I didnt read it all but bleed your master cylinder

 

I've actually swapped the master cylinder out at this point in trying to figure out where the problem is originating. nothing changed.

I'm definitely considering this, but I was hoping someone (or multiple people) could confirm whether or not bleeding with the engine running is just for dealers to be able to cycle the ABS unit. I'm guessing most of the people on this board bleed with the engine off with good results, but maybe I'm wrong.

 

As a last resort, you could ask a dealer to bleed it for you.

 

Yes I read that but did you bleed it just like you would the brakes but just crack open one of the lines on it. Any time I completely empty the brake system of fluid I will do this. Also bleed the abs system. You may need a Modus for this ig you can do it by making violent stops.

 

just wanted to update since it's been a while and this is still ongoing. since my last post I've bled with the engine running, replaced the front calipers, replaced the ABS unit, and replaced the rear calipers. no change after any of those. I've now changed every component in the brake system from the master cylinder out except for the hardlines. literally everything: master cylinder, ABS unit, calipers, rotors, pads, fluid, tires. every caliper bleeds fine, so I'm really at a loss for what would cause the brakes to lock up so early - well before the grip limit of pretty much any street tire.

 

Just saying.......

There is no proportioning valve that I am aware of. The pressure to each caliper is controlled by ABS with inputs from the steering angle sensor and the G-sensor under the console.

 

I think the proportioning is inside the ABS block.

I agree that the ABS unit can control the pressure to each wheel, but not when the ABS is disabled (by pulling the fuse). In that case, I would think the front/rear brake bias would be set based on the internal geometry of the ABS manifold and couldn't be varied. I know people run their cars all the time with the ABS fuse pulled, but I've never heard of someone reporting a problem or any sort of similar brake issue like I've been having.

Does anyone have a more specific location of the steering wheel sensor or g-sensor? I might try poking around those areas just in case.

 

According to the manual the rear front balance is maintained electrically. In the event of a complete failure of the system (or fuse pulled) I imagine the brakes have to still work in some safe manner. The ABS section in the shop manual is 126 pages long so maybe the answer of how this happens is in there. However it is more than I care to consume tonight.

A quick glance shows the g-sensors (2) in the area of the parking brake handle and the steering sensor behind the steering wheel.

Anyway, it appears, when the ABS is active, it is controlling pressure to all four calipers individually. This is a mighty fine system with the ability to help the car corner. But with any complicated system it would appear trouble shooting could be difficult.

I did note a warning about not dropping a G-sensor if removed from the car. Dropping it will break it. So, you gotta wonder how they ship you a new one.

 

Sooo, any updates? Seems like you sold some other Evo since then, do you still have this car?

I have the same symptoms and I really don't want to replace everything that you did and have nothing to show for it.