Parking brake cable replacement, turbo oil leak, heater valve function with a/c...

[Kenneth]

I have a number of issues that I'm working through on my 200q20v.  Please let me know if you have any comments that can help me sort through any of these little projects.  Here's two of them:

1.  Parking brake cables:  I just replaced the rear calipers with rebuilt ones, and have found that my parking brake cables are in bad shape.  They bind and the sheaths are broken where they attach to the rear subframe.  I see replacements on Amazon, but I'm wondering if there are any writeups or BTDT's online about replacing them.

2.  Oil leak at turbo supply line:  I recently installed an RS2 EM and turbo.  I have had some challenges with the turbo part of it, and currently I have recurring oil leaks at the upper oil line.  I put a fresh gasket on it but when I start the car, oil will show up around the upper line flange, and around the joint between the compressor backing plate and center housing.  I just had the turbo professionally rebuilt, so the seals/o-rings are new.  (I had the brand new-old-stock turbo rebuilt because when I first installed it it was leaking oil through the seals, because I made the mistake years ago of having the complete and assembled turbo cryo-treated, which embrittles and cracks anything rubber/plastic.)

I had to do some clocking to get the center housing lined up with the lines, and I also did some clocking of the compressor to move it out of the way to get access to the flange bolts and attaching the lines, etc.  I'm pretty sure the leak is at the flange for the oil line and not at the turbo's o-ring seal, but it's possible if I did something wrong with the compressor clocking I did.  Perhaps the o-ring was binding up when I rotated it, is one thought.

I have two potential causes for the oil leaking that I intend to explore.  One is that the center housing isn't clocked exactly correct and I'm not getting good and flat contact between the oil line flange and the mating surface (the theory I think is most likely).  The other is that maybe there is some obstruction in the return line that is causing the oil pressure in the turbo to spike and overcome the gasket or seals (someone else suggested this as a possibility, but I doubt it).

I believe the paper gaskets for the oil line flanges are supposed to be put on dry, without any RTV or anything, right?

I'm cinching down the upper flange nuts pretty tight, but I'm not using a torque wrench, so is it possible that I'm overtightening them?  I doubt that I'm undertightening them.

Are the o-ring seals very delicate?  Could I have damaged them by unevenly loosening the backing plate bolts and forcing the rotation of the compressor when certain areas were too tight?  I don't think I did that, but I also thought the had the oil line mated up well with the center housing, so I'm questioning all of it.

3.  This one may not be a problem, but I noticed my heater valve doesn't close when I run the a/c.  Is that functioning correctly?  I would have thought that in addition to the heater box flap closing off the path parts the heater core, that the heater valve would close if I'm not running the heater.  I pulled vacuum on the heater valve and it does close, but I haven't seen it close from running the a/c.

As for relative successes, last night I got my climate control working.  I added the recirc flap servo repair bracket, replaced a cracked up vacuum hose, added a new return spring, and plugged in the harness for the climate control box that probably controls the heater core flap, which I must have left unplugged years ago when I did the heater core and blower motor.  

I also found that with the repair bracket, installed, the fitted recirc servo was further away from the plastic bridge than before, resulting in the upper recirc door not fully closing because the servo would bottom out before it would seal.  I'm not sure if I was supposed to trim away from of the plastic bridge onto which the repair bracket attaches, but I would suspect not because it would make it weaker.  

I ended up putting some rather thick generic foam weatherstripping tape around the upper door to fill in the gap, but it's not sticking very well even though I stripped all the old foam and adhesive with carb and brake cleaner.  The next thing I want to do for that is use some glue to supplement the weak adhesive that came on the foam weatherstripping.

Thanks,

Kenneth