Help Getting Home! Parked 15 yrs, Big Mountains.. '04 Mack MR688S, AI350

[alabamaslammer]

Hey Everyone, 

I run a small garbage business. I recently purchased a nonrunning 2004 Mack MR688S and am working to put it back into service. 

The first thing I did when getting to the truck was swap out the batteries. The battery disconnect switch was completely corroded so i removed the cable connectors and after cleaning them with my die grinder so they showed clean copper on both sides I vice gripped them together. I connected 4 950 CCA batteries and then tried to crank the truck. Nothing. No crank. Dang it! After an hour or two crawling all over and under the truck I found an 8 gauge red broken wire running to the batteries. I stripped it and twisted it together and voila, the truck cranked up and ran. She ran beautifully. I did not move the truck. I found a motel for $60 and got some burger king. 

The next day I cranked up the truck and drove her across the yard to put air in the tires. After airing up the tires I realized I needed to lower the arms/forks to be under 13'6", so I flipped on the pump. I had already checked the hydraulic fluid level, and despite it missing its cap and sporting a red rag as its cap instead, the fluid looked clean. After lowering the arms fluid started leaking heavily out of both arms on the front load truck. It was white and milky showing water intrusion. I shut off the pump and ratchet strapped the bar connecting the front forks to my front bumper. I then disconnected the front driveshaft to the pump. The leaking stopped, the truck was now safely under max height requirements and the pump was no longer at risk. I then decided to take it for a few laps around the yard and see how she did. The first lap was incredible. The truck drove great on the first lap, upshifting smoothly into 3rd gear on a 200 ft stretch. Halfway through the second lap the truck started to bog on a very slight incline, making jake brake type noises out of the stack before dying. Cranked it and wouldn't start. Cranked it with ether and then it died. When pouring out the old primary filter I noticed green slime in the drain pan. Bought two new fuel filters, drained the tank and poured in 50 gallons of fresh diesel along with some diesel klean. In hindsight I should have poured in biocide or killem. After the filters and fresh fuel the truck fired back up. I parked it thinking I had fixed the problem. I got some burger king and checked into my motel. 

The next day I went about some maintenance. I greased the u-joints and front end, I put gear dope in the rears, added another 40 gallons of fresh fuel, hub oil in the front axle, zip tied loose wires and changed the oil and filters (not realizing there was a third filter, the centri-max). I hooked up the truck to my laptop and fired up allison doc. It had a number of inactive codes but nothing active, and transmission fluid was at the right level. I forgot I had vmac-3 installed and did not scan the eecu or vecu. Then the truck died on a very slight incline. I got a can of starting fluid, and she fired up. I crawled around on the truck looking for something I might have missed - the manual indicated there was a third pre-pump filter but on my truck there did not seem to be one. I took the bosch primer pump off and flushed it out. I bled the injector feed lines from the wrong side. I added 4 bottles of injector cleaner and a quart of ATF. After adding the additives the truck started running much worse. ATF and microbes were likely clogging the filters. 

Any insights appreciated. I am new to Mack trucks but trying to learn everything I can.

Edited October 28 by alabamaslammer

[tjc transport]

it sounds like you have a good solid plan for getting it home.

i wonder if there is still crud/crap in the fuel tank that is plugging up the in tank pickup?

when running, it picks up the crap and plugs the pickup. then when engine off the crud falls off the pickup and restarts the cycle.

i would carry a bunch of fresh filters for the ride home if the pickup and inside of the tank looks clean. 

[mowerman]

Well, that thing looks like it has lots of life left. Good luck with it bud and yes, towing is a fortune. That’s not an option unless you’re working at local and don’t have to go very far…. Bob

[mowerman]

Best of luck let’s get her done:… bob

[mrsmackpaul]

Okay my 2 cents worth

Drain fuel tanks into containers, Im a tight ass

Remove tanks and chuck some old nuts and bolts in them, roll the tanks around on the ground and check how clean they are

Also count the nuts and bolts you chuck in the tank, re count taking them out

 

Sounds to me like theres a blockage for sure

Forget all the fancy fuel aditives, they are no substitute for clean tanks and clean fuel

Now 4 layers of cloth rags, a old tee shirt folded over in a funnel and slowly poor your fuel back in, new filters again 

Now prime up and start

If it stops again, stop fiddling and spraying ether

Try starting the truck, while trying to start the truck look at the exhaust, is it smoking, if so what colour is the smoke ??

This gives you a hint of the issue 

 

Good luck

 

Paul

[MACKS]

I to think dirty fuel tanks,can u possibly find a used clean tank for cheep just run it home on one tank?

[67RModel]

On 9/22/2024 at 6:32 PM, alabamaslammer said:

Cranked it with ether and then it died.

 

On 9/22/2024 at 6:32 PM, alabamaslammer said:

I walked back to my truck, got a can of starting fluid, and she fired up with ether so I could pull her off the public road.

Absolutely under no circumstances should you use ether or starting fluid on a Mack ASET engine. It will wipe out the ceramic lifters before you even realized what you did. Big No-No.

Other than that it sounds like a classic fuel starvation issue. If it runs good for a while then it has compression so no issue there. Obviously there are a lot of electronics and an ECM involved on an ASET AI, which could be a culprit, however, from the story you tell it sounds like its running out of fuel. Any indication from the previous owner why they parked and/or sold it?

Edited September 24 by 67RModel

[Joey Mack]

NO ETHER!!!

[alabamaslammer]

Thanks. During bidding the fleet manager said it didn't run and had a bad shift pad. After arriving to pick up the truck, getting it running, and bringing a replacement shift pad, he said they parked it because it stopped taking gear up hill. I honestly don't know what that means. I told him the shift pad in it worked - or so it seemed - and he said maybe the batteries being dead reset it... Getting any information from him is like pulling teeth. I've pressed him a couple times firmly to just spill the beans to no avail. The last buyer backed out after arriving to pick up as it didn't fit on a low boy as it was too tall. The mechanic who used to work on it is out on sick leave with cancer, the guy who used to drive it died while I was there (they were loading bush hog onto a trailer one day to prepare grave site for his wife).. The route sheet in the truck was dated 2010, batteries were dated 2020. 

I appreciate all the insights and suggestions. I've ordered two honeywell 0-100psi pressure sensors (one for pre-pump and one post-pump), two 12v to 5v voltage regulators, sensor connector ends, two lcd digital voltage displays to mount in cab (5v =100psi, 4v=80psi, etc), 3 primary filters, 3 secondary filters, a replacement fuel pump (hopefully don't need) and a replacement fuel cap. My cap was covered in white chalky material - I believe aluminum corrosion - and I think it might have been clogged. I banged it on side of tank a few times after I noticed it but didn't think much of it, and didn't know fuel vent clogs can restrict fuel flow. The fuel cap might qualify as a crime scene and potential cause for lack of fuel flow from what I've read over past couple days. I wasn't able to find a 12v fuel supply pump that had a 1/2" line input/output and decided not to fool with it as I am concerned I'll just be installing a fuel flow restrictor. I tried calling around a ton of places in TN for a fuel polish but frankly I am a cheap bastrd and even if a company offered the service - which nobody does unless you own a million gallon tank farm- I probably wouldn't be interested in paying. My current plan is to remove the tank and pressure wash the inside along with all the lines and then blow them all out with air and let them sit in the sun. I'll save the diesel for fire starter for my wood stove this winter. Will scan the truck with vmac, clean tank/lines and blow them out, install pressure sensors, refill fuel, replace filters, bleed, crank and observe pressure gauges/computer. will also buy a crimper and bring some spare battery cables to replace the ends at the corroded post near the ecm. will check ecm connectors. need to check fuel return restrictor valve- need to get instructions to locate. observe lines for air leaks/collapsed sections/internal separation/flapping. will check turbo (it does not have vanes which I thought previously) find fuse box/check fuses. will also check air filter for blockages. The air filter housing was dented(/cracked?) and had trash jammed up all around it. 

I am trying to determine what size fittings I need for pre/post pump. Here are links to pump and fittings if anybody can eyeball or check theirs. The honeywell sensors have 1/8 npt male ends. Thanks guys. 

 

 

[JoeH]

Welcome to the MR688 club! I bought a 2003 MR688S with the AI350  almost 3 years ago and I love it! Except for the ride. It is rough on your back on highways.  Tires likely aren't rated for more than 60mph, I had one come apart when I was doing 68 mph on my way back to PA from Iowa after getting a new volumetric concrete mixer body put on it.  Personally I'd get the truck towed home, I wouldn't drive it.  

Fuses are all in the center console, there *should* be a decal in there telling which fuse is where, but I'm sure it's missing.  Worth it's weight in gold is a flashdrive, Mack part number 23-021. It's available through the Mack eMedia website.  I got it through my local Mack Dealer but I had to talk him into the EMedia site so he could see what I was talking about about.  Listed as a DVD, it's a program with wiring diagram for every Mack chassis model from like 2001 to 2021.  

You can use Killem, but that doesn't dissolve the algae.  You have some work to do to get clean fuel.  You could also have a piece of trash floating around in the tank, getting sucked into the pickup tube occasionally.  

Active engine codes can be pulled out on the fly by holding the set/decel cruise control switch down for a second while the main on/off cruise rocker is off.  It'll blink out a 2 digit code telling you what the fault is.  

I hope you got the truck for a steal, trash trucks of this vintage are mostly falling apart. We got lucky finding ours with good frame rails at 24,000+ hours and 414,000 miles.  We pulled the frame out of ours and separated/sand blasted/painted them to clear up the rust jacking.

[67RModel]

9 hours ago, JoeH said:

Personally I'd get the truck towed home, I wouldn't drive it.  

Yea I didn't want to sound like a $hithead but honestly after 3 trips from Georgia to Tennessee, the hotels, parts, Lost time not working and potentially breaking down half way home he'd probably be money ahead or money equal to just have it towed. Like what's your time worth?

[JoeH]

Id like to know what the intermittent codes are. Hook up your computer and look them up. If your vmac III software doesn't work, DieselLaptop's Diesel Explorer 2.0 program gets the job done for me. 

[Jody Scott]

Do you have a friend with a lowboy?

[JoeH]

47 minutes ago, Jody Scott said:

Do you have a friend with a lowboy?

Too tall for a lowboy, trash trucks are pretty well maxed out on 13'6".

[alabamaslammer]

I watched video when i unscrewed primary filter and you can hear a distinct vacuum release/air rush. Either vent cap is clogged and creating fuel lock/ vacuum, or pump sucking against clogged filter created a vacuum. Here's a photo of the scan with allison doc. I spoke with an allison tech who noted the check trans light should come on with key on engine off and then go out within 10 sec of cranking, so all good there. I will scan truck with usblink and vmac when i am there next.

 

Edited September 27 by alabamaslammer

[Geoff Weeks]

I used to have tank venting problems in the real cold temps (below 0 f) , the vent would ice over on the non-draw side and prevent cross-over. cracking the cap would allow the tanks to equalize, it was surprising that it would hold almost the full amount of fuel in that one tank, while the other was almost empty.

 Be sure that what you are hearing is not just the fuel syphoning back to the tank when the seal is broken at the filter head, there is no "foot valve" on the fuel pick-up in most all cases. If in fact it is a venting problem that is easy to solve.

[mrsmackpaul]

If it was me I wouldn't worry about what any previous owner says may or may not be wrong 

I can understand the previous owner doesn't want any involvement, just get it off their place

It is no longer their problem, it is now your truck, your problem 

All of that been said, maybe think about getting a jerry can and some hose and just run your supply and return out of that

If you can make the truck run fine from that, you know the problem is in the tank or the hoses connected to the tank

 

Paul

 

 

[JoeH]

I second the alternate fuel tank test. Throw a few gallons in a 5g bucket and dip the hoses in.  Put fresh filters on it and try running it.

[JoeH]

How many hours/miles are on this truck? Title says it sat for 15 years. That means they parked it in 2009??? It's a 2004 truck, if it got parked that young in its life id suspect this truck may have been a lemon... Doesn't mean we can't fix out whats going on, but it does give a little insight into things...

[JoeH]

It also means it's likely missing some software updates and recall fixes.  One example is coolant can wick along the coolant level sensor wires the the EECU and corrode the EECU pins.  There's a short jumper pigtail that has sealant embedded in the wire strands to fix this problem.

The diesel explorer program gives you a lot of live data while driving.  It'll tell you what your throttle position % is and what the output fueling is.

[JoeH]

Also being a 2004, this will have the AI350 motor, which uses restrictive exhaust manifold/turbo to create exhaust back pressure to feed exhaust back into the engine when an extra exhaust lobe on the cam bumps the exhaust valve open on the intake stroke.  Primitive EGR system that you can delete by getting the exhaust manifold and turbo from a pre-ASET engine.  2003 was the changeover year on this. So you'd want to target 2002 MR688 for manifold/turbo part numbers.

[JoeH]

Also not sure anyone's picked up on them, but those 2 dalmatians are good looking dogs!

[alabamaslammer]

Thanks. Truck had engine and harness replaced by mack dealership after top end let go. I called and got the detailed shop notes prior to buying it. Motor was replaced w/ reman at 92k miles. Odometer shows 108k miles. Kept eating through shift pads (known allison/wtec3 issue), packer floor replaced, fenders rusted out and she got parked. Yea I'm kind of in love with these ai's from what i've been reading. Slow and reliable. Like my 7.3s. Lots of potential mods for improvement. 

[JoeH]

Sounds like there's some unresolved lemon issues going on, it only lasted 16k miles on that rebuild til they got fed up with it. Hopefully some old timers on here will be able to chime in.  I'd get a hold of every Tech Service Bulletin you can get your hands on.

This engine should be CCRS which is Current Controlled Rate Shaping.  Basically the EUPs get fired in 2 phases, an initial one to start the burn and a second phase to complete the full injection quantity.  Pre CCRS trucks just fired the EUP in one shot. EUPs are not interchangeable. Heads are also different, the pre CCRS I believe used a leak off line from the heads, the CCRS do not.  

[alabamaslammer]

I will look into getting the tech service bulletins. Ive got all 16 wiring schematic pdfs for it, engine service manual and vmac diag manual. Would like to find MR series operators handbook if anyone has pdf copy (on ebay for 96 bucks...). Will be studying it all to get familiar.