Shutdown and hi-idle air cylinder repair on Detroit Diesel 8v92TA

This past weekend I installed the Bimba 171S stainless steel air cylinders and Kysor solenoid that I repurposed.  This re-designed the engine shutdown and high-idle limit to use off the shelf commonly available parts.

I took some video of the process.  The first video explains what is going on and why:


The second video shows the installation and then operation of the engine.  It has been edited for brevity as nobody wants to watch 3 hours of mechanic work.


I’m pleased with the outcome as this was a $50 repair overall.  $25 for both cylinders on eBay and $25 for the solenoid on eBay.  Watch to see how I did it.


Scanning manuals to preserve them

I managed to obtain a Ersatzteil-Liste from Europe a month ago.  In English this is a parts-manual.  This one is specific to Cityliner N116 series coaches inclulding the N116/2 and N116/3.  My coach is based on the N116/2.

Because this is a 30 year old manual, I decided to scan it to PDF.  I’m going to keep a copy on my blog as a backup in case something should ever happen to the digital copy at my house and the physical copy in my posession.

It contains difficult to find and irreplaceable information about the parts and diagrams for the coach.

I considered the copyright implications and determined that this is a fair use and educational use.  First Neoplan USA, exited the market in 2002.  Neopart, their subsidiary, is for all intents and purposes dead.  No email, no phone calls… they don’t exist despite a webpage for them.

Auwerter / Neoplan was purchased by MAN Group which is part of the worldwide conglomerate Volkswagen.  They do exist, but they have confirmed, in email that no documenation or information exists for my coach.  Parts availability is extremely limited.

The combination of their legal and real exit from the American market coupled with confirmation that in no market can I get parts or documentation supports a fair use to post the manual online.

This actually helps the market by making it feasible for the remaining owner/operators to continue keeping the vehicles in operation.

I plan to create a page to index the manuals and then a page for each discrete manual.

So far I have collected a couple of manuals, one directly applies, and the other is for the AN440 wiring, which is insightful as to how the systems were designed.

12v Chinese Incense – aka LED 12v bulbs on a 24v system

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I decided to try installing 12v LED bulbs into the 24v lighting system.  The turn and reverse lights worked fine for brief durations…. the rear marker lights smoked after about 5 minutes.  Not good.

Further investigation determined that many corroded connectors existed and the lighting system in it’s present form was an unlimited supply of headaches and frustrations.  While the Hella lights are of high quality, they are 30 years old and are showing the typical abuse that comes with 30 years of being at the back of the bus.

I ordered Maxxima LED units that are sealed, warranted, and unfortunately 12v.  This will call for installing step-down transformers in key locations.  I expect it to work just fine as the LED’s pull a fraction of the energy (10% to be exact) of the incandescent bulbs.

Nipples and Bits from Amazon because they are cheaper….

This evening I got around to figuring out how I was going to deal with the air cylinder replacement.

Let me back up a second and bring readers up to speed.  I bought the bus right before Christmas.  After spending a day getting it ready and arguing with Ritchie Bros that changing a engine belt was not the same as working on it….. I headed East from Los Angeles to Houston.  I did not get very far before Kysor of Michigan Unobtanium cylinder failed active.  This forced the shut-down lever closed near lovely Coachella, CA.

Coachella is lovely if you are a spider, dirt, or a cactus…. beyond that it’s offerings of unlimited wind, sun, and dirt are not terribly appealing.

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I was lucky enough to coast off the freeway and past the bridge when the engine died.  This joy was short lived and I had the privilege of paying $150 for a mobile grease monkey to change my fuel filters and not be able to diagnose anything else….

Fortunately I had CoachNet, so they covered this:

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I promise that Dave and his truck were not cheap.  CoachNet covered it though.  I always consider roadside assistance an investment when it comes to specialty vehicles.  Meanwhile the Genset’s backasswards DC wiring was draining the batteries… which cost me dearly the following day.  More on that another time.

So I finally figured out what it was on Saturday when I could get a good mechanic to come out who knew Detroit Diesels.

This was the offending part:

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The cylinder on the right that is extended….. and 30 years old and no longer made.  So after a bunch of forced learning courtesy of the School of Hard Knocks ® roadside campus….. I ordered a couple of these to move to something standard and easily obtainable.


$25, stainless steel…..

I decided to test fit them today.  I knew that the threaded portion was too long, and I have a plan.  More on that later.

So about this post?  Yea, I needed a brass threaded nipple.  Local Auto Parts Whores (stores) like want $12 for a part I can buy on Amazon for $2.20.

I also ordered a plug for $1.67

And of course no nipple or plug is good without Threadlock….. Loctite 567 to be precise:

Should be here in a couple of days and then I’ll shoot a video of how it goes in and what’s involved….. 🙂

How tall it is not…..

I decided to finally measure the height of the bus today.  I fired it up and let it fully air up the air bags while I drug the big ladder out and got it all set up.  I then hauled a fittingly pink 2×4 up the ladder and laid it across the top of the Air Conditioner.  I used an 8 foot construction level on top of this to verify that the 2×4 was level, because the driveway sure as hell isn’t level.  Heck it’s not even in one place or one piece.  The picture below shows how it shifted up 3/4 of an inch when I parked on it.

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I found the tape measure and convinced my roommate to help me by standing on the end of the tape measure.  It was windy and it wouldn’t stay still.

It turns out the bus is 12.5 feet tall.  Good thing I didn’t bet on that because I sure thought it was taller.

Time for a custom screw or two

Well, my replacement screws from BoltDepot arrived and none of them fit.  It turns out that the screws used on the steering indicator are narrow head M5 screws….. nearly unobtanium.  WTF.

I found a company, Misumi USA that either stocks them or will make them and ship them for $3/ea.  Done.

I also found a set of wiring diagrams for Neoplan USA on eBay.  It’s a $50 gamble that it will shed some light on my bus.

The 24v flasher showed up and it actually works well.  We’ll see if I wind up throwing it away when I convert the turn signals to 12v.

So much fun, so little time.

Time for a new light – adventures in vehicle lighting

I found this gem of a document, (catalog-of-lights-neoplan)a cross reference for old European commercial vehicles that shows which Hella lights were OEM equipment.

So the problem I have is that the OEM lights are worn out.  The plastic is brittle, the lenses are fragile/cracked/glued, and they aren’t working right.

After a bunch of research I settled in on Maxxima Lights.  I’ve ordered a pair of park/turn lights for around $20/ea.

Maxxima LED Light Turn and Park


They are 12v, which means I’m going to open a can of worms with converting my turn signals to 12v.  I’ll probably end up converting all the lighting to 12v.  For now it’s going to start with the turn signals.

For now I’ll just buy the equivalent 12v bulbs and replace them.  That’s a very inexpensive solution to my headache for the short term.  I’ll eventually buy some LED bulbs.

There are some great YouTube videos on understanding bulbs:

Bayonet socket’s explained:

Globe (shape) explained:

I wound up buying some 1155 (12v version of 1251) for $7.39 for 10 on AliExpress shipping from the US with free shipping.  That was the best price I could find anywhere…. shake my head on how they pay for shipping and deliver something that works for that price.

Bought a step-down transformer for $14. That will solve the 12v power issue for all of my lighting probably.

My “large” bulbs are 1683SC which is a BA15S stils S8 globe bulb producing 400 lumens with 28 Watts at 1.02 amps for 28v rated.

The #199 is a darn close match at 12v, 2.25a 28 Watts…. should produce the same lumens.  Now to find an LED equivalent.  Turns out that the 1156 is basically the same bulb.  There is a minor difference in the resistance of the element…. the 1156 is way more common…

Found them on AliExpress for $9.87 for 10 pieces including free shipping from a US Seller.  SMH, not sure how they can do this.. but whatever.



Incompetent Wiring unwound

The weather is nice today…. so I decided to do the unthinkable and start tracing wires under the dash.  Ugh, uber-cluster-fuck.  Several iterations of mis-wiring are present.

My front turn signals did not work when I started.  Oh so many fun things found.

  1. 12 v flasher in a 24v system…. yes Dorothy, voltage mismatch causes bad juju and a fast flash.  Cured via eBay for $8 from a local company.
  2. The bulb was missing from the driver side.  That was easy.
  3. Someone has taken the signal/wiper switch off the steering column before, screws are stripped.  Off to Bolt Depot for replacements…..  Ordered several options, I’m sure something will fit
  4. Still no idea why there is no power getting to the passenger side turn signal.  Opened the dash a bit and discovered a wonderful AP4600 paging car alarm.  Deposited that in the trash.  The first of many items that will be coming out from under the dash as I untangle the wiring.

I’m debating a few things:

  • Convert to 12v turn signal system.  It’s all fed from one place, so this is feasible and would make it easier to get LED lights.
  • Replace front turn signals and markers.  The existing ones are Hella and hella hard to find…. lol.