I have a 2009 Lancer GTS CVT (sun and sound package) with only 40K miles on it, I am the original owner. The dealer replaced the CVT transmission back in October of 2014 because it was making a weird noise. So, here is a list of problems that I am trying to find solutions to. I only have the powertrain warranty now, so if any of this is covered under that, let me know.

Stiff Brake Pedal: I checked my brakes last year and they still had a good 60% on the pads. Well, right now my brakes are stiff and they have little pedal play in them. I remember when the vehicle was new that I could press the pedal almost to the floor. Now, it's so stiff, I have maybe an inch or two of travel at the most. This is certainly not how it should be. It stops fine though. What could be the problem? Do I need to bleed the brakes? (Havent done that yet, cause havent changed the brakes.)

Vibration: The car vibrates when I am stopped at a light and in Drive. Putting it in Neutral does reduce the vibration significantly. It gets even worse when the AC is on. I feel it the most in the brake pedal, it's insanely annoying. When they replaced the transmission, could they have not tightened something? I do have a 2.4L Takeda Intake, but no other mods. I even hear a faint jackhammer type noise from the engine bay, but you can only hear it sitting in the car and if the AC is on.

Headlights Dim: When the vehicle is stopped, my headlights dim if I use the windows or sunroof. I know the alternator is not outputting as much power at lower RPMs, but I don't recall this happening in the past. I have a new battery that's only 6 months old. Is this a bad ground?

Hissing In Speakers: I have an aftermarket sound system. I use a JBL MS8 sound processor to interface with the factory amplifier to get a signal from it. The MS8 has two amps connected to it that power the speakers and a sub. The hissing volume remains constant no matter what the headunit volume is at. The hissing only goes down if I change the MS8 volume, but then it becomes too quiet. Any idea on how to get rid of it? It does change in pitch with the alternator and sounds like a jet engine. My ground is located in the trunk, connected to shiney metal on the left pillar by the wheel.
SIDE NOTE: Can I pull a signal from the back of the factory nav unit, instead of connecting to the factory amp outputs? I think it would be a cleaner signal.

Any help with any of these issues would be GREATLY appreciated. Now that 9glancers is down, I am having a hard time finding a forum that is actually being used with active members. THANK YOU!

 

1. The brakes. Your brake booster vacuum is not working. Inspect the vacuum line for hissing/connection. Remove the line at the brake booster assembly with the engine running. It should have a strong suction. If it does - the brake booster is bad. Since the transmission was removed - my money says they didn't reconnect it properly...

2. Headlights dim. Check the battery-to-body ground wire. This may also solve the amp hissing (bad ground).

3. Amp issue. No, you can't RCA low level output directly from the OEM head unit. Try unplugging the RCA inputs into the amp. Does the hissing stop? The alternator whine stop? If so - there are RCA noise filters available (partsexpress.com). If not - get a noise filter for the power wire at the amp. Where did you get the 12VDC power for the amp? Directly from the battery? If not - this may be a source of your noise as well...

 

I can't thank you enough for the help and quick response!! It is much appreciated.

I went to my car while it was off, pumped the brakes until they were rock hard, and turned the car on. The brake pedal did move a few inches down. Does this mean the booster might be ok? A quick search puts the booster at about $500 and so I wouldn't mind avoiding that hah. Thankfully, I can do the labor myself. I'll pull the hose off that goes to the manifold in a day or two and check that. Because of my Takeda Intake, the hose currently is just floating, being supported by a plastic zip tie, because it doesn't have the clip that the original intake has on it. Idk if this is a problem or not.

The JBL MS8 is designed to integrate with factory sound systems by tapping into the speaker wires. Currently, it taps into the output of the factory amp. Does the stock Navi unit not have its own speaker outputs, which at the moment are not used because the factory amp is connected? Maybe I am misinformed haha.

The JBL MS8 and both amplifiers get power directly from the battery (using a distribution block in the trunk), which runs along the passenger side of the car. I removed the RCA cables from the amp, and the hissing was still there. The JBL MS8 has its own built-in amplifier, so it is powering the two rear speakers, while a separate amp is powering the front speakers. The MS8 is providing an RCA signal to that separate amp. The power wire is 4AWG connected right to the battery. Do they have a 4 AWG noise filter for power wire, or should I buy a capacitor to put in-line instead?

 

Yeah, check for a strong vacuum at the hose. What had you done/installed/modded when the problem first appeared?

Yep, sounds like a weak brake booster. It can leak internally. Do you hear any hissing with engine running? How about if some one hits the brakes/pumps them? Does the engine bog down (indicating massive vacuum leak)?

Bleeding the brakes is only for a 'soft pedal'.