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Discussion Starter #521
Looking great. Yeah, vacuum assist power brakes are no fun without the vacuum. Broke a belt once on the vacuum pump on my 7.3. Very scary when you hit the pedal and there seem to be nothing there. Need a strong right leg to bring it to a halt without the assist.
Thanks! I got a fair amount experience with un-boosted manual brakes with this truck due to the old gasser V8 having a habit of exploding once the common cylinder-liner issue started to rear it's ugly head.
 

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Discussion Starter #522
First drive out of the shop after 2+ years & first time moving with Cummins diesel power! More video to come, just wanted to get something out while I continue the road-worthiness prep & get video edits completed.


Today I'll run a temporary wire back to the tail lights & add a proper start/kill switch, so I can hit the road!
 

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Discussion Starter #524
It's alive and mobile. Doesn't that feel good.
Long time coming, & best feeling I've had in a while!


I'm getting ahead on the final touches for the road testing now, starting with safety stuff like: reliable throttle cable lever/bracketry, brake lights that actually function (all the OE wire's been stripped from the entire body in preparation for a full rewire job), engine shut-down solenoid, etc.

Here's the final throttle cable setup with modified lever + new bracket, & I may add a secondary return spring + cable clamp, but for now it seems to function as I'd expect:


The comically long shifter that came with the transmission is now cut down ~3" so that 2nd gear doesn't wedge against the steering wheel. I'll most likely be building a "remote" linkage style shifter setup to sneak under the original dashboard & to move it to a more ergonomic location, but this'll do for now:


It's feeling a bit rat-rod in here with the drivetrain guts spinning around in full view... not mad at the view & wondering if a clear plastic (thick though!) cover for the tunnel would be worth the trouble. And let's not even get into how dumb I felt when I couldn't get it to move for a solid few minutes on the maiden voyage because this transfer case shifter was in nuetral:


I threw together a temporary setup for the gauges I figured were most important for the initial shakedown testing runs, with exhaust gas temperature coming in a close third, but for now these should keep me safe:


Speaking of "idiot proofing" here's hopefully enough for warnings to keep me paying attention to which pump I'm at when I'm grinning like a doofus at the fuel stations:



Heading out now for some proper road testing & rowing thru the gears for a good shakedown, so excited for some more seat time in this rig :)
 

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Discussion Starter #525
The shakedown drive went really smooth for the first handful of miles yesterday, but came to an abrupt halt after out of nowhere the engine developed what I guess I'll call a "hanging throttle". It's strange, ran so smooth all thru the gears for a good ~30 minutes.

Now it will usually idle okay when I fire it back up, but the moment I give it any input it ramps up RPM until rev limit or I intervene. It's not running away, because the governor is doing it's job & keeping RPM from going to the moon, & the shutdown solenoid cuts fuel quickly like it should. Linkage, cable, & pedal are not to blame because with or without them connected it will "hang". It doesn't smoke either white or black, so I'm ruling out an injector sticking, especially since even when it's ramping up RPM it still runs so smoothly. Wastegate seems to be operating as it should & no oil where it shouldn't be in the exhaust/intake/charge pipes, so I'm confident the turbo side's not to blame.

Best guess at this point is something's gone wrong in the AFC / Governor housing. Perhaps I have something set wrong in there after all the mods I did way back when it was on the engine stand...? I'll tear into that part of the p-pump & check all my baselines & be sure there's no corrosion or anything "off looking" inside since it did sit around for so many years after all. I guess I probably should get more than the oil pressure & water temp gauges hooked up now too (EGT, Boost, RPM, etc), just so I can see more of the health of things inside.

Going to dig in today & report back, hopefully it's just something stupid I've overlooked.... I want to drive it more so bad, the torque & response was fantastic!
 

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Discussion Starter #526
Well I found the failure & it was in the area I expected... but NOT the part I expected!

Don't have a clue how it ended up broken, or honestly what exactly to call the part, so for now I'll call it the "throttle arm". It's buried enough in the governor housing that I must've looked at it a dozen times before I spotted the lower "Y" shape was completely missing one half that rides on the pin at the bottom. Here's hoping I can find the part number or maybe find a used part etc during all this. I'll get better pictures once I get that housing apart, but here's the best diagram I could find with markups highlighting the broken bit:

 

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Good luck trying to find that part. Unless you could locate a used governor assembly your only source will be Bosch. That part 21 is called a link fork. Bosch part number 2 421 933 191. Actually found one of those listed on ebay for $354.90. OUCH! It's not going to be a cheap repair. You'll probably need a set of gaskets when you tear the governor assembly down. Not sure if you can make the repair without taking the pump off the engine.
 

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Discussion Starter #528
Ah yeah that's the conclusion I was coming to as well, seems most likely it'll be easier to find another used pump to strip of it's governor housing parts than find the new parts for $$$.

The disassembly with the pump still attached wasn't near as bad as I was preparing myself for. I was able to get at all those shallow head torx bolts fairly easily after removing the lift pump's output pipe & filter, just the lower engine-side bolt was kind of tricky. I guess a "silver lining" to it all is that I'm finally getting a chance to better familiarize myself with the p-pump's inner workings:


I found that 2421933191 part number too, which covers that whole assembly, and the specific individual part from that assembly that failed in mine is called the "fulcrum lever", seen here with one half of it's yoke broken clean off:


The worst part of all this isn't even the time/cost... it's the how. Can't for the life of me see how it broke like this, other than a crack from it's past life that's not reared it's ugly head until it had an actual load on it after nearly 4 years of sitting. No telling yet, needs a bit more head scratching:


I had my fingers crossed that the broken off piece missed everything because I had not heard any crazy sounds (although when the engine stuck full throttle it's hard to hear much of anything) and I have thankfully not found much of any metal chunks or shavings. BUT then I rotated the governor flyweight assembly around and spotted the other spring had clearly punted that broken piece at some point... look at that bend! So much for just replacing the 1 broken fulcrum lever:


I was real pissed off at first when I found all the damage... but I'm just too excited to drive it again to let it slow me down at this point. On to the parts hunt & repairs!
 

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The "Like" button just does not seem right for this. We need an "Ouch - That hurts" button. Good troubleshooting.
 
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One thing about it, that portion of the governor assembly should be the same on 4bt, 6bt, or 6ct P7100. Unfortunately, you probably aren't going to find a used pump for less than the cost of that part. Used 4bt P7100 is kind of rare. There are some used ones on ebay for a tad over $1600. They just aren't very common. If you could find a pump shop that had a scrap P7100 that might be a possible. '94-98 Dodge had them as well as commercial 6bt's. I believe the 6ct had the same governor assembly but you'd need to check for sure.
 

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Discussion Starter #531
Ouch for sure! Was hoping for an issue a little less "metal crunchy".

I am very thankful for choosing the Cummins over the TD5 from an overseas Disco... would be in loads of trouble if something like this happened with an engine like that.

I did loads of calling around & found a local pump shop that has cores they offered to peel parts from to help me out, so I'll try that avenue before looking into new parts (especially after the prices I was hearing!). I feel like I'm pretty lucky to not have a pump full of metal shavings, or even a cracked housing for that matter! Other than a couple big metal bits too heavy to flow into bad places, & a scratch on the inside of housing, would say I fared well all things considered after a failure like this:


The governor's flyweight assembly came off WAY easier than I expected after the initial look-over & after reading things online. I did have to whip up a custom tool from a spare socket in order to get into that notched taper nut that clamps it onto the camshaft. I thought of trying to repair/replace individual parts of the flyweight, but it just seems to damn risky given the importance of this thing's job. Best to replace the whole flyweight as an assembly I think. Here's a good look at that jacked up spring stud:


I think getting all this apart right on the engine was fortunate, should be able to get it all buttoned back up fairly quick ?
 

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What the heck happened to the governor springs? Were they a part of this disaster too? One thing about it, you're getting plenty of experience on the internal workings of the P7100 governor system. Don't know that we've had another member that experienced that failure. Parts inside that pump are built to extreme standards and don't generally fail. You sure are lucky it didn't ruin the case. Are you thinking of getting a complete used governor unit and transfer your new springs into it or just replace the broken parts in yours?
 

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This happens more than you might think. I have a core pump here that also has a bent gov stem on one side of the weights but it did break the housing. In your case, the fork broke for some reason. Not the norm at all.

Most damage in gov assembly is caused by people dropping a shim or screw or a spring while messing with the gov springs or camplate.....if they don't fish it out ( which isn't easy & sometimes impossible unless pump is torn down ), then they either try to rotate the engine over by hand trying to get a pencil magnet deeper into pump or say screw it & put back together & start the engine, hoping everything will be ok. The lose part migrates between gov weights & housing & damage happens. Some try bending the gov spring stud back straight but that is just a more expensive bomb waiting to happen.
Tinker is doing it right & got very lucky the case didn't break. No need to replace whole assembly as any Bosch shop will be able to replace with good used parts/pieces to keep costs down.
 

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Discussion Starter #534
What the heck happened to the governor springs? Were they a part of this disaster too? One thing about it, you're getting plenty of experience on the internal workings of the P7100 governor system. Don't know that we've had another member that experienced that failure. Parts inside that pump are built to extreme standards and don't generally fail. You sure are lucky it didn't ruin the case. Are you thinking of getting a complete used governor unit and transfer your new springs into it or just replace the broken parts in yours?
That governor spring appears to have had contact with the piece that broke off my fulcrum-lever & bent the stud + large outer spring.

That's similar to what I was hearing from the shops I called too, that even in the rare occurrence when one of those parts fails it's usually followed by a full self destruction of the pump.... I got pretty luckily unlucky!

I'm going to replace that broken lever & the complete flyweight assembly just to be safe in the case that more is bent than appears to the eye. I have my engine at TDC with timing pins engaged, & thankfully that flyweight assembly keys into the damper + timing-arm on the cam, so I can keep everything timed without removing the whole damn thing.

Should be able to get out of this for just a few hundred $ and a week or so downtime. Whole lot better than I had prepared myself for when I first spotted the damage!
 
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Sometimes the bad luck turns out to be not so bad. Like Mark said, you're lucky the disaster wasn't a major one. You'll also need to get a gasket or two which shouldn't be a problem.
 

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Discussion Starter #536 (Edited)
Right! And absolutely, bullet dodged I think.

The pump shop that my local Cummins hub referred me to (Diesel Injection Service LLC) hooked me up with all the parts I needed right after I just walked in for just over $300 ...which was a HUGE sigh of relief after what I had feared it could cost.

Brand new used flyweight assembly + fulcrum lever, a replacement 4K spring kit (in case an inner spring's bent too), & a governor housing gasket to keep all the schmoo in where it belongs:


(+a reminder to check the end of the pump-cam still has the shim in place under the slotted nut)
 

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Hate to be the bearer of bad news. I noticed the Pacbrake 4k gsk. Pacbrake makes great brakes but a poor GSK. Lots of complaints on the 6bt forums. Touchy/bunchy rpm complaints.
 

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Discussion Starter #538
Hate to be the bearer of bad news. I noticed the Pacbrake 4k gsk. Pacbrake makes great brakes but a poor GSK. Lots of complaints on the 6bt forums. Touchy/bunchy rpm complaints.
Crap! I had not heard of this. Thankfully at this point I'm getting pretty good at swapping springs. Do you have a recommendation for a more reliable GSK?
 

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That pump shop should be on your Christmas list from now on. If you'd gone down to Bosch to buy all those parts you'd probably have spent a couple thousand $$$. On the governor springs, do you really need 4000 RPM? Normally, most use 3000 RPM. The kits are often found for 4000 but you don't have to use the extra spring. Most of the running time is probably spent in the 1700-2000 RPM range.
 

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Discussion Starter #540
That pump shop should be on your Christmas list from now on. If you'd gone down to Bosch to buy all those parts you'd probably have spent a couple thousand $$$. On the governor springs, do you really need 4000 RPM? Normally, most use 3000 RPM. The kits are often found for 4000 but you don't have to use the extra spring. Most of the running time is probably spent in the 1700-2000 RPM range.
Oh yeah, they are on my list of places to visit & people to thank for sure!

Need? Nah probably not, but I did install the important valve-spring supporting mod. Originally I installed it as a "future proofing", since I know my habits & figured a built engine + compounds was in this build's future before too long
 
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