Just won a M1010

[TexAndy]

You could have been lucky like me and had the drive shaft safely inside the back.

 

[Keith_J]

That was a little work today...but the tank is polished clean. mkcoen now knows the feel of diesel sludge in his fingers .

There was this little plate on the frame flange, right over the gap between the cab and box. This is a reinforcement to handle the stress. It has a press broke edge where it meets the web of the frame. And this little edge inhibited all access to the top front bolt of the fuel tank bracket. And getting this bracket out is nearly IMPOSSIBLE. Then they HAD to use NyLok nuts . A tap cleared that up.

Then there is the reconnection of the lines. Chevrolet used about 6" of rubber hose, nearly impossible to reconnect due to the limited access afforded by the ambulance body. For the main line, I used all 1/4" extensions we had, 2 of mk's 6" and one of his 3" with mine and driver. This way it would reach from the rear.

The skid plate was a bit loose due to the forward stud breaking on removal. So I modified a hose clamp to be an adjustable strap, drilling 2 holes in it. One end attached to the bracket for the tank mud flap, the other end on a preexisting hole in the skid plate. This positively eliminated the rattle in the skid plate, something that would drive me nuts as well as causing wear. Simple, elegant and functional as the skid plate lacks outboard support.

The spring clips were also problematic due to proximity of the others but eventually

Now the North Dakota mud underneath? Highly abrasive glacial till. And without much clay, it just LOVES to drop off into eyes, ears and nose. I used a putty knife to loosen the stuff on the rail flanges, then shop vacuumed it off. There still is about 100 pounds on the undercarriage.

Finally, the fuel filter for the heater in the back was drained of its water, about full of it. The filter is cleanable, if you work with it. Very fragile as it is laminated rings of phenolic paper. The holder keeps it under compression. With this, the lines were also blown down from the engine compartment flare fitting caps, all the way back to the heater where there is a drain tee and ball valve. Perfect place to tap for an MBU fuel supply, just in case he wants to cook for an army

Now with a new main filter and the 9 gallons of decanted, clean diesel, it should make it to the local filling station. And a good, possibly locking cap?

This was quite a job, badly needed. And I was so busy my coffee consumption was delayed until after 1700. My Thermos kept it perfectly drinkable all day.

 

[mkcoen]

This would have been an impossible task without Keith_J. I owe him more than a pasta dinner for this one.

One more good day of work and a new driveshaft and we should have it moving under it's own power.

 

[CUCV85]

January 19th, 2010.

Almost makes me wish I'd a bought one of the new ones GM was disposing of back in West Virginia for $29,000 in 2007. Pretty much the complete truck from the factory except no light bar. The Army paid about $92,000 each for use in Iraq and for some reason the deal didn't go through...

And yes, no EUC from GM!
Cheers,

Kyle F. McGrogan

Pictures please

 

[CUCV85]

aux fuel pump running ( run a 24v jumper wire ), you can drain the tank out the back

If you get the aux fuel pump running ( run a 24v jumper wire ), you can drain the tank out the back of the truck. There should be a Tee and a valve to open under the rear fuel fired heater.

VERY GOOD TO KNOW

 

[Keith_J]

This would have been an impossible task without Keith_J. I owe him more than a pasta dinner for this one.

One more good day of work and a new driveshaft and we should have it moving under it's own power.

It was fun...well, all but the pain of GoJo on open cuts.

I looked on the MAC of the -20 and it shows 1 hour for fuel tank replacement? Impossible.

Now for the good news. Two parts:

To prevent the engine from running when priming after a fuel filter change, pull the pink wire going to the injector pump area.

There is a "water in fuel" sensor. As long as this light isn't on, the injection pump should have water-free fuel.

 

[ABN173]

First order of business (other than making sure it's running good) is to paint it back the 3 color camo. I like consistency in my fleet

Hmmm I like the 3-color camo too, but having served in Desert Storm as well as the current OIF rotations I am kinda partial to Tan CARC too.

Congratulations on the win though looks nice!
Dale

 

[Keith_J]

Stand by for good news...

 

[mkcoen]

IT LIVES!!!Bwahahaha

Okay, it's running any way. As a matter of fact, it's still running as I let it get up to operating temps before I shut it back down.

Thanks to Aboonski on his video on changing a CUCV fuel filter. I had heard horror stories about doing it but it was really a snap and started surprisingly easy after having dropped and drained the fuel tank.

Now to just get a new drive shaft and I'm heading down the road!

 

[Keith_J]

So the fuel pump MUST be good. No "water in fuel" light means we got all of the water.

Time to change your signature line

 

[mkcoen]

Time to change your signature line

To "almost driving?" Got to get that drive shaft fixed first.

 

[Keith_J]

You want me to give the brakes a looking over? 26k means they should be fine, if that is all highway. But if not highway miles, the rears could be toast.

These vehicles have a ride height proportioning valve so the rear shoes could be gone.

Probably due for a front bearing pack too. The rears are bath lubed so no service if they are not leaking. NAPA should have all parts.

 

[mkcoen]

What ever you're up for. I'm waiting for the glass guy today to do the windshield then I'm running over to NAPA for the basic maint items (oil, filters, etc). Already pulled the drive shaft so just need to drop it off tomorrow and hopefully get it back quick.

 

[Keith_J]

If you don't want to drive to the other side of San Antonio, Thrash is on West Avenue. They rebuild and balance. But they just might have one in stock.

 

[mkcoen]

Got the new drive shaft installed this afternoon, changed the oil, topped off all the other fluids and was ready to roll when Keith_J showed up. We decided to head out for a quick test drive and made it about a block without the transmission shifting once so turned around and headed back to the casa. A quick check of the vacuum lines showed why there wasn't much in the way of vacuum (all lines were completely rotted through). Down to the local NAPA for $3 worth of hoses and suddenly we were in business. It drives and shifts much smoother than my 1009 and the road noise is about half of what it is in the Blazer.

New problem is with the DUVAC. It is overcharging the front battery as is the case when these go bad. Keith is going to research the TMs to see if there is a work around short of shelling out for the battery conditioner. With the new windshield and drive shaft I'm already $450 more into the vehicle than I had planned on so need to be as cheap as possible to fix this.

 

[Keith_J]

I think I know how the Duvac works. The Leece-Neeville alternators are 28 volt, 100 ampere. The lower unit feeds into the 24 volt battery system directly while the upper alternator feeds into the Duvac which reduces the voltage to maintain the 12 volt subsystem, regardless of load. The voltage relay (to the rear of the Duvac) then controls each alternator independently to balance the charge.

There are 2 diodes in the WIRING which can fail, causing the top alternator to over-charge. I found one tonight, didn't have the TM handy to see WTH this thing was but I remembered the wire color codes...one or two are bound to be fried. Hopefully they aren't fried to the point of non-identification. These are simple to check and because they lack any real heat dissipation, are likely to fail. Good news is the fix should be under $10.

So this isn't a true 200 ampere 28 Volt system but a hybrid 28/14 volt, 100 ampere Frankenstein. Still a lot more than the other CUCVs.

I believe Sure Power Industries made the Duvac. Without pulling it, I don't know the model number and Sure Power only sells to distributors. They might have a replacement Duvac which would work.

Too bad the weather is going to go down in quality. And the garage isn't large enough for the M1010.

Gee, I just had a thought...the Duvac should have a MFG part number in the 34P. And a CAGE code. And the -P should also have specs for the diodes. Give me a break, it has been a while since I spun wrenches for Uncle Sugar. Thankfully the owner of this M1010 doesn't require me to file the paperwork.

HOLD THE PRESSES...and DO NOT RUN THE M1010!!

Review page 2-44 in the -34. Step 12. Sounds like this is just an adjustment. I remember seeing the adjustment screw on the Duvac is only sealed with tape. It could be over-adjusted or just never properly adjusted. This would be a cheap solution.

 

[lavarok]

A replacement DUVAC, if you can find one, will most likely cost as much or more than a solid battery equalizer. Your assessment of how the DUVAC works is partially correct. The system (DUVAC) is compromised of a voltage regulator and a batter isolator. It is supposed to provide both 28v and 14v when required. 28v is the default mode and there is a wire swap trick detailed in another thread that changes the default mode to 14v, credit goes to CUCVFAN for coming up with this trick. It didn't work for me, but it is worth a try.

If the sensing circuit is the problem and the rest of the unit is ok, then this wire swap trick may work. There is also a "TB" in the resource section that details a wiring enhancement/change from the factory setup. This is also referred to as the orange wire mod.

Link to post regarding "swap trick":

http://www.steelsoldiers.com/cucv/8627-m-1010-charging-system.html#post77937

I have attached the DUVAC user guide and the orange wire mod TB. Right click and "save as".

Good luck!

 

[Keith_J]

Cool. I think from the measurements I made tonight the system is working, it is just working too well, overcharging the front battery. I could smell the acrid stench of battery boiling (actually outgassing, it was barely warm to touch). The -34 TM detailed adjustment, showing the front battery voltage to be too high when the adjustment screw is over-adjusted. The TB shows this adjustment screw to be totally backed out. But this Duvac has the factory tape over it.

What I think happened is somewhere along the way, the Duvac was replaced with one fresh out of the box and DS (probably DOL) just threw the new Duvac on, not referencing the TB or TM for proper operation.

Yes, the TB has been applied, as I have seen the cut wires. This is getting interesting, detective mechanic work.

 

[mkcoen]

I don't think there is a new fuseable link near the DUVAC as shown in the TB though. Could be they started to do it but never completed it. There is also the "Master Shutoff" switch under the dash that isn't connected to anything.

I pulled the negative battery cable last night so there wouldn't be any juice to the system. Things would have been so much easier just buying an new F150

 

[lavarok]

Keep in mind, the Leece Neville (LN from here on) alternator cannot output under 18v on it's own. The regulator is supposed to pulse the field circuit on the LN to achieve a lower voltage and not cook your battery. I could never get mine to work correctly so opted to replace the DUVAC completely with a battery equalizer. I think you will save time and money if you do the same.

However, if your determined to try and make it work then perhaps my old parts will help. I believe I have both the regulator and the isolator. If you cover shipping on a flat rate box, I'll send them to you. PM me if interested.