Tuesday, September 15, 2020

More A4

Today's post gets us that much closer to being done with T's old A4, Nemo. I still have to replace a button and mess with the hood, but after today's post, I am very close.

Before I begin, a couple quick personal notes. First, T is fighting forest fires around Oregon this Summer. If you are not tracking the fires in the news, this is one of the worst fire seasons on record. So, having a son out in it, makes this all the more scary. It makes working on his old car quite surreal, of course, with the air quality this past week, I haven't been working on anything. Second, yesterday was the 1-year anniversary of our dear brother Travis' motorcycle accident. In an odd twist, we just long-term loaned Flash to his niece. We really miss you, Travis. One year later, we think of you every day.

We are living through some strange days, between police behavior, the protests, the violence, the CoViD, the anti-maskers, the widespread fires, recurring power outages and brown-outs, and the lead up to the election, I greatly look forward to some semblance of stability sometime soon. 2020 has been emotionally exhausting; 2021 can't arrive soon enough.

A/C
If you live somewhere hot, having Air Conditioning (A/C) is pretty important. Here in the western side of Oregon, A/C is nice to have, but not as critical for the hot weather. The system's ability to remove moisture from the cabin is much more important. I have lamented this before, but our temperature likes to float around the dew point. This leaves moisture hanging in the air and residing on surfaces. This includes the inside of your car's windows. This moisture is quickly removed by flipping on your air conditioning as your car warms up in the morning. For this reason, I felt it was very important to get the A/C working. All I needed to do was charge it.

The instructions on the A/C charge bottle are fairly accurate. First, get your engine running with the A/C system on full. This is to get the system pressurized. In my case, the air blowing out the vents was quite warm. Under the hood, locate the 2 A/C lines. The thicker one is the lower pressure line, and that's the one you want to work with. Thread off the protective cap, and connect hose from the recharge bottle to the nipple. The gauge should show you current pressure in the system. On the A4, it was negligible. Disconnect the hose from the nipple and shake the bottle. Adjust the target pressure based on ambient temperature by rotating the cover on the gauge. The ambient temperature is on the bottom and the target window is between 2 lines on the pressure-read side of the gauge. Then, re-connect the hose to the nipple, and while shifting the bottle from an upside-down orientation to horizontal, pull the trigger to dispense A/C charge into the system. I counted slowly to ten while holding the trigger and then releasing so I could see how the pressure responded. It took 3 pulls like that to get the pressure into the target pressure zone.

With the engine still running and the A/C still on full blast, check whether the temperature coming out of the vents is any better. In our case, the air was nice and cool. Solved!

Trunk
lid where latch goes
The trunk lid on the A4 used to work. The button on the trunk lid used to open it, and the button on the dash used to work as well. At some point, they stopped. Then, the trunk wouldn't stay closed for a while. T would hit a bump and the trunk would flap open and shut. Most recently, the trunk wouldn't open at all. It was effectively locked shut. Loading your trunk through the rear seats is not really viable. T had purchased a replacement lid from a junk yard, but it was gold, rather than high-gloss black.

We start our efforts by removing the carpeted inner skin of the trunk by crawling into the trunk from the passenger compartment and removing the 10 +/- Phillips head screws holding the skin to the lid. There are 2 hiding in the pull handle. Once all are removed, the panel will flop down, exposing the latch. Using a screwdriver to save my fingers, I pushed against the latch workings to get the lid to pop.

old on top
Once open, we can see what's what. It appears that there are 2 styles of latch mechanism on these trunks. The one on Nemo lacks a key-lock. The latch on the donor has one. The part that actually latches, however, is pretty much the same. And, that is the part that was not operating correctly on Nemo. The button under the dash didn't work regardless, and the button on the trunk still doesn't work, but it was the latch that was the real problem. The latch is held to the lid with 2 13mm nuts, and is activated by a lever which moves the mechanism from right to left to unlatch. In the upper picture on the right, here, you can see it's rusty end protruding from the left in the little hole. I discovered that the actual mechanisms are slightly different beyond the key / no-key difference. The point at which the lever attaches to the mechanism is not in the exact same place, so I had to re-locate the activation motor about 15mm to the left in order for the latch, when at rest, to remain closed, and open when activated.

Since the activation motor had been mounted with bolts threaded through mounting holes in the trunk, I felt uncomfortable just boring holes. Instead, I set the bolts aside and used cable-ties to set the activator in the right spot. I threaded on the replacement latch mechanism, connected the lever and set the motor. Once the cable-ties were taut, I confirmed the activation of the latch by jumping across the wires that connect to the broken-and-removed trunk switch on the dash. Several tests were followed by multiple trunk closing/opening trials before I was convinced that I had it right. I decided to leave the cable ties in-place because the right-hand bolt hole for the activation motor was over a natural hole/gap in the trunk so I couldn't effectively mount it with the old fasteners. The right edge of the hole is visible on the left edge of  that upper picture. The cable-ties should hold for a good long time as-is, even if it does feel a little janky. With the inner skin back in place, you can't see the new latch or the janky-installed activation motor, so it's all good. And, it works. I just need to replace the button on the dash. I'd like to get the button on the trunk lid to work, but there is some mystery wiring in there, and getting to that button is fairly difficult. It is possible that it is shut-out because of some lock somewhere that I haven't been able to find. German engineering strikes again.

Hood
trunk card
The hood on Nemo is the last big visual issue I wanted to improve. This is T's second A4, so I can't remember if we replaced this hood or if it was on his old one. Regardless, this hood was painted with what looks like black primer. There was no sheen. None. The rest of the car is a high-gloss black color, so the hood didn't look that great. Additionally, the front grill was also painted flat black, but over the course of many miles of driving, some of the paint had chipped, both on the grill and on the nose of he hood. It looked bad. So, off to the parts store I go to get some paint. The card in the trunk says the paint code is LY9B. The duplicolor paint-match sheet didn't have a reference to that paint code, so I got the one they DID have for black.

The hood removed very easily. The hood stand is held on with a little C-clip, and then the little post slides out. I set my tool box on the engine intake to hold the hood up, and then removed the front 2 bolts from the hinge (13mm). I loosened the rear ones before carefully removing them all the way with my fingers so I could keep control of the hood when the last bolt gave. It surprisingly didn't shift around. I moved it to a pair of sawhorses on the lawn, and proceeded to sand it with 250-grit sandpaper. I got all of the weird anomalies off, and then washed it to get all of the dust off. I felt ready to paint.

I blew 2 cans onto that hood, but the color just didn't get as dark, nor as shiny as I expected. Audi offered 2 colors of black, and the one I needed was a super-deep super-shiny black. The one I got, however, was more of a dark charcoal and sort of satin finished. I will need to paint it again, with a different, blacker, paint. Before I repaint it, I will play around with 1000 grit sandpaper and maybe a buffer to see if I can get this paint to look decent. I figure this is an opportunity to practice buffing new paint, so I will take the opportunity before painting over it. Who knows? Maybe I can get the it looking good enough that I don't re-paint it... but I doubt it. Currently, it looks like a carbon-fiber hood, which might work for some, but not most, drivers.

I think that's it for today. If the sanding buffing experiment becomes a thing, I'll post on it. Otherwise, I will probably be reverting to the Zed (1979 280ZX) after I have Nemo's hood installed. As we move deeper into September, I am feeling the pressure to get the body-filler spread and sanded. Wet season is coming! Thanks, as always, for following along.

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