12-08-2012, 08:45 PM #1
First time under the car (CDV Mod)
Let me preface this post by saying that I have zero experience with maintaining a car other than putting gas in it, getting the oil changed, and replacing wiper blades. I've been lurking here and posting sporadically for the last few months and I've learned a ton about my car. However, putting knowledge to work is another thing entirely! This is my experience doing a fairly basic mod and a quick review of it for those who may not have done this yet.
I drive a 6MT and the jerky 1-2 shift has bugged me the entire time I've had the car. It wasn't long before I learned about the CDV, it's function, and how to get rid of it. This weekend I took the plunge and popped my wrench-turning cherry.
Getting the car up and locating the CDV proved simple enough (removing the under-body is a $#@!ing chore though...). Unplugged the old CDV, let the fluid drain out of the flexible hose, and plugged in the modded CDV. Then it was time to bleed the clutch.
This is where I started to have problems. I had my buddy working the clutch while I was under the car attempting to open and close the bleed screw. Long story short, we went probably 50+ open-close cycles with nothing but air puffs coming out of the bleed screw and a limp clutch pedal. I, the expert mechanic, didn't know what to expect as this was my first time bleeding a clutch, so we just kept trying to make it work. There was fluid in the reservoir so it should come down the line eventually if we keep bleeding it, right?
It started to get too dark to keep going and both my rechargeable batteries for the light were dying. So we called it quits for the night and shut her down, not knowing what we were doing wrong. I spent the evening combing the internet for clutch bleeding DIYs, techniques, and troubleshooting info.
I stumbled on a thread at m3post where a guy was having a similar problem. It turns out that the brake fluid reservoir in E9X cars has a partition in it and that the clutch master cylinder pulls fluid from the other side of the partition. It also turns out that there is not much fluid held in the partition and that you have to fill the reservoir up to nearly the maximum to get the fluid in there. So I had just been pumping air through the system.
The next day, I fill the reservoir up to the brim, start the normal 2-man bleed technique over and hope for the best. I had my buddy check the reservoir height after 2 or 3 open-close cycles to make sure the clutch partition was getting fluid in it and not running dry, he had to top it off a couple times, but otherwise it went about as smoothly as I could have hoped.
The clutch had a little play in it at first after we wrapped up the job (not quite as hard as it was before), but after driving around for a while then letting the car sit, it feels just like it used to.
The 1-2 shift is vastly improved and the other shifts are far more predictable, hardly any jerky feeling (unless you screw up the shift). Rev matching on downshifts is easier. For anyone who isn't just learning how to drive a stick, this mod is necessary.
TL;DR: I wanted to do a CDV swap. Couldn't get the clutch to bleed. Did research and figured out what was wrong. Fixed the problem myself. Car drives great now.
12-09-2012, 12:02 AM #2
I like the TLDR part
Congratz on getting your car going and making an improvement and starting to work on your own car!
12-09-2012, 02:06 AM #3
12-10-2012, 08:49 AM #4