Thinking about a Bus/RV

Bill said:
Going to fabricate a block off plate for the tops of the fans?
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Yes, I'm going to put some sheet metal to block that off. I'm also going to treat this like an aircraft and run some RTV around gaps I can find so that the fans are pulling air from the radiator as much as is humanly possible.
 
Pictures of the sandwich plate. I'm going to mount it on the engine and then mark and drill/tap where the holes go.

oil.jpeg oil3.jpeg oil2.jpeg
 
The fan assembly is coming together nicely. I had some leftover baffle material (not as much as I thought) and I was able to get a piece of it to fill in the remaining gap between the sheet metal covering the top parts and the top of the radiator. The bottom I don't think I'll be able to seal quite as well, but ultimately this will be pretty well sealed for air leaks before I put it in.

I also drilled out the holes a bit for the heater hoses going into the bedroom area. Stock they'd just run the hoses through the wall (it's amazing they never rubbed through). I'll be running them with a bit more protection so needed bigger holes. That'll get hooked up.

Since the power steering reservoir was stupidly placed right behind the radiator (blocking a bunch of airflow) from the factory and my new fan setup won't allow that, I welded some angle iron onto the previous bracket after doing some cutting and that will go in the engine bay. End result will be it will be harder to access and will require removing the bedroom closet access panel to get to, but for how often it needs to get filled (in my ownership, that's been never), that's fine and it will still be accessible enough. I may also flush the fluid as part of hooking everything back up. That's about 5 gallons worth, for those counting.

I also bought some Lucas Power Steering fluid with conditioners (that last part is important since they make two variants). Supposedly a lot of big truck guys swear by it for being really thick and helping to take up some of the slop in sloppier steering boxes. While I eventually figure I'll want to upgrade my steering box to the TRW model (it has the Sheperd which is known for having a lot of play), since I have everything apart and need to add some more fluid anyway, I figure I might as well do this.

Still need to helicoil 4 more bolt holes in the timing cover of the engine before I put the oil pan back on. And then I need to weld a nut onto the block heater so I can get a puller on to get it off and put the new one in.

I went through figuring out the wiring I need for the controller, and that's all very straightforward. Only a few wires to solder and a couple of resistors to pull out of the stash to solder in as well. The wiring will still take some time but none of it is too difficult.
 
You could almost do this as a occupation. Taking RV's and flipping them. Ted's RV's has a nice ring to it
 
charheep said:
You could almost do this as a occupation. Taking RV's and flipping them. Ted's RV's has a nice ring to it
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It would be interesting to see what sort of profit margin would exist in something like that.

If I take a look at rough numbers for what we paid for this and adding what we have in it (and will have in it when we're done with the whole thing), I do think we could make a profit off of it. Now if I then wanted to turn that into a $/hr amount, it would be quite low.

I'll also say that in a lot of ways, I don't enjoy the actual labor of working on it so much as I enjoy the results and fruits of the labor. When I'm working on cars and motorcycles, I generally enjoy the work. With the RV there are a lot of jobs that I just don't enjoy quite so much, but I really enjoy the end results driving it down the road. I think the idea of making an occupation out of doing the work to flip doesn't work.

What I have thought about (and this is an area I think I could enjoy more), would be maybe doing some more of the mechanical customizations I've done for others. Those are individual component changes that make a difference and are enjoyable for me and is also an area that I think is tremendously underserved. RVs are so poorly engineered from the factory and there's a lot of room for improvement. With that said I'm also not sure how much market there is, as many RVers seem to not understand the point of what I'm doing.
 
I've been thinking some about what my test plan is going to be for the cooling fans once everything is installed and together. Obviously the real test is going to be when we take it out west on our next trip (and really our real test will be next summer on whatever trips we take). I'm also, at least for a few trips, going to bring the old mechanical fan along in the storage bay with all the parts and tools needed to reinstall it if the electric fans prove that they won't do the job (although I think they will).

There are several goals in order that need to get accomplished:

1) Make sure the fans themselves work. Done. I applied power some time ago to each of them and they pull quite a bit of air.

2) Make sure the fan controllers can control the fans. There's a simple test you can do to watch them ramp up and down. I haven't done this yet, that'll come once they get in the bus. Basically you ground the control wire and that shuts them off. When open circuit they're supposed to go to full blast. So that will be the first test with the fans wired up in the bus.

3) Make sure that the Arduino Uno can control the fan controller. I'll probably start off with a simple time-based step function that will go to off, low, medium, high, and then back down just so I can watch them working.

4) Make sure the Arduino Uno controls the fan controller based off of temperature, and see how that's calibrated. I'll probably make another test program with the target temperatures set below the thermostat temp so I can watch the fans power on and ramp up as coolant temp ramps up.

5) Make sure that the fan controllers don't heat up too much when running all fans at full blast. That's simple, just run them at full blast and see whether the controllers heat up. They have good heat sinks on them and I'm planning on mounting them to the fan housings (standard practice) so they get some cooling air.

6) Make sure the engine side alternator (as opposed to the house side alternator, since I'm running two) can run everything with all the fans running full blast. It should based on its dyno output and my load calculations. If it can't, this will require some electrical changes, mostly routing power from the house side alternator rather than the engine side.

And the last part, really the part at the end question, is how the system performs as far as maintaining temperature goes especially up climbs. I'm hoping there's enough natural airflow that the engine is actually able to cool without the fans running at all for some cases, although we'll see.

My friend is doing more machining on the oil cooler adapter today to add the holes for the inlet and outlet ports, and it really is looking awesome. Can't wait to get the whole thing in.
 
Yesterday I basically spent the whole day working on the bus, and made really good progress. The radiator and fans at this point are all ready to go in, other than doing a little electrical work on them that I don't want to do once the whole setup is in. On Friday I tested the fan controllers and one of them didn't work, the other one worked as expected. The other thing I found was that the controllers have an internal current limiter and they'll shut the fans off if too much current is drawn. I found this out by finding that the controllers can run one fan just fine, and two fans they'll ramp up, and then quit about halfway and ramp down again. So I ordered 4more controllers (3 I needed, 1 spare) and will wire up one per fan. I'll mount them behind the upper fans so that they get active cooling (they have heat sinks and do seem to produce a decent amount of heat) and that will hopefully help them last. It seems most OEMs do that arrangement, so it must be for a reason.

I mounted the power steering reservoir in its new location, bent the transmission dipstick/fill tube a little so it will fit the new (taller) fans, clamped together the hoses for the rear heater unit, and then most annoying of all, got the old block heater out. This was really wedged in place with nature's Loctite (i.e. rust) and I had to weld a nut on and use a puller to get it off. But, it's out, and the new one goes in much easier. It's a significantly different design, and in looking at the issues I had getting this one out, shows that Cat saw the problems and redesigned accordingly. It could've been worse, but it wasn't fun.

Today I'll finish up that wiring on the fan shrouds, get the new block heater in and wired, and then when some friends come over this afternoon we'll get the radiator and fan assembly in. From there it's just bolting it and the intercooler in (I suppose plus the overflow tank), running the wiring for the fan setup, filling all the fluids, and then getting it running and final buttoning up before the test drive. I still need to write up a test script for the Arduino to show that it is controlling the fans via PWM, but I'm less worried about that. I did order a second one figuring that was a single point of a failure that I should have a spare of. Not to mention that I have other uses for one with the Land Rover, etc.

The oil cooler adapter is finished as well, it's a thing of beauty. So now I need to figure out placement of the cooler itself and run the plumbing. I have a few places in mind that I think it would work. None of them are ideal, though, so I need to do some more looking and figuring once the radiator and intercooler are in and I see just how much space I really have.
 
Beautiful work, Ted.
 
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Looking forward to seeing it all work, next time our paths cross.

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I got some more progress made on electrical, and got the Arduino Uno hooked up and reading temperature, and seeming to send a PWM output to the fan controller. I had a few false starts, due to newbie mistakes and not fully knowing what I was looking at.

First one was reading the serial port output, which helps if you set the baud rate on the computer equal to the baud rate that the Arduino has been set to. I think default is 9600, but in this program I started from the guy who programmed it set it to 115200. Once those matched, I got legible information.

Once I got that, I saw that the reading for temperature was -459F (i.e. absolute zero) which is cold enough that I wouldn't need cooling fans, but not very realistic this time of year in Kansas. That came down to two errors. The program I copied was on an Arduino Nano (I'm using the Arduino Uno) and the pins are a little different. The nano has a "REF" pin that lets the computer read the reference voltage going to a 2-wire sensor, and the equivalent of that pin on the Uno is "AREF". However there is also "IOREF" which is a 5V output.

However, as I started digging into the specs a little more, this wasn't necessary. The Arduino can send out a 3.3V or a 5V sensor signal. I'm used to 5V as a standard automotive signal, I suppose he chose 3.3V for lower current. You can also select your supply voltage source, which the computer needs to know in order to determine resistance (since it can't read resistance directly, just voltage). So in the program I copied, the voltage source was "external" (even though it was the internal 3.3V signal) which basically means it needs the REF/AREF pin to tell the computer what that voltage in. Another supported option for voltage reference is "INTERNAL", where it just does the internally supplied 5V source. So I switched to external voltage source, it read a value (albeit too cold, because I still had it plugged into the 3.3V reference). Moved the supply voltage over to the 5V pin and viola, plausible temperature.

I was waiting on some in-line fuses to finish wiring up the individual fans, but then I can run my test program and see how it all works.
 
Ted said:
I got some more progress made on electrical, and got the Arduino Uno hooked up and reading temperature, and seeming to send a PWM output to the fan controller. I had a few false starts, due to newbie mistakes and not fully knowing what I was looking at.

First one was reading the serial port output, which helps if you set the baud rate on the computer equal to the baud rate that the Arduino has been set to. I think default is 9600, but in this program I started from the guy who programmed it set it to 115200. Once those matched, I got legible information.

Once I got that, I saw that the reading for temperature was -459F (i.e. absolute zero) which is cold enough that I wouldn't need cooling fans, but not very realistic this time of year in Kansas. That came down to two errors. The program I copied was on an Arduino Nano (I'm using the Arduino Uno) and the pins are a little different. The nano has a "REF" pin that lets the computer read the reference voltage going to a 2-wire sensor, and the equivalent of that pin on the Uno is "AREF". However there is also "IOREF" which is a 5V output.

However, as I started digging into the specs a little more, this wasn't necessary. The Arduino can send out a 3.3V or a 5V sensor signal. I'm used to 5V as a standard automotive signal, I suppose he chose 3.3V for lower current. You can also select your supply voltage source, which the computer needs to know in order to determine resistance (since it can't read resistance directly, just voltage). So in the program I copied, the voltage source was "external" (even though it was the internal 3.3V signal) which basically means it needs the REF/AREF pin to tell the computer what that voltage in. Another supported option for voltage reference is "INTERNAL", where it just does the internally supplied 5V source. So I switched to external voltage source, it read a value (albeit too cold, because I still had it plugged into the 3.3V reference). Moved the supply voltage over to the 5V pin and viola, plausible temperature.

I was waiting on some in-line fuses to finish wiring up the individual fans, but then I can run my test program and see how it all works.
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Very cool. I suppose that's part of the downside to copying an existing program, but you seem to have the systems knowledge to be able to sort it out quickly. Probably still saves time overall versus having to figure out the entire program from scratch.
 
SoonerAviator said:
Very cool. I suppose that's part of the downside to copying an existing program, but you seem to have the systems knowledge to be able to sort it out quickly. Probably still saves time overall versus having to figure out the entire program from scratch.
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Oh, there's no doubt that it saved me significant time. Although I understand the concepts behind how to read thermistors (or thermocouples), PWM inputs/outputs, etc., I am not a software person and thus trying to make a program from scratch wouldn't have gone well. That said, now that I've made this work (well, assuming the PWM output to the fans works as intended when I test it), I think with looking at a few more programs I'll be able to make the PWM output required for the diesel engine going into the Land Rover.
 
Nothing to add related to the bus, but I've been tinkering with an couple of old (c. 2012) Raspberry Pi's that I had laying around to try to build a Christmas light controller with the boys and can appreciate the mild annoyance of translating code/instructions from one iteration of equipment to another. Since my hardware is nearly 10 years old and all the latest iterations of "How to build a light controller" tutorials seem to be within the past few years, I've had to do a lot of cross-referencing with different versions of pin-outs. Luckily, I have been able to avoid frying the RPi by hooking up a voltage to a GPIO pin, but there have been some close calls. ;)
 
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The fan controller works as intended. :)

More details to finish up...
 
Well yesterday was bipolar. The good news is that everything I've done seems to be working as intended. No leaks. The block heater seals, the oil pan seems sealed. Radiator and intercooler are in. During the test run I found a loose bolt on one of the alternators which I tightened. The wiring is cleaned up and seems to have sufficient strain relief. So, despite my concerns about my projects not working, it seems that everything there is fine. The new oil cooler is in, the lines are run and a hair long but fine overall. No leaks, oil flows through it. The electrical for the oil cooler fan works. We flushed the power steering system and it's back together and topped off. I had to make a bracket for mounting the transmission diptstick now. A lot of little details taken care of.

However during the initial test run, I saw oil dripping on the ground. Upon further inspection, it was coming from the factory oil cooler. It's a steady drip-drip-drip, so not something that I can drive with.

This is annoying for a lot of reasons, not the least of which is that I should've caught this earlier, and I had the coolant drained and basically everything else apart a week ago that is needed to access this area. Plus this is a known weak spot on these engines and something I had a list on to do eventually. But, I didn't do it, so now it's time to do it anyway. I'll feel better once it's done.

Thinking about this I'm pretty certain that this started leaking on the last trip, or maybe the 6Y9 trip (but probably the last trip). After we got back from our last trip that we did, I had noticed that the oil was down. But the oil pan had been leaking ever since I changed the bearings on the engine (that should be fixed now), so I had just assumed that leak had gotten worse. This leak starts as soon as the oil warms up. So I'm sure it was there, draining oil out and clogging up my old radiator and intercooler even further, but it was masked by other items.

So, oh well, next project to do before we can make our next trip.
 
Ted said:
Well yesterday was bipolar. The good news is that everything I've done seems to be working as intended. No leaks. The block heater seals, the oil pan seems sealed. Radiator and intercooler are in. During the test run I found a loose bolt on one of the alternators which I tightened. The wiring is cleaned up and seems to have sufficient strain relief. So, despite my concerns about my projects not working, it seems that everything there is fine. The new oil cooler is in, the lines are run and a hair long but fine overall. No leaks, oil flows through it. The electrical for the oil cooler fan works. We flushed the power steering system and it's back together and topped off. I had to make a bracket for mounting the transmission diptstick now. A lot of little details taken care of.

However during the initial test run, I saw oil dripping on the ground. Upon further inspection, it was coming from the factory oil cooler. It's a steady drip-drip-drip, so not something that I can drive with.

This is annoying for a lot of reasons, not the least of which is that I should've caught this earlier, and I had the coolant drained and basically everything else apart a week ago that is needed to access this area. Plus this is a known weak spot on these engines and something I had a list on to do eventually. But, I didn't do it, so now it's time to do it anyway. I'll feel better once it's done.

Thinking about this I'm pretty certain that this started leaking on the last trip, or maybe the 6Y9 trip (but probably the last trip). After we got back from our last trip that we did, I had noticed that the oil was down. But the oil pan had been leaking ever since I changed the bearings on the engine (that should be fixed now), so I had just assumed that leak had gotten worse. This leak starts as soon as the oil warms up. So I'm sure it was there, draining oil out and clogging up my old radiator and intercooler even further, but it was masked by other items.

So, oh well, next project to do before we can make our next trip.
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The one time you skip on the "while I'm in here" maintenance, it rears its ugly head, lol.
 
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I wouldn't beat yourself up over that one. Who checks an oil cooler for a leak when you already know you have a pan leak? If you did component tests on every part, the job would probably take 2-3x as long.
 
Albany Tom said:
I wouldn't beat yourself up over that one. Who checks an oil cooler for a leak when you already know you have a pan leak? If you did component tests on every part, the job would probably take 2-3x as long.
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You're right, it's definitely not a leak that was inherent or obvious. Leaks can be hard enough to find in general, and having an oil-covered oil pan with a known oil leak definitely didn't give me cause to look further.

One thing I have to say I enjoy about working on this Cat engine is that everything is amazingly serviceable. Sometimes it requires the right combination of socks, extensions, but everything is really not unpleasant to work on. I got the oil filter housing and oil cooler off. The only part that broke in the process was the turbocharger supply line (which goes from the oil filter housing and needs to be disconnected). This was a part that I had been considering replacing since getting the RV as it was pretty rusty. To my shock and amazement, the two bolts that screw into the turbo came out with no problems at all. I had expected them to have been seized up and that I'd have to fight them to get them out without breaking. Nope, came off easily. Granted I did spray some penetrating oil to soak in first, but no desperate measures needed to be taken.

This whole setup is an interesting one. The oil cooler is sandwiched between the block and the oil filter housing. The cooler itself sticks into the main coolant passage in the block, and receives first shot at fresh coolant from the water pump. The two oil ports in the block (output from the pump, and then input back in) have O-rings underneath the oil cooler, but then otherwise share the same gasket (with divisions between the water and oil sections). Then the oil filter housing receives oil and has a network of passages and two bypasses, to allow oil through the cooler (and bypass it if it's plugged), and then go through the filter (and bypass that, too, if it's plugged). This results in a fairly complicated gasket and, since the bolts need to all go through the perimeter of the rectangular opening for the oil cooler in the block, provides no support for some of the center passages. It seems to me that this engine probably never had this section apart, and the gaskets were the old style that was more prone to leaks and also blowing out between the dirty and clean sides of the oil, which was known for taking out HEUI pumps (the high pressure, high dollar oil pumps that fire the injectors). This one didn't seem blown out, but it may have been leaking.

It seems apparent that this oil leak had started sometime over the course of this year. I was able to see where the oil had been leaking in the gaskets and housings, which was a relief (I don't like putting things back together without seeing for sure what was broken), and there was also oil that had been collecting in some of the lower bolt holes, which had then hardened up and I needed to remove. So now, everything is clean and ready to go back together.

This is one where there's 15 bolts with a specific 2-step torque sequence. Definitely requires attention to detail. Not an inherently hard or difficult job, just one that you need to pay close attention to and use your torque wrench.

Of course, this statement assumes that when I put it back together, it doesn't leak. :)
 
I got everything back together, started it and....

leaks. Still. The same as before.

Lots of cursing later I'm looking at what I could've done differently. Overall I think I got it all done well and correctly, However looking up there is an updated part number for the oil filter housing, which shows some structural differences from the pictures in the area of the bolt hole that I'm seeing leaks from. So I'm inclined to replace it, wondering if there isn't a hairline crack in there that I just can't see with my sub-optimal eyes, which would explain the leaks and the fact that it is unchanged from previous. Since the Cat dealer is closed today (and it's not worth doing the 24/7 support for this as I won't get it back together tonight anyway) I'm just going to pull it back apart, look over everything more carefully again, and then go in first thing tomorrow morning to get the parts I need. With any luck, tomorrow afternoon it'll be back together and running, not leaking, and then I can focus on getting the cooling system bled and finally drive it.

The good part is everything else? Doing exactly what it's supposed to do. Of course I haven't driven it yet.
 
You may need to do some NDT on the suspect part. (Hit it with a hammer.) If that doesn’t find the problem, switch to DT. (Hit it with a bigger hammer.)
 
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Man that sucks. Few things are as frustrating in this world as getting an automotive repair project back together (especially if it involves draining fluids) only to have to tear it right back apart because an item was missed or the repair didn't work. Hopefully you're right and there's a hairline crack or other fatigued spot causing the leak and a new part will solve it.
 
SoonerAviator said:
Man that sucks. Few things are as frustrating in this world as getting an automotive repair project back together (especially if it involves draining fluids) only to have to tear it right back apart because an item was missed or the repair didn't work. Hopefully you're right and there's a hairline crack or other fatigued spot causing the leak and a new part will solve it.
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I have to admit this leaves me fairly deflated right now. I don’t think I did anything wrong myself. But we were supposed to leave on our Christmas trip 2 days ago, and this is a day for day slip. Fortunately everything else works and my wife is understanding (kids less so).

I’m back ii the shop taking it all apart, and figuring out what I want to do differently tomorrow.
 
I got everything apart this morning, and I think I figured out what happened. The good news is it's only partly my fault. The other root cause appears to be unintended consequences of continuous improvement.

Background: The oil filter housing gasket is known to be a problem area on these engines. There's actually a service bulletin out, because the original gasket design had a tendency to blow out between the pre-filter and post-filter sides. This would let unfiltered oil get into the engine which could cause major engine problems, but the most common issue was the HEUI pump (high pressure oil pump that fires the injectors) would fail as it is very sensitive. In the interest of continuous improvement, somewhere along the line Caterpillar improved the gasket design. They also improved the oil filter housing design, both have superseded part numbers. I got the new style gasket, and my engine appears to have never been apart previously, and had the old style gasket. I think many of these updates happened with the C7 (which was the next generation of the 3126B, but overall very similar).

Here's a comparison of the two gaskets, new style on the right, old style on the left:

upload_2021-12-19_17-27-28.png

That thick center section of the gasket is what separates the filtered oil from the unfiltered oil, and you can see the difference. But if you look carefully, you will see there are a couple of other areas where the gasket is a bit larger than the old one. One such area is on the top left of the gasket in this picture - not the very top left hole, but the one down from it. You can see on the old style gasket, the main sealing surface follows the same thickness and then opens up for the bolt hole. On the new one, a continuous line is drawn down that angle to meet the bottom of the bolt hole. That is the hole where the engine was leaking.

And when I took a look at the filter housing at that bolt hole, I found a tiny spec of yellow paint:

upload_2021-12-19_17-30-2.png

Where that came from is a good question. I'd sworn I'd checked everything over well, so it may have gotten on that area during install, or it could've been that I just missed it. That was an area not covered by the old gasket, but covered by the new gasket. Looking at the gasket, I can see an indentation where that piece of paint was, and that's just big enough to cause the gasket to not seal and allow that steady drip every 3 seconds.

This makes me feel better. I was afraid there was something just super sensitive about the install procedure that it wouldn't work. That's partly true, but the other part is that the updated design covers areas that the original design didn't, and thus is better, but also means that when being installed on old parts there's a possibility for problems. Also, before I had figured out where the oil leak was, and it was coming from the other side of the housing. So while this was the same part leaking, it was in a different area, and this makes sense as to why.

Cat also updated the oil filter housing, which includes some extra gusseting in this area. Here's my old housing (not actually mine, but this is a picture of the same one:

Engine-Oil-Filter-Bases-Caterpillar-3116--3126-14127273.jpg


And here's the updated style:

CM20210427-1193b-6f189


The gusseting looks like it is primarily there for the bottom parts that jut out, but it's also probably added because of cracking or other issues in that area. On Friday I didn't realize that there was an updated filter housing, or I probably would've just bought one then. This is why I usually shotgun things.

So if the Cat website is right, it looks like my local dealer has both one of these housings, and also a reman oil cooler. I'll probably just buy both along with new gaskets (these are not reusable), and probably also new bolts and hardware for good measure, put it all back together, and hopefully be on our way. At least, that sounds like a good idea...
 
Great troubleshooting @Ted. Get-there-itis is prevalent in all our endeavors; I’m not accusing you of that instead, reminding you the trip happens when it happens. With an understanding spouse, that’s helpful but disappointing kids is always a huge blow to the parent ego.

Keep up the good decision making.
 
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For what it's worth. I had constant oil leaks w/ a small block Chevy, stock stamped metal valve covers with stupid little oblong washers under each bolt to try to spread the force a little more evenly. What finally worked was a high end cork gasket and blue Permatex form-a-gasket. I'm not suggesting that this would work in this application at all, just offering as an example. None of the normal solutions worked, and I believe it's because the covers were warped along the sealing lip.
 
Live from the Cat dealer as I know what they have in stock and the part numbers: “Damn Ted, you looking for a job?” “I think I have one - fixing all my own crap.”
 
I know you are frustrated, now that the leak is fixed, please be safe out there, weather looks favorable for your trip.

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