My Custom 1980 W116 300SD Project Part 2 - Page 7 - PeachParts Mercedes-Benz Forum

vwnate1 · #91 06-22-2018, 04:37 PM

The reasons I like this thread so much are :

You have impressive skills IMO and are not afraid to show them and to explain not only the hows of what you're doing but, the often more important WHY .

I'm no slouch as a Journeyman Mechanic but I'm not that good on the final fit and finish as you are .

I assume the cowl rust was caused by accumulated leaves and debris ? .

Just to - day I was looking at a nice old California W116 with going flat tires and spider webs between it and the ground, thinking 'what a waste' as I know there are some serious W116 loves out there ~ I'm no fan of the S Klasses unless I'm riding shotgun in one .

Squiggle Dog · #92 06-22-2018, 06:02 PM

Quote:

Originally Posted by vwnate1

The reasons I like this thread so much are :

You have impressive skills IMO and are not afraid to show them and to explain not only the hows of what you're doing but, the often more important WHY .

I'm no slouch as a Journeyman Mechanic but I'm not that good on the final fit and finish as you are .

I assume the cowl rust was caused by accumulated leaves and debris ? .

Just to - day I was looking at a nice old California W116 with going flat tires and spider webs between it and the ground, thinking 'what a waste' as I know there are some serious W116 loves out there ~ I'm no fan of the S Klasses unless I'm riding shotgun in one .

Thanks for the kind words. I've not had any training and I found that due to a combination of preferring vintage vehicles and not having much money, that I've been forced into learning how to do my own repairs, but ultimately I'm able to have some control over the quality of the vehicle I own.

Unfortunately, the W116 300SD isn't as popular as the W123 and W126, etc., so I've found myself being the first one documented to do some of the jobs. Fortunately, I've made large strides over the years just by figuring things out on my own, and hopefully they will help the next person.

I guess that's part of the reason I like to document things so much--because it's been highly lacking in this particular model of car and it's been frustrating. I also feel a lot better now about having started off with a car that was so rough.

The cowl was packed full of pine needles and other debris which had become a wet soil that seemed to never dry. I removed handfuls of it!

ROLLGUY · #93 06-22-2018, 06:36 PM

Although there are not many things mechanical that scare me, I don't think I would have attempted delving into the HVAC system like you have. I applaud you and your efforts. I too like these cars, and keeping them serviced and repaired is actually kinda fun. I have had at least one Mercedes-Benz Diesel in my possession for about 20 years (as many as 17 at one time!), and I don't see myself NOT working on and driving one till the day they take my drivers license away

.

vwnate1 · #94 06-22-2018, 06:57 PM

I figured that was the cause of the rust ~ I grew up Down East and it was 50/50 between the salt and the pine needles forcing vehicles to rust away .

So many forget : RUST NEVER SLEEPS

.

My 1969 Chevy C/10 pickup truck spent most of it's life on a ranch in dry TEXAS, parked under a tree so it wouldn't get too hot whenever the foreman needed it .

Nice shiny original paint and rubber floor mat .

Totally rusted out inner cowl, lower A pillars and rocker panels .

I was on a road rally in North Cal. in it when I went a shade too fast and ripped the cab's rusty floor right off the cab proper ~ that was a scary ride home .

Like you, I learned due to need ~ in the 1960's there weren't easy places to get parts for the pre war stuff we had so learn and adapt were the by words .

Squiggle Dog · #95 06-22-2018, 07:17 PM

Quote:

Originally Posted by ROLLGUY

Although there are not many things mechanical that scare me, I don't think I would have attempted delving into the HVAC system like you have. I applaud you and your efforts. I too like these cars, and keeping them serviced and repaired is actually kinda fun. I have had at least one Mercedes-Benz Diesel in my possession for about 20 years (as many as 17 at one time!), and I don't see myself NOT working on and driving one till the day they take my drivers license away

.

The HVAC system is pretty scary, but I'm trying to take it one component at a time, though I tend to jump around a lot, and I get overwhelmed trying to get the whole picture of how it needs to work together.

In my younger years, I just thought a diesel engine was a gasoline engine that was setup to run on poor fuel. I was used to 1950s American cars as I liked the simplicity and styling of them. But, as a young adult in 2004, I needed a cheap car that didn't need a frame-off restoration and had a choice between a 1977 Plymouth Volare for $500 or a 1980 Mercedes 300SD for $400.

The 1977 Plymouth was in good condition for the age and was maintained well. It was fast and had good brakes. The 1980 Mercedes had a rebuilt transmission and the interior was like new, but it had rust bubbles under the paint. It seemed like a really good deal, but it had 380,000 miles on the original engine and seemed like it would cost a fortunate if anything broke.

I told the owner of the Plymouth my situation, and he got snippy at me and told me to just go buy the Mercedes. When I went to pick up the Mercedes, the battery was dead, so the seller sold the car to me for $300. I spent $100 on a new Bosch battery, which wiped me out financially.

I drove the car for a while with a leaking primer pump because I didn't have the money to fix it. I drove it for a while without a thermostat, too. The power windows didn't work, and neither did the heater or the air conditioning. I finally took it to a shop "to get the air conditioning charged" because I was suffocating in a car in which the windows wouldn't go down. It actually blew cold for about a day, and that was it.

I removed the driver side door panel, breaking the plastic tabs because I didn't understand how it came off. I removed the window regulator and saw that it was bent. I drove the car with the door panel off and had a piece of wood that I wedged under the glass when I wanted the window to stay up. One time when I lowered the window, it slipped out of my hand and shattered. I couldn't afford a new glass, so I cut one out of a piece of Lexan.

I loved the way the car drove and handled. 60 MPH felt like 30. It had more climbing power up steep hills than even the American V8s I was used to. The fuel economy was incredible. I loved the sound and look of the engine. As far as I was concerned, it was the best engine ever made. But, I had no idea how to fix the car, so I sold it on eBay for $600.

Four years later, during which time I was driving a beat-up International Travellall, I saw an ad on craigslist for a 1979 300SD for free. It had already been parted out and was missing the front wire harness, bumper, grille, alternator, exhaust system, etc., and the interior was full of water. It cracked me up because the seller said that it could be driven home. Yeah, right. I ended up finding the wrecking yards had some W116s in there, so I made the 300SD into a complete car, which made a fantastic daily driver.

Ever since learning how to fix these properly, I've been hooked, though the power windows, power sunroof, and climate control have been driving me crazy, so I've been gradually ripping them out and converting them to manual for simplicity and reliability.

I don't have much interest in driving anything other than Mercedes diesels. Gas engines don't interest me much anymore as they seem too complicated and don't have the longevity or fuel economy. I like the styling of 1930s-1950s American cars, but they are a bit unrefined and lack the safety and engineering that went into the Mercedes automobiles. I like Citroëns and Rolls-Royces, but they aren't really practical as sole daily drivers due to the cost and availability of parts.

Squiggle Dog · #96 06-29-2018, 05:56 PM

Look at how rusted the cowl partition in my car was compared to the one I removed from the parts car.

Once I had the partition out, I saw that the inside of the cowl had also rusted through. It got even worse where you can't see. The bottom surface was heavily pitted and I poked a screwdriver through in several places. So much for simply plug-welding a new partition in place.

I have an 85 amp wire feed welder, so I cut twenty holes in a sheet of metal that I cut from the parts car, and after cleaning the surfaces to bare metal, I tried plug welding the holes at several different settings. Nope. The stick welder isn't going to cut it. I would destroy the metal for sure. A proper MIG welder would cost several hundred dollars or more, even used. I could get a cheap $200 one from Harbor Freight, but then I'd still need to get a gas bottle, which could be another $100 or so on top of that (just guessing). Then with now having to weld in patch panels, I think it's going to be wiser and cheaper to pay to have a professional do the work. It's money I shouldn't be spending, but I'm not going to just J-B Weld it together and call it good.

I cut out the rusted-through and pitted sections of metal. It was a larger section than I had hoped, and there are still about two pinholes and three pits that will need to be filled in.

It looks like it's probably going to cost a couple hundred dollars to have the panels welded in. The area that has to be welded floats about an inch over the right side wire harness that exits the firewall, so I'm hoping it can be shielded enough to stay in place.

Squiggle Dog · #97 06-29-2018, 05:58 PM

I got the patch panels cut out of the parts car. Ironically, even though the rest of the car was super rusty, this part wasn't. It's a testament to keeping the cowl drains clear. I cut the panels larger than needed and placed them under the area on my car so I could draw marker lines for a guide as where to cut.

I used a Dremel rotary tool with a flex shaft attachment and cutoff discs for all the metal cutting. I cut slightly larger than the lines so I could slowly trim them down until they fit on the cowl.

It was several hours of tedious work, but I got them to fit pretty well.

The cowl opening needs to be 232mm from the widest point to the widest point. It's not very scientific, but it seemed to be accurate.

I had to do the patch panels in two sections to make it possible to access the back to remove and weld them.

Squiggle Dog · #98 07-06-2018, 11:43 PM

I looked around for someone who could weld the patch panels onto the cowl, but only one person actually responded and he was an hour away. I rigged my car so I could drive it to him. He was a war veteran and had a really good attitude, unlike many people these days that want to do nothing but complain about why something can't be done--his attitude was, "I know it can be done, I don't mind a challenge, let's see how we can make this work."

He did a good job and was pleasant to deal with, though he didn't have a way to hold the panels in place while welding them. I had magnets which would have worked, but he said the magnets would mess with the welder. Even if they were just on long enough for the panels to be tacked, it would have helped. He held the panels in place with his hands, and though he got pretty close, there are some spots were they weren't lined up perfectly. I'm a perfectionist and things like that bother me, but that's the thing--when other people work on your car, you're at their mercy.

It took a little over two hours and he only charged the minimum shop charge of $150, so that was nice. I feel he was honest and didn't take advantage of me. When I was driving back home, a W115 diesel passed me on the left and gave me the thumbs up. It had nice dark blue paint, custom wheels, no bumpers, and a license plate that read "BLU PIG". Then when I was near home, a guy in a Volkswagen New Beetle Turbo Diesel gave me a thumbs up.

The next day, I ground down the welds to get them as flat as possible.

There were some low spots and pinholes in the welds that I filled with J-B Weld.

Here's the partition welded in place. I bought some weld-through high zinc primer that I intended to apply between the overlapped metal areas before the partition was welded in. I sprayed some on the bottom of the partition with it, but it came out as a weird powder, and then the nozzle clogged. Hopefully it helped.

vwnate1 · #99 07-06-2018, 11:58 PM

Good work here ! .

Squiggle Dog · #**100** 07-12-2018, 03:00 PM

I have to say that I am very frustrated with the business practices of some companies these days. Well over a month ago (June 4th), I placed an order with MBOEMParts.com and I still have not received it all. A box with some of the parts arrived, and then on the June 16th, I got an email informing me that the rest of the parts were on the way, and was given a tracking number. I followed the tracking number from Illinois to the sorting facility here in Arizona. On the day it was supposed to arrive, the FedEx truck never stopped by. So, I checked the tracking number and it said that the package was damaged in transit and was being returned to the shipper. In the meantime, I've been emailing MBOEMParts.com, asking them for updates. They are completely ignoring me. I finally had to initiate a dispute on my credit card, and am still awaiting to hear back.

ACParts.com has been completely ignoring me for over a month, despite my constantly messaging them asking for them to please take care of the wrong parts they sent, and to refund me for the order they never sent, plus the shipping. I couldn't wait anymore, so I just bought some premade hoses from Klima Design Works and filled out Return Goods Authorization Forms so I could send my entire order back to ACParts.com. They never responded to those. So, I had to initiate a dispute on my credit card for both of the transactions with them. This is ridiculous! Keep in mind that I placed the orders on May 9th.

The seam sealer in the cowl still hasn't fully cured even after a week with it being 114F, so in the meantime I've been working on the blower motor case. I'm using one from a manual system, but it turns out those don't have a 100% recirculating air feature. The flap moves upward and creates at best an 80% cabin air, 20% outside air mixture. I want the 100% recirculating cabin air feature for maximum air conditioning performance so the 120F desert heat isn't warming up the cabin air.

So, in order to have 100% recirculating air, I took apart the blower motor case from my car so I could transplant the flap and sealing surface onto the one I will be using. The case comes apart with clips, but of course there's also a rivet holding it together, making removal more difficult. I drilled it out.

Once the case was apart, I was able to drill out the rivet holding the piece of the case I needed to remove that's accessible from inside, and then drilled out the rivets on the outside.

The flap sealing piece is removed and can be transplanted onto the manual case.

To remove the flap, I pried back the tabs so it could be lifted away from the bar, and then the bar was slid out.

The flap on top is the one removed from the automatic climate control blower motor case. It's flat and designed to have foam on each side. The one on the bottom is the one from the manual case I will be using, and it has a lip and wasn't set up for recirculating air. All it really did was seal off the cabin air during defrosting and then raise up to allow a mixture of cabin and outside air the rest of the time.

Squiggle Dog · #**101** 07-12-2018, 03:02 PM

There is another flap inside the manual blower motor case which adjusts the flow of air dependent on the speed of the blower motor for microtuning of air flow. I put new 1/8" thick extra soft high temperature resilient silicone foam on it. The plastic retainers weren't staying in place, so I had to use a heat gun and wedge the prongs apart with a thick flat blade screwdriver so there would be enough tension to hold them in place. This probably wouldn't have been necessary if I didn't use such firm foam.

I cleaned up the recirculating air flap from the automatic case, put new 1/8" thick high temperature resilient silicone foam with adhesive back on both sides, and installed it in the case. I tried to install the plastic retainers on both sides, but unlike the other flap I did, the plastic retainers would not stay in place. So, I had to remove them and fill the little holes in the foam with some twelve-year-old POR-Patch clear seam sealer that I had. I would liked to have used new foam, but I didn't have any left, didn't want to spend over $40 for another 12"X12" square of it, and then deal with having to cut it out and fit it into place. The automatic cases with 100% recirculating air had a foam strip that seals against the flap, so I installed one in the manual case.

I put new 3/16" diameter neoprene foam cord from McMaster-Carr (the same stuff I used in the climate control case) in between the blower motor case halves.

Installing the rivet that helps hold the case halves together. Once again, McMaster-Carr came through. I needed 5/32" rivets for 3/16"-1/4" material thickness. Of course, none of the hardware stores carried them, and any hope I'd have of getting them would be to drive downtown in this heat. McMaster-Carr had some all-aluminum sealing ones (97524A114) that were identical to the ones Mercedes used. I ordered them online Wednesday afternoon, and they were delivered to my door the next day.

I installed the recirculating air flap sealing piece with sealant and rivets. Figuring out where to drill the holes was tricky, and I had to fill the holes with hot plastic and re-drill until I got it perfect. Now this blower case will have a recirculating air function, and with much less parts than the one my car originally had. One vacuum pod and one cable are all that control the flaps.

vwnate1 · #**102** 07-12-2018, 04:14 PM

I'm not 100 % sure I'd want 100% recirculated air.....

You're Oh, so right about vendors these days ~ Pelican Parts doesn't have anyonw who understands anything about parts in their ordering section so now every time I place an order they want to go back and forth about 'do you really want this part ?' and 'are you sure you want to willcall it ?' plus the ever popular "I have to have the VIN before ordering this part' when it's a W123 part that has NO OTHER CHOICES .

Jesus H. Keerist, get with the program please .

Squiggle Dog · #**103** 07-12-2018, 04:22 PM

Quote:

Originally Posted by vwnate1

I'm not 100 % sure I'd want 100% recirculated air.....

You're Oh, so right about vendors these days ~ Pelican Parts doesn't have anyonw who understands anything about parts in their ordering section so now every time I place an order they want to go back and forth about 'do you really want this part ?' and 'are you sure you want to willcall it ?' plus the ever popular "I have to have the VIN before ordering this part' when it's a W123 part that has NO OTHER CHOICES .

Jesus H. Keerist, get with the program please .

The 100% recirculated air is supposed to only happen when the air conditioning is on the highest setting. The rest of the time it would be set taking in outside air. The blower motor case that's original to my car did 100% recirculated air on the maximum setting. The manual blower motor case I'm going to use did not, so I just altered it so that it would and I wouldn't be losing the 100% recirculating air feature at maximum cooling.

vwnate1 · #**104** 07-12-2018, 04:24 PM

I understand completely, I have also been following the W123 recirculating AC modification threads too .

I have some experience with stale air in older vehicles, I don't like it .

Colorado220 · #**105** 07-16-2018, 05:02 PM

Way awesome bud! I bet your car loves you! Will be following this!