Brake materials and biasing
 

I did a search but didnt see this on any of them.

I just cleaned the wheels on my 07 EB EL w/18" and scorpions. I have some questions based on my observations of the wheel brake dust and the appearance that the rear wheels had more dust than the fronts.

First, are the pads (F & R) of the same material? (other than different sizes). If so, it appears that the biasing is toward rear application before the fronts, which is counter to what I have seen (almost all my life anyway!). I would have expected the biasing would apply the fronts before the rears, therefore, the fronts would have more dust. Is there any info on the biasing?

I saw some posts on where to get good pads and not to use slotted, drilled rotors. My expy is driven easy, so I have seen no issues with pulling or warped rotors. Still dont like the way it steers, even after FMC alignment (an earlier post).

the Expy and F-150 share the same platform...and at least 75% or better of the parts interchange


I know that doesn't exactly answer your question, but it's a bit of an explanation.



also, does your Expy employ the RSC on your pretty often?

No, I am not an agressive driver, at least in this rig :). Mileage seems to be greatly affected by that and significant driving before engine is completely warmed up. Wish I could control/lower the temp that the processor (PCM) uses to come off the cold start mixture. Down here in Fla, there is almost no such thing as a "cold start"!

Guess I better become more familiar with the operation of the RSC. I dont think it deploys much if at all, but then I really havnt paid attention. So far, mostly the wife drives it (grandkids etc) and she almost has me screaming---you know, left lane, slowpoke, oblivious, and unaware of those things called rear view mirrors :-banghead.

I know about the function of the TC and the basic RSC operation, but need to read up on how to tell if it is testing or deployed. That would certainly screw up any normal F/R biasing. If it werent for the dash lights, I would disable the TC, because 99% of the time it is of no use. I have driven many old clunkers w/o LS and in many conditions without problems. I realize this is a 6K plus vehicle that was not designed to do 100G's around the cones-----a lot dont :rolleyes:

TX

I absolutely hate my RSC...but I'm a bit of an aggressive driver. The traction control is just dangerous IMO.

I was on gravel the other day...that was very scary when it engaged.

Tc
 

I dont recall seeing the effect of a non-locking limited slip device in the rear end. I am thinking of a true-trac, Gleason, or Alburn type (provided they make them for the 9.75). If there is no slippage by one side or the other, then the TC function would not apply. It deploys (or activates) when one rear wheel sensor detects a differential in wheel speed. There has to be enough leeway to allow for a tight turn without activating. I just dont see where a limited slip would hurt or have anything to do with the TC, except to render it useless.

I dont really see where a limited slip would negatively affect the RSC function either. From what I understand about the RSC, it applies braking to counteract unusual swaying. Both the TC and RSC presumeably work under a coast condition. Even if under power, the RSC will automatically cut the throttle an remove power application (Thats my understanding of it anyway---where am I wrong?). From what I know of limited slips (maybe even full lockers) they are not applied under coast conditions. The TC is the only only thing that applies under a loaded condition.

The point of all this is that if TC and RSC cause abnormal brake wear on the rear pads, why not take away some of the function but preserve the safety aspect.

O.K. somebody where am I wrong in my thinking :confused:

your reasoning seems sound to me


I've also experienced the RSC cut in when I took a corner a bit hard and was on the throttle...it was very similar to when you hit the speed limiter







here is another thought. have you towed a fairly heavy trailer lately...or had alot of weight in the back? that would pull the front up slightly, and make the rears do more braking

I have towed a lot of pretty heavy stuff with other vehicles, nothing with this one. I understand towing a load, but then that's what the trailer brakes are for. Maybe a pick-em-up could use more rear biasing, but not a "station wagon". I suppose you could have a load in back, but not likely to have a ton or so of fertilizer in 100# bags! None of the grandkids are that fat--yet.

Short of someone who knows chiming in, I dont know of any way to test or prove if the rear brakes are applied too early or too much. Still would like some more input about how a limited slip would affect the TC, if at all.

BTW sorry to read about your paint problems, my 93 bronco has the paint problem of the clearcoat and basecoat flaking off. The primer sticks really well----my hood is entirely "grey" and other areas have cracked paint. It would require an entire paint job. If I fix a bronco, its going to be the 72 that belonged to my brother.

As far as brake pad material goes, I'de be willing to be the factory pads, noth front and rear, are the same manufacture and same material. I've never seen a factory set with different materials from front to rear.

If you regularly carry passengers in the middle and/or rear seat 3 rd rows, you going to get more braking out of the rear due to the proportioning valve allowing more pressure to activate the rear brakes. I would also think that the Expy's rear bias would be different than the F-150 due to the fact that the Expy carrys more of it's weight over the rear tires. The bias *should* be different if for no other reason than that one. More weight, more braking power needed to slow it.

With just about any semi-mettalic pad you're going to get some brake dust. Check out EBC brakes online and take a gander at their different selections of pad materials. EBC is probably one of the better known brands of replacement pads that offer different levels of dusting and performance levels as opposed to the factory pad.

EBC Brakes - Brakes for Cars, Motorcycles, Trucks and SUV