cat 941B loader governor problem

[kshansen]

Info can be found in the 3304 Vehicular Engine Parts book up to s/n 80H5703-up at which point you have to refer to the 941B Parts Book. Have to go the the Service Manual to get any meaningful information.

Must be I'm just missing something here, does that page show up on SIS someplace that I just fail to see?

 

[Bluox]

N&P
clean the dirt off your pump then take the 2 bolts off the plate the oil line is hooked to and replace the diaphragm on the plunger. you may have to replace the inner seal on the throttle shaft.
good luck
Bob

 

[Old Magnet]

Must be I'm just missing something here, does that page show up on SIS someplace that I just fail to see?

I don't know about what's in SIS, the list I posted was copied from the front of the 78P 3304 Vehicular Engine Parts Book.

 

[kshansen]

I don't know about what's in SIS, the list I posted was copied from the front of the 78P 3304 Vehicular Engine Parts Book.

Well just for kicks I did save that page to at least three different places for future reference!

I know I have seen charts like that or maybe it was that one1 If anyone does know of some place on SIS a chart like that is available for this or some other machines please post it here. Some times information that was in a print copy seems to get missed in the conversion to online information, or just gets files someplace not readily found!

 

[Nick & Pat]

That should be a sleeve metering pump. If fuel is leaking from the governor control shaft it's because the inner seal is leaking. The compartment behind the outer seal should be dry.

If you get no replies send a PM to HEF member "thepumpguysc". He's the resindent FIP expert.

just checking to see if "thepumpguysc" is a correct member name
is there a "c" at the end?? or is it just "thepumpguys"

N&P
clean the dirt off your pump then take the 2 bolts off the plate the oil line is hooked to and replace the diaphragm on the plunger. you may have to replace the inner seal on the throttle shaft.
good luck
Bob

i took the top plate off and saw the diaphragm and it seems ok
also took out the shaft (some manuals call it a plunger) with the notch / slot in it and spring, and cleaned it up because it seemed dirty
it seems that the governor control shaft plates are engaging and prevents the throttle control to move beyond half way (the throttle position when starting)

 

[Nick & Pat]

Not familiar with that particular pump but did find this that might be of some help, will keep looking as I have time.

yes sir
that is the exact fuel pump and governor i have
i checked out the diaphragm plunger and spring and they seem ok to me

 

[kshansen]

just checking to see if "thepumpguysc" is a correct member name
is there a "c" at the end?? or is it just "thepumpguys"

/QUOTE]

the correct name is
thepumpguysc

 

[Old Magnet]

If you pull the control shaft, linkage parts drop off the shaft.

 

[kshansen]

Just a word of caution for the OP, that shaft assembly can slide out if you remove the side cover and the part circled in red will fall off the end of the shaft inside the governor. To replace the seal that is inside the housing in the area where #5 is pointing you will need to remove the governor from the pump. If not installed correctly it can have serious problems when starting engine.

 

[Old Magnet]

Did some more checking..
Apparently that unit is set up with an oil pressure safety shut down, not an Air Ratio Controller.
Information is vague on internals but if the diaphragm leaks oil could possibly migrate into the governor and pump.
Still would have to get by the inner control shaft seal to leak out the outer control shaft seal. Seems pretty much as Bluox describes.

 

[kshansen]

Cat sure seems to be making this one difficult to comment on without having physical parts in hand! Below should be a cross-section view of the back of the governor on this engine. I've not found a description of operation for this set-up but it appears that oil pressure works on the diaphragm #4 which in turn pushes down on plunger #5 compressing spring #6. What I'm not seeing is how this controls the position of the two plates # 7 that are keyed to the governor shaft.

But even with that confusion if the diaphragm is operated by oil pressure and it is leaking I would say that it is not going to make plunger #5 do it's job and at the same time fill that housing with oil causing the outer seal #10 to leak.

As I recall the section of the other sleeve metering pump governors the area where the plates #7 are located is dry, not in the oil, like the rest of the governor parts to the left in that picture I'm wondering if the diaphragm is the main part of the problem both with the operation of the engine and the oil leaking around the shaft.

Note that if one decides to open housing up by removing cover #9 I would be sure to hold in on the shaft to prevent the inside parts #1, #2 and #3 from dropping off the shaft inside the governor.



Some numbers that might help if attempting to remove covers and diaphragm:
#4 was a 4N0610 that changes to 5N2487 diaphragm
#10 seal part number 4N2786
#13 Gasket part number 4N0402

 

[Old Magnet]

Interesting in that there is no part number call out for the inner control shaft seal. Not just for the 941 but for any of the 3304/3306 governors. Just assume it is the same as the outer seal.

I'm thinking something goes in that notch in rod 5 and has nothing to do with the #7 plates. One of the pump governor combinations shows a lever and bolt (in phantom view) in that vicinity. Maybe that's the connection?

 

[kshansen]

Interesting in that there is no part number call out for the inner control shaft seal. Not just for the 941 but for any of the 3304/3306 governors. Just assume it is the same as the outer seal.

Well if you look at a different view where it shows the side view of the pump there is an arrow pointing to the inner seal but you have to know where to look to find it item #7 and yes it's the same part number:

 

[Old Magnet]

OK, just seems it would have been easier to call out quantity -2 in the parts list.

Here's what happen to the inner parts when you pull the control shaft....

 

[kshansen]

OK, just seems it would have been easier to call out quantity -2 in the parts list.

Here's what happen to the inner parts when you pull the control shaft....View attachment 224626

Agree sometimes wish the guys putting together parts books actually knew what the parts did!

Also like that picture showing the bits laying in the bottom of the housing. Helps make my point about "NOT REMOVING THE SHAFT!"

I suppose if someone did screw up like that and then tried to start the engine it should not overspeed but if one of those bits did manage to fall into some other moving parts it would not be too pretty. At least as I recall the flyweights have a tin can covering them so you might get lucky!

Saved that picture for future reference!

 

[Old Magnet]

Still digging for info.
Got a few more tid bits from a 4Bxxxx Industrial Engine Parts Book.
Looks like linkage between speed limiter plunger and control shaft is through that flange arrangement sandwiched between the two plates. Can't get an image in my literature.
The outer shaft seal has the lip facing inward (cancels some former advice I got)
At this point I'm ready to conclude that this is in fact a speed limiter only , not a shut down device.
I'd say it was to function like the speed limiting plunger on the compact scroll pump that proceeded the sleeve metering version. Just limits speed until/unless engine oil pressure is obtained.
Need to actually get one apart and pay more attention to the limiter device which I have not run into before.

 

[Old Magnet]

Here's are matching lists for the 3306, also helps define change from D333c to 3306

 

[Nick & Pat]

Here's are matching lists for the 3306, also helps define change from D333c to 3306

View attachment 224661 View attachment 224662 View attachment 224663 View attachment 224664

engine is a 3304 not a 3306

 

[Nick & Pat]

Still digging for info.
Got a few more tid bits from a 4Bxxxx Industrial Engine Parts Book.
Looks like linkage between speed limiter plunger and control shaft is through that flange arrangement sandwiched between the two plates. Can't get an image in my literature.
The outer shaft seal has the lip facing inward (cancels some former advice I got)
At this point I'm ready to conclude that this is in fact a speed limiter only , not a shut down device.
I'd say it was to function like the speed limiting plunger on the compact scroll pump that proceeded the sleeve metering version. Just limits speed until/unless engine oil pressure is obtained.
Need to actually get one apart and pay more attention to the limiter device which I have not run into before.
View attachment 224655 View attachment 224656

thank you so much for your input

 

[Nick & Pat]

Agree sometimes wish the guys putting together parts books actually knew what the parts did!

Also like that picture showing the bits laying in the bottom of the housing. Helps make my point about "NOT REMOVING THE SHAFT!"

I suppose if someone did screw up like that and then tried to start the engine it should not overspeed but if one of those bits did manage to fall into some other moving parts it would not be too pretty. At least as I recall the flyweights have a tin can covering them so you might get lucky!

Saved that picture for future reference!

thank you very much for your input