Thinking about a Bus/RV

You know, in the olden days, it wasn't unheard of for some people to get their own Pullman car.

Very difficult to take off road, though.

If you get one, you're going to need bigger wrenches. And jack stands.
 
This weekend I managed to get some time in started working on this round of work on the bus. As these things often go, it wasn't as much work accomplished as I would've liked, but I did make some progress. I was getting over a bad stomach bug and still not feeling 100%, so I was sticking to not doing heavy lifting like removing the wheels - and I'm going to have to do that for some of the work.

I got the fuel filter changed. This bus uses a big cartridge filter rathre than spin-on filters. A lot of truckers prefer the cartridge because it's got a clear housing, and the level of fuel raises as the filter clogs up. Basically it lets you extend your interval and change it when you can see you need to rather than on a schedule. I can see the benefits of that, but I'd have preferred the standard setup. This one wasn't clogged, but it was also the wrong filter that was in there - it was a coarse filtration filter, not the fine filtration spec required by Detroit Diesel. So that's changed.

I also changed a couple of often overlooked items, the desiccant cartridge for the air system (which looked original):

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And also a filter up front for the accessory air system. There's an O-ring on the housing that holds it that wasn't included with the filter, and that didn't come with the new filter - so now I need to get that O-ring and replace that. The O-ring is definitely original, and probably a leak point. I did a quick video on this. I wasn't going to, but it seemed that some folks on the Prevost group hadn't been aware these existed and so I figured it might help someone out:


Another item that's on the list this time around is shocks. 2 of the shocks are easy to change, but the others require removing the wheels. So I changed the 2 easy ones and not the rest. None of them are particularly hard to do, but I'll pull the wheels and do those another day.

I'd ordered a trailer hitch from Prevost and confirmed it looks like it is correct and will fit. However installing it requires removal of the bumper. Not hard, but have to do that. While there, I do also want to change the harmonic damper since it's 23 years old and the silicone in there can harden and stop damping as well. Detroits seem to have less of a problem with that than Cats since they're less torquey engines, but after issues relating to that on my old RV I don't want to deal with them again.

The last thing I was dealing with yesterday was dealing with my power steering leak. This just comes down to the suction hose between the reservoir and the pump hardening and shrinking after 25 years. I just need to buy a new hose. And while at it, I'll flush the original fluid.
 
Ted said:
The Prevost H5-60. 60 feet, articulated, 5 axles, and mod engine. What an Rv that could’ve been!
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I doubt it tows as well as yours.
Albany Tom said:
You know, in the olden days, it wasn't unheard of for some people to get their own Pullman car.

Very difficult to take off road, though.
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False. Very easy to take off-road. Very difficult to get back on the road, though.
 
iamtheari said:
I doubt it tows as well as yours.
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That would be interesting. The way it's set up, the articulating rear is essentially a trailer since it's mid engine and the drive axles are the rear axles for the forward bit. So it would be kinda like a tandem trailer setup.

But that also had an 8V92 (2-stroke) and those are more peaky in horsepower than the Series 60, which wouldn't be ideal... even with 500 HP.
 
iamtheari said:
"Interesting" is the opposite of what I want in any towing scenario.
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You forget who you're talking to.


Note the first part especially in this situation.
 
Ted said:
That would be interesting. The way it's set up, the articulating rear is essentially a trailer ... So it would be kinda like a tandem trailer setup.
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Reversing a double trailer is fun.
 
Spring Ford said:
Reversing a double trailer is fun.
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[thread creep]

When I worked in retail ag supplies, we had to deliver (and retrieve) anhydrous trailers to/from farmers' fields. It was always fun 1.) Hooking up tandem 1000 gal tanks and REALLY fun if 2.) the farmer had left the empty in an akward spot where you had to back up to get out of the field.

Not our tanks - we would be fired if we let our tanks start looking anything like that - but representative of what we dealt with. Double articulating running gear is fun in plowed fields:

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ETA: It was sometimes fun delivering them if you were pulling into a soft field. You need to get far enough into the field that the farmer can get past the tanks to do the headlands. So we would coast into the turn with enough speed to give us enough time to pop the 2500HD into 4-Hi and then put it to the floor and go as far as we could tractor-pull style.

[/thread creep]
 
I've been making progress on the bus in my free time the past couple weeks. All of the rear shocks are on and I've gotten the sway bar end links replaced on one rear corner, which let me get the rear tires on that corner completed. I ended up ordering a bunch more end link bushings (they're the same front and rear, 4 bushings required per corner) as all of the original rubber end link bushings were original and worn/ovaled out. I think that should make a noticeable improvement in handling, not just putting in new bushings but also going to polyurethane from rubber.

I went through and lubed up all the zerk fittings and changed the differential fluid. The diff fluid I ended up putting in 75W-90 instead of the 85W-140 that was in there previously. Prevost originally calls out 85W-140 as the primary, but the manual isn't very well written about this, and it does allow down to a 75W-90. Meritor (who makes the axle) has a service bulletin specifically calling out 75W-90 for any temperature on the hot side, and is good down to -40F instead of the 85W-140 being good down to "only" +10F. Plus, the thinner oil should consume a bit less horsepower and may net a bit more efficiency. Enough to notice or matter? For me, no. But semis run the thinner stuff these days, and it would be nice if I can gain a bit more fuel economy where I can, even though that's not a goal in any sense other than for my own enjoyment.

I got a new power steering suction hose and will need to flush the fluid, and I also have new transmission filters coming and need to change those and flush the fluid there.

Bunch of details, but after these are done a coolant flush is the main other item I need to do. And someone put green coolant in it instead of red, grr. I'll deal with that after our next trip or two though, it's not an urgent concern.
 
I posted another informative/maintenance video showing the locations and functions of all 12 air tanks on my bus.

 
Ted said:
I posted another informative/maintenance video showing the locations and functions of all 12 air tanks on my bus.

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12 air tanks. Did some of the Prevost engineers maybe start out working in Germany? Or Lincoln back in the 70s? I'm sure it all makes sense, it just seems like a lot.
 
Albany Tom said:
12 air tanks. Did some of the Prevost engineers maybe start out working in Germany? Or Lincoln back in the 70s? I'm sure it all makes sense, it just seems like a lot.
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Most of them are because each air spring (there are 8) has its own expansion tank. I'm not sure I fully understand the purpose of that, maybe it helps to keep the spring pressure more constant under suspension oscillations. I know that the suspension is pretty incredible, so whatever they did, it worked, and I'm not questioning their decisions.

Otherwise it's a fairly standard system - "wet tank" off the compressor before the air dryer, and then a tank for each air circuit - forward, rear, and auxiliary.
 
Oh, I like the idea of a tank to catch the water. I don't know anything about air suspension, but I do know that water is a PITA for compressed air systems.
 
The wet tank is supposed to catch some level of air/oil, but the air dryer is the real item that’s supposed to filter all that out. Plus the compressor feeds from the air filter for the engine, so that should keep dust out (mostly).

And yes, water is very bad for air systems on vehicles. Aside from corrosion and causing sticking valves, in the winter if it freezes up parts can simply not work. It causes issues for truckers every winter.
 
Does the wet tank have a spitter valve?

Your bus is a delight to the types of folks who like to learn mechanical/electrical systems.

For me getting to know how all these systems work would be just as much fun as enjoying the bus itself.
 
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Bill said:
Does the wet tank have a spitter valve?
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Yes. All the tanks have drain valves at the bottom. Which you'd know if you watched the video! ;)

Bill said:
Your bus is a delight to the types of folks who like to learn mechanical/electrical systems.

For me getting to know how all these systems work would be just as much fun as enjoying the bus itself.
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Agreed. I've been really enjoying getting to know all of the systems. They're complicated but they're also reliable and maintainable, at least thus far.

The big high-torque impact gun I bought as well as the jack stands have been extremely valuable assets with this bus thus far. I've ended up using them on virtually every job. A lot of them you either need to pull the wheels or at the very least it's beneficial. That's an interesting shift from my old bus where I only pulled the wheels once, and that was just before putting it up for sale when I put the upgraded tires on.

It's also just an elegant design, it shows the difference between the thought the Prevost engineers put into things as a cohesive system vs. the standard stick-and-staple RV like my old one, where it's a shotgun approach with none of the companies talking to (or caring) about each other. Freightliner builds a chassis, and then the meth heads and the box manufacturing company just throw stuff in place that mostly fits around it, with near zero thought or care given to maintainability.

There have been little things here and there, of course, as you'd expect. Leaking fittings, while looking at the turbocharger I found the boost reference hose for the wastegate was worn through and broken. Easy fixes not worthy of a video or real mention. But overall, all this stuff works well. The front of the bus held air for a month solid, which is pretty incredible. However that was at max ride height, where the air pressure is pushing the hardest on the push-to-connect fittings and helps hold more solid. The left rear will hopefully not bleed out overnight as it has been now that I've changed one of the PTC fittings back there that I suspect was leaking, but there are other places that leaks could be occurring. I'll see.

Anyway, yes, it's a lot of fun to learn the systems and far more enjoyable to work on than my old bus was.
 
Today's video on the differential fluid change for those interested:

 
And my video on power steering fluid (forgot to post this one when it first dropped):

 
We just got home from our 11-day, 4k mile (roughly) Spring Break trip heading to the California coast, Yosemite National Park, and bonus stop at Capulin Volcano in New Mexico on the way out.

Leading up to that, I ended up doing/completing a good sum of work. The power steering fluid and filter flush and differential fluid change were some of the items, but I also changed out the sway bar end link bushings with polyurethane (front and rear) and new shocks all around, plus drained the transmission fluid, refilled with fresh, and changed its filters.

And then about 48 hours before leaving, I finally found the source of the slow leak from one of my drive tires: a nail that was into the sidewall. Which moved up the timeline on another modification I wanted to do: converting the bus to super singles.

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Conveniently, I had some super single wheels in stock, but not the tires. And inconveniently, the wheels I had in stock were the 0 offset as opposed to the 2" outset type, which is what I'd prefer (and what I had put onto the Endeavor). Hindsight being 20/20 I would've done that modification differently on it, but oh well. Fortunately, the local truck tire shop did have the super single size I needed in stock, and although it wasn't the type I was originally going for, I think I may have accidentally gotten a better tire than I was planning on buying.

All the modifications worked as expected. The shocks and sway bar bushings helped the ride and handling noticeably. One of the issues I'd noticed before was that the bus would list to one side noticeably when going through a turn, due to the slop in the very dead end link bushings (video coming soon on that one). The steering is better/easier than it was before and the power steering pump and box both sound happier now with fresh fluid. The transmission shifts better - it was a bit sluggish shifting between certain gears and would slip a bit. That's almost entirely gone away but it still persists in a few situations. I probably need to do another drain and refill just of the pan, since there's a lot of fluid in an automatic that doesn't get flushed when doing a drain and fill. But, noticeably improved.

The super singles I find to be a great improvement. They definitely help the ride in back, with no negative impacts on traction that I observed. Really they should have positive impacts in off-road due to the single wider patch vs. the dual narrower patches, and the tires I put on have a more aggressive tread pattern than the "all position" tires on previously. If anything, we think these are quieter, but that may have something to do with tire age as the old ones were a couple years older and I'm sure had a decent number of miles on them.

A bonus of the super single conversion was that we now have a spare tire. Granted it's a single 315, but that will do on the front or the tag as those were the original size. If I had a super single blow out and I needed to limp to a safe location I could switch some tires around to make that work, too. But really since we're normally towing the Jeep behind us, the easiest thing to do would be to pull the tire off, drive it to a place to get refitted, and then come back to put it back on since I carry the tools with me. Still, we like backup plans.

The bus performed very well and I do think that the economy improved slightly from what I'd seen on previous trips, although it wasn't a full apples to apples comparison since we were also towing the Jeep behind. But the engine ran well and seemed happy.

From my observations, there are some things I noted that should be improved.

- Like with the previous bus, the Allison 6-speed has too large of RPM drops in 3-4 and 4-5. 2-3 is more manageable. Part of the issue is that, with the transmission programming, it shifts at about 2000 RPM vs. the 2100 RPM rated power or 2150 RPM redline. If I hold it in a gear and let it get up to 2100-2150 before upshifting that does help get it to a bit higher in the next gear, which helps. But, this engine is allowed to spin to 2500 RPM when under engine braking (meaning the valve springs can handle higher RPM) and the marine versions are rated at 2300 RPM. If I got the redline (meaning fuel cutoff in this case) to go up to 2400, that would put those upshifts in a much better place on uphills, where it creates a problem.

- But also, as I'd observed previously, it looks from fuel flow as though the tune is topping out at 1300 ft-lb of torque rather than something in the 1450-1850 range like I think it should be based on what I've read. Really, I need to either get the DDEC tuning software myself or find someone else who has it to help with checking what tune is in there now and likely making some changes to what I want it to be. It's not uncommon for owners to put lower performance tunes in these if they don't trust the drivers. Still, it has plenty of power. Even coming through the steep mountains on I-80 east of Sacramento, no issues. We weren't maintaining 75 up the grade, but were easily going twice as fast as we were with the old bus last summer. Maybe more.

- The engine is amazingly smoke-free (although maybe this has to do with a weak tune). The only smoke I've seen from the exhaust so far has been at 7,000+ ft elevation, top gear, engine below 1500 RPM coasting, and then flooring it. A bit of smoke until the turbo spooled up then. That, to me, is acceptable.

Now, I need to think some more about what I want to get done before the next trip...
 
And now for this week's video, replacing the sway bar bushings. This was a pretty easy job, but definitely made a noticeable difference!

 
This week's video is on replacing the shocks. This isn't a bad job, although the fronts gave me some surprising difficulty:


When I bought the previous RV, I really didn't end up buying much for new tools, and specifically looking at larger tools for the big fasteners that you find on the suspension. Overall, this didn't really hurt me on that bus. I only ended up removing the wheels and tires from it the one time to put on the super singles and larger steer tires.

When I bought the Prevost I immediately bought tools for the larger fasteners, and I feel like I've been using them almost every job. I was able to do shocks with purely hand tools on the old bus, that would've been a good bit harder on this bus. Everything is bigger and the nuts/bolts have higher torques associated with them. That said, the right tools make the jobs pretty reasonable.
 
In today's video, I change the fluid and filters on the transmission in the bus:

 
We drove the bus to Indianapolis for the eclipse, and stopped by Indiana Dunes National Park on the way. That put about another 1,000 miles on the thing, which made it the first trip we did with the new harmonic damper I added, plus a fresh oil change, first trip with the Flow Below wheel covers, and some more miles on the super singles (videos coming on several of these in the future).

None of these were things that I really expected to make a noticeable difference. That said, the engine does seem to be a bit smoother at idle than previously, and I also feel like the bus doesn't move quite as much under various gusting winds. This could just be perception, but the wheel covers should in theory reduce turbulence along the sides of the bus a little bit, so maybe there's something to it.

For the drive home from Indianapolis I did an audio recording of the full trip from the engine bay. This was actually a request from a YouTube viewer. It was an interesting challenge as I had to buy an audio recorder to add to the collection (which thus far seems to also be improving my audio for upcoming videos), figure out how to mount it in the engine bay, and then do some trial runs to figure out how I needed to set it to get good audio quality rather than massively distorted. It's pretty loud in there.

I'm not sure whether to be happy, sad, or laugh about this, but the upload of that driving audio is actually performing pretty well for my channel:


Now comes the prep for the summer travels. I need to do the valve adjustment on the engine (also setting the mechanical part of the mechanical/electric injector) and replace the air compressor and governor on the engine. From there I've got some other minor things to try to piddle through.
 
NealRomeoGolf said:
To test it more you could've just driven around town today. It was a roller coaster going in and out of MKC today. Bleh.
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One thing I still have to do is a test of how/whether AirTabs impact towing the trailer at all. I’ve been figuring a gusty day is when I should do that. But my desire for efficiency tends to drive me to not driving the bus just for a video since the $5 I’m likely to make off the video gets eaten up every time I start the Series 60.

If it was a C15 it would cost even more, but the sound alone would be worth it.
 
Ted said:
I'm not sure whether to be happy, sad, or laugh about this, but the upload of that driving audio is actually performing pretty well for my channel:
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Now you have done the sleep sounds track, you can do wake-up sounds next time out with the RX7.
 
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This week's video was something I wasn't planning on doing, but I got a viewer request, so I did it. My thoughts on oil changes.

It's almost as controvertial as tires. :)

 
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