manual about how much of a difference there can be between two different tire sizes with wear.

So what is the different. I will look at my manual tonight.

If I have one new tire that is bigger than the rest what are my options???

Does that mean I have to get 4 totally new tires? Or can I get the new tire shaved or worn in to the same level as the existing tires?

I don't want this to end up costing me an arm and a leg???

What are my options here?

DO you really think that a tire size different would cause such a noticable change in the brake feel and pressure and loss of pressure? I could see it affection the ABS but the brake feel itself????

If the sizes were off wouldn't I feel a difference in performance and ride when doing 50MPH and not applying the brakes?

No because the would be the part that is taking the abuse is are the differentials and they won't let you know until its too late.

I saw someone on another post in the brake forum had the tire tolerance. It was 1/8" or 1/4" circumferance.

I'm not saying this is your problem but you might want to check your tires. Take them off and measure them with a flexable tape measure. I am disapointed at the tire shop, they should have told you about this, I was in a Discount tire a few years ago and they refused to sell a guy one tire because he had a car with AWD.

p@

Can I simply buy another new tire to match up on the other side of the car or do all 4 tires have to be the same?

The guy at the dealership told me that all 4 tires have to be the same size. I don't understand why. I can see having both front tires the same and both rear tires the same but why all 4?

Hey, which tire is the the one you replaced? ex. front left , right rear?

Originally posted by jasno999
Can I simply buy another new tire to match up on the other side of the car or do all 4 tires have to be the same?

The guy at the dealership told me that all 4 tires have to be the same size. I don't understand why. I can see having both front tires the same and both rear tires the same but why all 4?
again, it's because we have AWD with center diff, which provides the functiion of MATCHing the front and rear speed. so, if front wheels are spinning faster than rear, the center diff will start to cook :)

you should also ask the dealer/tech about your overall brake system. things like the pedal dropping to the floor slowly is NOT caused by tires.

Originally posted by KinjoX
Hey, which tire is the the one you replaced? ex. front left , right rear?

It really does not matter which tire he replaced because he needs to make sure that the size difference between each tire falls within the mechanical tolerable areas.

Dealer told me warranty is void cause I have x-drilled/slotted rotors.

I took my car in for service today cause I am havign brake problems. Before he even got in the car he told me I voided my warranty cause I changed one part on the brake system so the entires system was voided when it came to the warranty.

Is this true. Cany they do that. What if my master cylinder is broken. Can they actualyl say it was caused my different rotors on the car and not pay for it under warranty?

I need some infor from you guys. Anybody else had similar problems?

Originally posted by jasno999
Dealer told me warranty is void cause I have x-drilled/slotted rotors.

I took my car in for service today cause I am havign brake problems. Before he even got in the car he told me I voided my warranty cause I changed one part on the brake system so the entires system was voided when it came to the warranty.

Is this true. Cany they do that. What if my master cylinder is broken. Can they actualyl say it was caused my different rotors on the car and not pay for it under warranty?

I need some infor from you guys. Anybody else had similar problems?

The dealer can't void your warranty
SOA has to
My dealer and local rep are cool and would never void the warranty for something as gay as that.

99% sure the problem is the new tire, measure the circumference of the new and old tires..if it's close to a 1/4 inch there's your problem.

Are the rotors larger than stock? If not cross drilling and slots will make no difference. Rotors are a wear item and replacing them will not void any warranty. Just like brake pads, if you have good pads that will not void your warranty. But I can see where they are comming from if they are big rotors.

Replace the 3 worn tires. Actually take this time to get good tires. You don't have to get super expensive tires to get a good set. Anything is better than the RE-92's.

p@

I told the guy about the tire. HE said yes it can cause Diff problems but nothing with the brakes. He sees no reason how it would affect the brakes on the car.


i did a very simple coin measure. Put a quarter in the tread of the ned and old. And from my determination on that the tred difference is 1/8 total or 1/16 on each side.