ani one here had a abs problem ..

my brake pedal got hard all off suden after switching off my 19's back to my coupe stocks 18" .. reason idk why .. but problems are .. brake pedal is hard and its harder when i press all the way down and when i let go off the gas pedal i hear air .. relly weird .. and if i go on the freeway after i pass 60mph my abs-slip and vdc will go on . and then the brake pedal will be smooth ..

so took it to 2 shops 1 said i will have to take it to dealer because its a abs problem ..

2nd one said it could be a abs sensor or somthing else but will have to wait for them to see it and thats till monday ... dang what iam i gonna do


has anione here had this type off problem .,.


oh and my gsedan is 03

 

Have you ran the coupe 18's on your sedan before? Do they still have staggered tire sizes? I'm not sure how much of a staggered size(or diameter difference) the sedan accepts. If it does, make sure the wider tires are in the rear and see if that works. I'd check the air pressure also.

Try putting on the 19's back on and see if you still have problems. I don't hear too many problems with the G's ABS system other than people with modified suspension and camber kits.

 

well i put smaller tires in the front i have 235-40-18 and back got 245-45-18 i used to have the 245 in the fronts also but i got these tires for cheap to i slap them on and now i got this issue do the rims make a diference if i put them on the front if they were their in the back there all the same right ?

 

I'm guessing you've never ran those 18's before. Those tire sizes are staggered with a 5% difference in rolling diameter. The coupes might even reject those sizes since the stock staggered sizes for the coupe is 2.7% difference. I'm sure the sedan can have some staggered difference but 5% might be too much. It could be what's affecting your ABS, braking and overall...the VDC.

 

My guess is failed vacuum booster....in addition to mismatched tire sizes causing the ABS to fault to to differences in diameter.

For the ABS isssue, put the same size tires on.

For the brake issue, pop your hood and make sure the vacuum line is still on the brake booster. Check to see if the 1-way check valve is seated with a good seal. Wiggle it around and see if it leaks while the engine is running.

With the car off, pump the brake pedal a few times. It should be rock hard. Press down on the brakes, the pedal should barely move. Now start the car. Does the pedal drop a little bit and feel softer? If it doesn't, you have a vacuum booster issue.

Might need to do a little more investigation before replacing the booster.

 

well i ran the 18 before but with all rims having the 245 size tire.. im going to put my 19 back to see if is that can be resolve if not then yeah maibbi it can be my vaccum booster .. ani idea why this will happen ?

 

Def put the other wheels on.


Most manufacturers spec 3-6% as the most difference allowed before the ABS has an issue and faults out.

 

yes 245 on all four should have no problems. And yes, the easiest and cheapest troubleshooting you can do is to put back the 19's. If the problem goes away, you definitely know it's not the ABS or brakes. Plus I highly doubt it's the abs, brakes, or any vacuum according to your situation.

BTW, if the VDC or any check engine light is still on after going back to the 19's, you might have to disconnect and reconnect the battery.

 

well the only time they go on is if i go over 60 or 65 then they go on .. but yeah defently ima do it today cause messing with brake is no joke lol

 

good luck, and keep us updated. I'm sure it's the tire sizes since it started acting up just by swapping wheels and tires. I think you would had better luck if ran 235/45 instead of 235/40 in the front....but don't quote me on that, I don't know too much about staggered sizes on the sedan.

 

lol yeah np .. ima do it on my break .. will have results by end off day.

also i would off never thought by doing this it would cause so much damage as in affecting brake sytem i would think a sensor will just go off but gess not . car is too sensible lol

 

it's not damage or anything, but with the two different tire diameters, it's thinking that one of the wheel is slipping or locking....that's where VDC kicks in. VDC controls ABS and throttle to recover control on the vehicle. In other words...increase or decrease braking power, and increase or decrease throttle(acceleration) until all four wheels are in sync or whatever spec it's trying to achieve.

 

ohh i c.. yeah makes sense . then .. will hope it goes away will let you knw whats up ... thanks dude..