Several people were very complimentary about my achievements last weekend with the Mercedes 300D, but I have to be clear:  most of the achievement was Pierre’s.  I worked, but mostly I was there to learn while Pierre busted his knuckles doing the hard stuff, so I can’t take credit for most of it.

Today’s minor adventure in old car repair will demonstrate the true nature of my mechanical abilities.  As you may recall, we discovered a few minor needs toward the end of the weekend, for which we either lacked the proper tool or a Mercedes-only part.  I ordered a few things on Monday and they arrived today.  There were really only three tasks:

1. replace a bad relay, one which controls the electric auxiliary engine fan.
2. install a rebuilt kit in the mono valve. This is a fancy name for a simple valve that opens up to allow hot engine coolant to circulate in the heater core, thus providing heat to the cabin.  It has a rubber diaphragm that breaks eventually.
3. replace one bad glow plug.  The glow plug warms the engine cylinders on a diesel, so that you can start it.

The relay was simple.  No tools involved.  You open a plastic cover, pull up the old relay, plug in the new one. Anyone who can change a light bulb can do this, so not surprisingly I managed to achieve it.

Then, buoyed by my success so far, I unbolted the mono valve and opened it up to reveal the internal plunger.  But I forgot that the engine was still warm from driving it 30 minutes earlier, so when I pulled the plunger out, coolant spewed all over.  Whoops! I quickly thrust the plunger back in.  Emma was standing by and got splattered, but fortunately it was not hot enough to burn.  That made me feel really stupid.

So I set that task aside and switched over to replacing the #3 glow plug.  I had a hell of a time getting to it.  You know how things that look simple often aren’t.  This happens to me a lot.  All you have to do here is unscrew an 8mm nut to remove the electrical connection, then unscrew the glow plug.  But I couldn’t do it.  The tools I had just wouldn’t fit in the space due to obstacles like the injector lines and injection fuel pump.

It was looking like I’d have to start removing injection lines, which would have brought the repair up to a new level of messiness and difficulty.  Instead, I finally managed to get the electrical wire and the glow plug by using a U-joint and a long extension on the ratchet wrench, and wrestling with it for a while.  It was frustrating because it seemed like it should be easy.  I dropped a nut three times trying to re-thread it, and once it fell into a spot beneath the injection pump where I thought I might have lost it.  Eventually the job got done, taking about three times longer than I had expected.

But in the process I made myself a new job.  I didn’t realize it, but I was leaning on the brake booster (vacuum) hose when I was fighting to get the glow plug electrical connection back on, and SNAP! a plastic vacuum fitting on the hose broke off.  This fitting goes to various transmission and engine accessories.  The brake booster is still getting vacuum, and I can plug the open fitting, but the transmission won’t shift right without vacuum, and the fitting can’t be glued back.  The hose was probably fairly old and brittle.

I could try to seal it up temporarily with some silicone tape, but why bother? The part has to be replaced anyway.  I sent the picture to Pierre and he confirmed that I need to buy an entirely new assembly, which includes the plastic fittings, vinyl hose, and metal ends.  The part comes only from Mercedes and it has to be ordered, so I’m lucky to wait only until Monday to get it.   Of course, installing it appears to be just a matter of two easily accessed nuts and two other vacuum hose connections.  I think I can do that without breaking anything else.

When the glow plug was done I went back to the mono valve.  Things were cooled down now, so it was fairly straightforward.  As expected the diaphragm was gone.  But unexpectedly, I found several 6-legged bug corpses inside the cylinder.  I’m not sure how they got in there, or why.  I cleaned them out and the rest was straightforward. Total elapsed time: about an hour.

So that’s the real glory of this type of project:  cleaning bug corpses, cursing at difficult nuts, and wearing Eau de Coolant.  With each step I feel like I’m learning, and simultaneously that I’m incredibly incompetent.  This kind of stuff isn’t easy for me, but in the end I do enjoy the sense of accomplishment and the gratification that comes from achieving something you’re not naturally good at.  So if you have any congratulations for me, let them be for having tried.  Turns out, that’s the hard part.

We started on Sunday morning at 7:15 a.m. with a sense of optimism, or at least I did.  Despite being the coldest day of the three we had spent working on the old Mercedes 300D, I was feeling good about the project because our list was down to a manageable few remaining tasks.

Pierre, on the other hand, was still feeling some slight trepidation about the O-ring problem from the night before.  Although he had checked carefully to ensure that the substitute O-rings would fit, he wasn’t going to feel right about it until the part was installed.  They were a little tighter than the correct part, which made Pierre’s job hard, but it worked out fine and by 8 a.m. or so the turbocharger drain was back together.  I’ve heard of guys taking an entire weekend to do this one job because it’s not easy under the best of circumstances, so as far as I was concerned Pierre did well under fire.

We kept putting out metal bits on the curb, and inevitably someone with a pickup truck would swing by and grab them.  I put out an old radiator, four shock absorbers, and dead engine mounts, and they disappeared so quickly that I had to be careful about the metal parts we intended to retain.  When I put items I had cleaned on the driveway in a sunny spot to dry, I kept an eye on them.

The hardest jobs had been tackled on Friday and Saturday, so all we had left was fairly minor stuff.  Still, it got messy with dripping fluids, and I was busy keeping up with it all.  I did want the carport to be somewhat better than a toxic waste dump after everything was done.  All the used fluids got collected in big seal-able containers and returned to the auto parts store for proper disposal, and after recycling all of the cardboard, paper, and plastic I was pleased to see that we generated less than a barrel of waste.

By noon it was clear that we were in the home stretch.  The messy transmission service was done, we’d replaced the oil and filter (even though I did it just 200 miles ago; Pierre wanted to give the engine a chance to clean up after some neglect by the prior owner), front shock absorbers, and transmission shift bushings.  So we were able to relax and do some tweaks to the vacuum system, adjust the hood so it closed better, and little stuff like that, before putting the wheels back on and lowering the car down to the ground.

At 1:00 p.m. we were done, and out on a test drive.  Amazingly after all this service, we found only two problems.  There was a loud deep rattle from the right side, which turned out to be a loose caliper.  No big deal although it sounded horrible—just tighten two bolts.  And strangely, the steering wheel was now upside down when the car was going straight.

This second problem confused us a little because Pierre had been scrupulous to follow the factory technique and use the correct factory specialty tools to install the new steering gearbox, but we decided to have a celebratory lunch anyway.  Part of Pierre’s goal this week was to eat well, so every day I took him to a different ethnic restaurant for lunch (Mexican, Indian, Vietnamese) and in the evenings Eleanor cooked up fabulous and enormous dinners.  We worked long days in cold weather but I think we both may have gained weight.

In the end, we worked for only 24.25 hours.  That’s under the budget of 30 hours I had set, which helps with the overall cost. I’m pretty sure the billable time for all this work at a shop would have been at least double.  And it’s nice to wrap up such an intense project with time to spare.  We had time to take the 300D out for a scenic drive around Saguaro National Park, and time afterward to tweak a few things just a little bit more.

Pierre wanted my car to run perfectly, and I can say that he hit the mark.  It still bears the patina of an old car on the outside, but mechanically it’s just about perfect.  I’ve got just a few things to take care of myself, all simple stuff, like a glow plug, a relay, monovalve rebuild, and the rear differential fluid change—things we skipped only because we didn’t have everything we needed for those jobs.

This morning I had to drag myself out of bed at 6:15 for one last task.  We wanted to get the car to the local dealer for an alignment by 7 a.m., so that the odd steering wheel issues could be resolved before Pierre had to head home.   The issue turned out to be simple (the Pitman arm was off by 3 splines, for those of you that know what a Pitman arm is), and the car did need an alignment, and at last we were done.  We collected Pierre’s tools, made one last tiny adjustment to the vacuum modulator, and then he was gone.

This project is still not over, but it’s about 95% done.  When the weather warms back up this week I’ll finish the last seat and when I get the parts I need I’ll do those last few jobs.  Tires are next, and after that we’re ready for a road-trip.  Soon I’ll be looking at the open road through the three-pointed star, while the old-school diesel propels me with the sound of a well-oiled sewing machine.

But that’s not all the satisfaction of this project.  I’ve learned so much.  I can keep it running by myself.  Having taking much of it apart, or at least observed it being taken apart, I have an appreciation for the great engineering that went into the car.  It has fewer mysteries about it now.  Unlike other cars I’ve owned, I feel like I am in control of the man-machine relationship, rather than being a hapless of victim of whatever error message a computerized car might throw up.  I’m not really worried about having a car that will run on scavenged vegetable oil after EMPs destroy all modern cars during a worldwide apocalypse.  I just like having a machine that I understand, and I’m glad I made the effort to get into this project.

Before Pierre arrived, he jokingly said that his visit would be “the worst three days of your life.”  (He didn’t know that I’ve been going to Louisville in December for RVIA for eight years.)  He threatened ten hour days, lots of grime, and him barking orders at me all day long.

Ho-hum.  If that’s the worst he threw at me it would be a cakewalk.  And indeed it was on Friday.  I spent much of my time scrubbing decades of grime off old parts in a tub full of black greasy water, I kept the carport organized, hauled trash, handed Pierre tools, and cleaned up spills.  It was kind of like being a dishwasher in a busy restaurant, only things were dirtier.  So this was no big deal.

On Saturday things got a little more challenging.  We are having what is described in Tucson as a “stormy weekend,” meaning that the temperatures plummeted to the 40s overnight, and we had light & scattered rain showers for a few hours in the morning.  Not too bad considering what’s happening in other parts of the country, and it was just enough for me to switch to long pants, a sweatshirt, and a wool cap until things warmed up.  We started promptly at 7 a.m., while the sky was still gray and dim, and plunged right into it—literally.  I can say with certainty, there’s nothing like cleaning brake parts with a toothbrush in cold black water at 8 a.m.

I was chilly, but Pierre was in his element.  Relentlessly cheery, this 6 foot-4 inch dude wedged himself under the car on the bare concrete and happily spent the morning hammering away at reluctant suspension parts.  He replaced the ball joints, the brake rotors, re-packed the wheelbearings, the flexible brake lines, and the often-overlooked “brake sensor harness cables.”  Occasionally he put me on something easy like installing the new brake pads.

Around 9:30 we were joined by Nicholas, a fellow 300D owner who I had met through an online Benz forum. This led to the highlight of the day for us, when Pierre taught us how to adjust the valves on the engine.  Nicholas and I took turns getting the feel of each valve.  I had a really hard time with this, because it’s hard for me to get my head around spatial orientation things sometimes.  Once I could visualize the setup of tappet-nut-nut-spring, it got a lot easier.  We felt good enough about our skills by the end that Nicholas and I vowed to get together later and do the valve adjustment on Nicholas’s 300D without our benevolent teacher to bail us out.

Even though I’ve griped about the weather, we couldn’t have picked a better time to do this job.  A week ago we would have been sweating in 95 degree afternoons.  For this kind of work, it’s nicer to have to wear a cap for a few hours until things warm up, than to be dripping sweat all day.  And of course, being Tucson, it was sunny and pleasant for the rest of the afternoon.

Another bit of good timing: Monday is our local semi-annual “brush & bulky” trash pickup day, when the city comes around to pick up almost anything that won’t fit in a regular trash barrel.  Everyone piles up all their stuff on the curbside, and then in the days before the official pickup, guys in beat-up old pickup trucks cruise the neighborhoods looking for free stuff.  Some of them pick up old furniture for their homes, others collect scrap metal, still other seem to be looking for overlooked treasures to bring to “Antiques Roadshow.”   (Good luck with that.)  So getting rid of a radiator, four rusty brake rotors, and a water pump was easy as pie.  I piled it all on the curb and it was gone a few hours later.  Nicholas took the air conditioning compressor, as it was still working and his doesn’t.

I estimated that in this three-day automotive orgy plus the month of work I’ve done already, we’d be resolving about two years worth of sorting-out tasks. Normally you pace yourself when sorting out a car, because it’s expensive and because it takes a while to figure everything out.  This approach with Pierre is unusual but I think it makes sense for a car that is basically sound, and an owner who wants to be intimately involved in the process.  The downside of doing it all in three days is that one little glitch can really screw up the plan. That’s the thing I’ve been fearing throughout the two days we’ve been working on the car.

We were lucky until about 4 p.m. Saturday.  We’d made a few runs to the local autoparts stores to get minor supplies and tools, which is par for the course.  But then disaster struck.  Pierre had disassembled a difficult part, an oil drain tube that runs down from the turbocharger to the oil pan.  This tube was leaking oil, so I had ordered a special grommet and two rubber O-rings specifically for it.  They were shipped from a Mercedes dealer in California, and each plastic package was labeled exactly as we expected: Seal, turbocharger oil return, 1984 Mercedes 300D.  These silly little rubber circles cost $0.94 each, which is probably ten times what they cost to make, but when you need them you’ll pay whatever it takes (and they know it).

Except when they’re wrong.  After cutting off the old O-rings, we discovered that they’d shipped us the wrong ones.  And as quick as that, we were dead in the water.  Without the proper rings we couldn’t reassemble.  The system would leak oil like an old airplane radial engine.  That meant our other jobs scheduled for Sunday couldn’t be completed either, since they required a running engine.  We were completely screwed.

This is where you find out what your mechanic is made of.  Pierre didn’t disappoint.  First, he committed that if we couldn’t get this engine back together, he would personally harass certain senior management of the company who sold us the part until they paid for the local Mercedes dealer to fix it next week.  Then, he told me that were going O-ring shopping.  And so we spent the next hour or so digging through O-rings at various hardware and autoparts stores in an attempt to find one that was close enough to do the job.

That’s how we ended up working in the dark at 5:45, with the air temperature once again plummeting, when we should have been done for the day and taking hot showers.  We found some O-rings that might work, bought a bunch of them in case we had to double them up, and Pierre meticulously tested them on the drain tube until he was satisfied they would work.  I think he had to do that before he could relax and eat dinner with us in the house, just to know that the job was going to be OK.

Other than that it was a great day.  We did a complete four-wheel brake & bearing job including the parking brakes, adjusted the valves, replaced both engine mounts, an oil change, and replaced the rear shock absorbers.  The list on the wall is getting considerably shorter. Today won’t be completely easy, as we’ve still got some messy and time-consuming tasks on the list, but if it goes well we will have time to put the wheels back on and the seats back in, and take her out for a test drive.  It’s 6:45 a.m. now, and time for me to get ready to meet Pierre in the carport.

This week we’re making a big push toward getting the Mercedes 300D sorted out, and I’m really pumped about it.

For nearly a month I’ve been anticipating the arrival of Pierre Hedary, the young Mercedes guru from Florida who I’ve known for a few years.  Rather than taking the slow road to sorting out the mechanical issues of the old car, Pierre and I have been planning this intense three-day repair session so that the car will be ready to go—anywhere— by Monday.  It’s the crash-diet version of Mercedes repair.

I wouldn’t even attempt this if the car weren’t basically sound.  Although the task list is long, I was driving the car daily before I removed the interior, so I have had a chance to verify that it has “good bones,” meaning that it isn’t just a bottomless money pit.  It just needs a bunch of maintenance.  So for the past three weeks I’ve been identifying what the car needs (sharing photos with Pierre), and buying lots of parts.

I also wouldn’t attempt this if I didn’t have a lot of faith in Pierre.  Flying a mechanic across the country is a big investment.  He has to be extraordinarily competent in his specialty, unflappable, realistic, and fast, to make the investment worthwhile.  Today, after about ten hours of work, it’s clear that he is all of those things.  He’s sort of the Mercedes version of Super Terry, but taller.

We set him up in the Airstream guest house last night, right next to the car.  This morning we both “clocked in” at 7:38 a.m. and began work.  I already had the car set up on jack stands, with all four wheels removed, and most of the interior is still sitting on the back patio, so access to everything is easy.  I also arranged all the parts by car system, brought all my tools, and set up various things we’d need: shop light, tarps, trash barrel, garden hose, wash basin, etc.  The carport is now a functioning shop.

Here’s what Pierre did today (I played go-fer, assistant, and parts cleaner most of the time):

• air conditioning overhaul with new compressor, drier, expansion valve, hose insulation, and R-134a
• fixed a climate control actuator inside the dash
• cooling system overhaul with radiator, water pump, thermostat, one hose, and fluid
• replaced all four belts

Everything went well, and at the end I had air conditioning that was blowing out at 46 degrees on a 74 degree day, while the engine was idling.  (It should do a little better at speed.)  We did a few more tweaks to squeeze out a little more cooling performance and then wrapped up. It was a full ten hour day, with 90 minutes for lunch and parts shopping. This was an experience that Pierre described as “fun.”  He’s a guy who really likes his work.

Of course, it didn’t all go to plan.  We discovered a few parts that I thought were leaking or faulty really weren’t.  That was good news.  We also found a couple of things that I didn’t catch, like a bad relay, and questionable upper control arms in the suspension.  Fortunately, Pierre is the sort of guy who has suspension parts in his luggage, just in case.  Overall, we’re doing pretty well.

Tomorrow we start by installing new engine mounts, then go on to valve adjustment, then start the four-wheel brake overhaul.  I’m particularly looking forward to those jobs because I want to learn how to do them myself.  I don’t need to; it just seems like an opportunity to learn something new.  The hands-on time with the Mercedes  brakes may serve me well someday when I need to do a disc brake repair on the Airstream.

It’s great to see the car coming back to its original performance.  It’s also fun to have friends dropping in to watch.  Today we were visited by my friend Rob, neighbor Mike, and Eleanor at various points.  Brett called in to see how it was going as well.  I’m expecting another guy to drop in tomorrow.  And most people want to help. It’s a version of Tom Sawyer whitewashing the fence.

If everything goes well, we will wrap up Sunday afternoon, bolt in a couple of seats, and take the car for a celebratory drive up the Catalina Highway.  Stay tuned.