Size of tires screwing up my ABS???

[Elhombre1973]

I've had my Super Swampers on my X for about 5 months now and last week it began sliding forward when I applied the brake slightly. Almost like the brake wasn't catching. I had brake work down about 3 months ago and only had half of it done and I expected that this was due to the other half of the work that had not been done. So I took it to Sears to have the remainder of the work done and they are telling me that either my tires are too big or my ABS system is screwed up. Has anyone had a problem with the size of their tires messing up their brake systems? Please gimme some info. All they reccomended was that I take it to a dealer.

 

[ExplorerDMB]

What size tires are you running? I am currently running 34s and I actually stop pretty well. Better than I thought I would. Your ABS could be going bad, but as long as you are under a 35"/36", you should be alright. I haven't heard anyone have problems with their ABS by just running bigger brakes. I would take a look at the calipers and see how they are. Make sure the rubber around the pistons are in good shape and make sure the stuff is lubed. That's my advice.

-Drew

 

[Alec]

My ABS turned screwy after about 6 months with my 33s.

 

[DeRocha]

My ABS turned screwy after about 6 months with my 33s.

Why would running bigger tires affect your ABS 6 months later? The ABS sensor pressed into the steering knuckle picks up magnetic signals from the exciter ring on the rotor. This tells the ABS computer how fast each wheel is rotating in relation to the others. If one wheel is rotating alot slower than the others during braking the ABS computer will sense the wheel is going to lock up and therefore kicks and and modulates/pumps the brakes. As such I can see the potential for ABS kicking in sooner because of the increased in tire diameter, but I don't believe running larger tires will screw up ABS.

 

[ExplorerDMB]

I am with DeRocha! Still!

 

[Alec]

Yes, I know how ABS works. I'm taking the ASE test next month

I dunno why the delay, but it definately had an effect. I've heard this from many owners of modified vehicles. Even though the sensors basically compare wheel speeds, if the rotational speeds in relation to vehicle speed are out of calibration, the computer may have problems.

 

[sk1er17]

yea, you have to remember that even though you're slowing down at a normal rate, your computer is seeing the truck slow down faster than you feel due to the tire size...

i can see that messing with stuff.. but ive ran 33's for 3 months and my 35's since late august and havent had any problems yet.. fingers crossed though

 

[DeRocha]

Alec - I have read many of your numerous posts and are well aware of your astute knowledge. When I add descriptions on how things work it is not an insult in any way. I add this info for all the members that view the thread and may not understand the process (and don't ask questions).

Back to the question at hand... If you are running larger diameter tires and your ABS works fine for 6 months why do you blame the tires? I could understand if you swapped in larger tires and right away you noticed a problem, but after 6 months I would think the problem lied elsewhere in the ABS system. Accordingly the ABS computer and sensors were getting info from the big tires for 6 months and worked fine. After 6 months the ABS started having problems.. Well the tires didn't change so I would exclude them as a reason you system had problems... I can see that many people that get larger tires are also going to start wheeling harder. This may play a factor in the ABS system starting to have problems.