I tried this in the "brake section" for repairs and no one seemed to have a answer, so I thought I'd try here and see if I could get a response. Does anyone know if there is a brake bias adjustment, or proportioning valve for the brakes, on our Crossfire's? If there is, could you let me know where it is and how it's adjusted. I scoured the forum and my Chrysler Crossfire repair manuals, but could not find anything. If there is none, has anyone installed an aftermarket or GM style proportioning valve in the Crossfire's brake system? I feel that the front brakes are doing all the work and the rears are just polishing the rotors. Just my opinion. Would love to hear some pertinent comment.

Thanks,

Jim

 

ELECTRONIC BRAKE PROPORTIONING

Electronic brake proportioning (also called Electronic Brake Distribution or EBD) was introduced a number of years ago, and is now becoming common on many late model import and domestic vehicles. Some applications include late model Honda, Toyota, Audi, Mercedes and others. The Honda Accord was equipped with electronic brake proportioning in 2006, and all Honda vehicles, except the S2000, now have it.

With electronic brake proportioning, pressure from the master cylinder is routed equally to the front and rear brakes. There is no mechanical proportioning valve in the brake system. Instead, the Antilock Brake System (ABS) controls what happens at the rear brakes.

The ABS system monitors the speed of the rear wheels via the wheel speed sensors (WSS) when braking. As long as the rear wheels are slowing at the same rate as the ones up front, and there is no indication that the rear brakes are locking up, full braking force is applied to the rear wheels. With the rear brakes now doing 50% of the work (instead of 20 to 40%), the vehicle stops quicker and in less distance.

On the other hand, if the rear wheels are starting to lock up because the vehicle is braking hard on a wet or slick surface, or because the rear wheels are lightly loaded, the ABS system intervenes to reduce pressure to the rear wheels. This is done by closing solenoids in the ABS hydraulic unit that isolate the rear brake circuits. Other solenoids are then opened to release pressure from those circuits. The solenoids are then repositioned so pressure can be reapplied to the rear brakes.

 

as they say google is your friend

 

Google and I, we be mates as Crocodile Dundee would say

 

ala_xfire - Thanks for the information. It sounds like there is a lot of electronic action going on in a very split second. Hope it all works as it should. Being a very senior citizen, I don't like having to depend on all this electronic "stuff" to protect me. I guess I have no recourse but to accept it. Reminds me of the TV programs that try to explain why a plane crashed because there was a computer problem when the pilot tried to fly the plane. I guess this stuff works since it's on just about every car now. I hope we don't have to find out the hard way when there is a problem. Considering how the Crossfire has so many electronic "gliches" with systems being intertwined, I hope we all don't meet the rear end of a tractor-trailer truck.

Anyway, thank you very much for your searching and explanation. That answer's my question.

Jim

 

I'm with you 100% on your remarks about the confusers running the modern cars.
One of the first things I did when I got mine was find an empty road, run 60 and lock the brakes up to see if that anti-lock stuff really works.
It did, make sure your shoulder belt is tight before trying it or you'll be picking your teeth out of the steering wheel - if you have any left at your (our) advanced age.

 

Proportioning is also affected by the difference between the surface areas of the front and rear brake cylinders. The difference between the piston areas on the front and the back will affect the pressure applied and the difference between the front and rear pad surface area will affect the friction to some degree.
The front or the rear brakes come on a fraction before the others, I forget which.

 

Thanks, Guy's. I'll just keep it at a sensible speed and on paved roads to be safe. It's interesting what 180 said about the different surface area of the brake cylinders (I presume the brake calipers). Mine are stock XF calipers and the pads were from Needswings as a set for front and rear. They are ceramics and seem to be working as they should. The rotors are new also. I was hoping there was a way to make the rear brakes do just a little more work than it seems like they are doing. I'll just have to live with it and hope the electronic "stuff" keeps doing what it's supposed to do.

Jim