where_the_heffalump_roams 917 AF

Pacific Northwest yetti

Expedition Medic
That sounds like a really great program! It’s much needed in many parts of central and south America, hell in many parts of the world.

One thing at a time, I am decent with electrical and don’t have a clue why your switch is doing that. I’d have to take a volt meter and start tracing to find a voltage drop. Im assuming there is a failed relay in line that’s dumping the voltage, or shorted out. I could also be completely off base. It’s just time consuming but not necessarily hard. A decent volt meter, is worth its weight in gold. Just keep plugging away.

No worries on the Kp referral, even though he is my brother. The recommendation came from the knowledge and skill that shop has. Knowing they would treat you right and probably be able to figure it out, and not BS you. He is a straight shooter, to a fault. It’s one of the best in the country. And its pretty much word of mouth, he does not advertise unless it’s for the OEV product line.

Depending on your battery capacity, maybe a 12volt DC is the way to go. Versus replacing the generator. A good DC/DC charger should out 30amps back into the bank. Cruise N Comfort makes a good Unit. Dometic makes a 12volt roof top unit now as well that works pretty well. And I believe a few others on the market.


Generators are probably cheaper than a big battery bank, followed by solar and/or DC/DC charge system.
 
The current thought process is to keep a generator circuit to feed the batteries when not driving and during low solar harvesting. But if the a/c is ran off the batteries, I could potentially have a more usable a/c system. I believe that a/c system has a maximum draw at 55 amp/hr. I think the alternator can handle that and still power the supporting systems when driving but I don't know for sure. It feeds 60-70 amp/hr to the batteries while at idle, it may do more when driving. Another reason why I like that idea, is that I can potentially use the truck's engine to charge the battery as a back up if the generator was out of fuel or not working, charge the batteries via shore power (still trying to figure out how). Whereas the a/c is currently reliant on the non-functioning generator circuit.

In other (sad) news. I finally received the brake parts from Fedex last night, what a hassle that was...
I went to Bett's in San Leandro and spent the morning there. They found the brake actuators were working and not seized now. The brake shoes expand when the service brakes and parking brake are applied. I also noticed there was signifiant pad life difference between the top and and bottom shoes at the right rear corner. They did not replace any parts as they felt they were functioning at that time but couldn't explain why there wasn't enough pressure on the shoes/drums to keep the truck from rolling. After 3 hours of shop time, they opted to not continue. They were wondering if there was might be faulty valve that wasn't allowing enough pressure to apply to the parking brake.

I'm wondering if it is still that wedge actuator. If one piston was previously seized but know moving. Could it be not applying enough pressure to lock the brakes? I'm now scrambling to find a shop that can help with this again. I'm working this weekend but off for a few days after. I may try to find usable jack stands and swap out the actuator myself. I'm open to any thoughts or referrals to a shop that can help.
 
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Joe917

Explorer
The "parking brake" is the spring brake. It engages when there is no pressure to the spring brake side of the canister. It is a massive spring that is held back by air pressure. when you stop and engage the spring brake you hear the sudden air escape from the spring brake chamber, this pushes the wedge in. It is also your emergency brake in case of a system pressure loss. Those big double skid marks you see on the highway sometimes are a trailer having a sudden air loss which engages the spring brakes.

As far as shore power charging, it has the connection and charger for 230 volt, so in Ecuador or Europe, etc you just plug in. We never needed more power than supplied by the solar or b to b charger. Also we never had any generator issues. The simplest option is to add a 115V battery charger and connect the dc to the system under the dinette.
 

Joe917

Explorer
BTW the alternator is 200 Amp 24 V. Don't forget to grease it when you do your routine service, also there is a grease cup on top of the transmission that needs regular attention.
 
@Neil: Correct, my understanding of how the parking brakes work is that the "default" is for the spring in the air canister to extend the rod and activate the wedge system. When air enters the chamber of the canister, it releases the parking brakes. The shop was wondering if there might be remaining pressured air in the system. I did decompress the air tanks yesterday, but this did not get the parking brakes to lock.

@Joe: Thanks for the service tips Joe! I've not serviced the alternator or the transmission. I'll add that to the routines.
 
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This lifestyle if full of challenges and adventures. Got off of work at 03:30 AM today and had coffee with a work friend later this morning. The plan today is to head up to a friends house to and focus the week on heffalump repairs. As I'm on the freeway, I need to downshift and find my shifter is stuck, I manage to get to an offramp, somehow get into neutral, and safely park off the side. I find that the shift linkage is jammed against the turbo. the engine looks tilted and I find a broken motor mount. I spend 1-2 hours calling around and find a mobile mechanic/welder who thinks they can help but they are a few hours out. So I try to figure out how I can get the engine lifted to see of the mount can be removed. I remove the alternator and found that it had snapped when the engine mount gave. :)
I'm hoping we get the engine mount fabricated and the alternator welded up. I'm not sure if they can do that without damanging the internals....
I've emailed Hans in Canada already to see if he can source replacement parts.

Recent Heffalump challenges have been, well challenging. But it's all in part of the this life and I'm rolling with it all. :)
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I'm guessing it lost its tensile strength over the years. I was cruising at 80 km/hr on the highway when it gave.
A mobile welder/mechanic came out and, jacked up the engine, and got it pretty aligned. He threw a bead of weld across the fracture and a hardened steel plate across the top.

The alternator can't be welded unfortunately. So it was JB "welded" and it is curing now. The hope is that once it cures tonight, I can reinstall it, and try to drive 200 miles a friends house until and park it. There it will set until a new alternator is and a mount is sourced. I'm considering replacing the rest of the mounts as as preventative measure. I've emailed a few places about an alternator. I did ask Hans with unimogcananada about a spare alternator last year and was quoted $2.5K to get one from the dealer! That's an option, but I am also looking at other avenues.
 
I know a 917 isn’t a Unimog, but still, I’ve found Neil Webster at Merex parts to be beyond exceedingly helpful at sourcing parts. Including some non Unimog parts for the OM314 in my 88 Brazilian Bandeirante OJ50. Admittedly, engine parts that maybe cross referenced with early Unimog diesels.
But especially with regards to non Mog parts, PLEASE have the part number(s) first. One can find online unofficial EPC-like sites that are much easier to use than the official EPC, and free.
With regards to alternators, and this may not apply to yours, my U500NA came with a “large J180” mount. I of course ordered the M37 option (12v because NA market unfortunately, but 270a) because of intended camper box.
The divorced (usual LN4800 series a bit too long re motor mount) rectifier usually, but once the alternator itself (Leece Neville 4856AA) failed every 20k miles x at least 3. The rectifiers became ultra expensive and then unavailable.
Someone who follows this forum with an identical optioned U500NA (I shared my option list with 1st owner before he ordered it) somehow squeezed a 275a integral rectifier Delco 40si in place, but it wouldn’t fit on mine. But the 28si does fit easily. 200a from Delco, I have a 240a from
There’s also a 24v/110a version.
They’re cheap enough to carry a genuine Delco 200a spare on long outside NA trips. Not that I’ve needed it.
The point of this is that there MAY be an inexpensive easily sourced alternative to a $2500 alternator.
And even if we all like the idea of a 24v/200a alternator with a camper box, but 110a is probably enough.
 
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PS I visited Guatemala and Lago Atitlan summer of 69 (the summer of the Charlie Manson murders), on the way back from a shoestring trip to South America.
 

DiploStrat

Expedition Leader
Some random comments:

-- After dealing with a 12v air conditioner that was loud and did not cool well, I went with a 110v Houghton 13.5k BTU unit. Much, much quieter. Designed to have a soft start capability, I still had to add a soft start to use with a 2Kw inverter. Probably fine with a 3kw unit. The big advantage is it projects below the roof and blows the air sideways so it actually cools the camper. We used the heat pump this morning as our Dual Top is in the shop. If you go 12v or 24v, remember that when recharging your batteries your charger is likely to get very, as in 150F+ HOT. We had to relocate ours outside of the camper into one of the lower storage boxes.

-- Our truck is set up with a Magnum inverter/charger. I added a 50A Victron 110/220v charger. So far, that has worked perfectly. In fact, I left the US cord in the US.

N.B. To connect my Victron, which has a US plug, I carry a 100 foot US extension cord. I removed the US and installed small quick disconnect from Tough Leads. To this I can attach a European "Commando" plug, a UK plug or Schuko plug. https://toughleads.co.uk/collection...extension-leads/products/letter-box-connector Great people to work with.


Adrian
Director
Tough Leads Ltd
New House Farm, Crimchard, Chard. TA20 1JS
www.toughleads.co.uk
 
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Hello Charles and thanks for the tips!
I did purchase/download an EPC program to my mac but haven’t gotten it to work.
Can you please share links to where similar programs can be used?

Also, I googled your contact and it looks like he is in Mexico. If that is correct, do you know if he ships internationally?

If anyone has a EPC, I would greatly appreciate a part number for
the alternator. The past owner has indicated it is original to the truck.
The VIN is: WDB6761981K030227

I’m crossing my fingers I can secure new casing for this one or more budget friendly option.

Thanks in advance!


Sent from my iPhone using Tapatalk
 
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MogsAndDogs

Active member
Hello Charles and thanks for the tips! I did purchase/download an EPC program to my mac but haven’t gotten it to work. Can you please share links to where similar programs can be used? Also, I googled your contact and it looks like he is in Mexico. If that is correct, do you know if he ships internationally? If anyone has a EPC, I would greatly appreciate a part number for the alternator. The past owner has indicated it is original to the truck. The VIN is: WDB6761981K030227 I’m crossing my fingers I can secure new casing for this one or more budget friendly option. Thanks in advance! Sent from my iPhone using Tapatalk

What horrible luck. Hope you have a long stretch without issue once these things are resolved.

I believe this is the Merex he spoke of. They are in Germany: https://www.merex.de/

These knock-off EPC seem to come and go frequently. I have used this one before: https://webautocats.com/epc/mercedes/4/fg/676198/56s/
 

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