May be someone

[long-cours.62]

here have this information :
I am trying to find a vue "éclatée" ( sorry don't know the term in English)

for "fuel transfer pump" on the Caterpillar C12.
The only drawing I have it is below , and when I ask to Cat a vue "éclatée" and/or "section" they send to me ...the drawing. below you can find it on "parts Manual".


The second view it is only to show what means "vue éclatée"
If someone have that for the pump ...welcome !!
Because I want understand something concerning this pump

 

[ranger58sb]

We'd maybe say "exploded parts diagram" or similar.

-Chris

 

[Bmarler]

Yep,
Exploded view or expanded view.
Also try assembly drawing.

 

[long-cours.62]

Thanks

Yep,
Exploded view or expanded view.
Also try assembly drawing.

but I ask to the main importer in France, it is easier for me
But when I ask for get an exploded or expanded view they send to me the normal view we can find in the spare part manual.
I check also with one branch of this importer, he type on the computer and got ... only the normal view
Because I remove the "discharge valve " who open around 8 bars to see his condition and eventually clean her.
Put her back , ok no problem .
But I don't know the Principe of this valve.
For example some security valve pressure you have the 'bolt" a "spring" and the spring push on the top of the valve (like for example the oil pressure valve on engine say OM636 Mercedes.
On this Cat one you have :

the "bolt" , a spring but the mobile part is not a "valve" but something like a pencil lead who move in the center of the spring. The spring do not apply pressure on it. And I am curious to know it the working principle.

 

[Bmarler]

but I ask to the main importer in France, it is easier for me
But when I ask for get an exploded or expanded view they send to me the normal view we can find in the spare part manual.
I check also with one branch of this importer, he type on the computer and got ... only the normal view
Because I remove the "discharge valve " who open around 8 bars to see his condition and eventually clean her.
Put her back , ok no problem .
But I don't know the Principe of this valve.
For example some security valve pressure you have the 'bolt" a "spring" and the spring push on the top of the valve (like for example the oil pressure valve on engine say OM636 Mercedes.
On this Cat one you have :

the "bolt" , a spring but the mobile part is not a "valve" but something like a pencil lead who move in the center of the spring. The spring do not apply pressure on it. And I am curious to know it the working principle.

Without seeing the valve in person I’d only be guessing. But, if there’s a spring, it must be doing something. You mention 8 bar cracking pressure, and a small pin in the spring. With the “bolt” secured, it must be locating the pin in an orifice, and the spring is controlling the cracking pressure. There has to be some moving part that you just aren’t seeing.

 

[long-cours.62]

Without seeing the valve in person I’d only be guessing. But, if there’s a spring, it must be doing something. You mention 8 bar cracking pressure, and a small pin in the spring. With the “bolt” secured, it must be locating the pin in an orifice, and the spring is controlling the cracking pressure. There has to be some moving part that you just aren’t seeing.

Probabely, it is why I am in search of this type of view
But for the moment I don't understand the principe.
For example for injecter or injection pump ( before électronique and comment rail ) the "spring apply the pressure on the "valve" "pin", May be the pin is not the "valve"? But sure this "pin" move because one end is steel coloris and another end "shining" like métal who move.
May be I am stupid But I like understand , I could also said it work why questioning

 

[Nick F]

The fuel pump is "Item" 2 in the parts list ("Ref" in this list). The list does not show the components of Item 2 - it is only sold as a complete "assembly". It is normal that the supplier does not show you the internals of an "assembly".

If you are very curious, disassemble the fuel pump and make your own "exploded view". Post the view here and lots of people will try to explain how it works.

Just be sure that you can re-assemble the pump !

 

[Bmarler]

I found this utube video of your pump:

The spring and pin are indeed a pressure regulator. If your spring is not acting on the pin there is something wrong with it.

 

[long-cours.62]

Thanks for the video,

I found this utube video of your pump:

The spring and pin are indeed a pressure regulator. If your spring is not acting on the pin there is something wrong with it.

When I remove the bolt I have the spring in the spring something like a "pencil lead" and not the "valve" we can see on the film (may she stay in the housing ) but I don't understand the use of this "pencil lead" .
But not pressure problem and start in 1 second.
The only problem I had when we bought the boat it is the second valve relief (show in first on the video) who don't work well ( must open at 4 bars) and our pressure fluctuate. Change this valve ( 85 €!!!) and work fine .
Thanks again for the video

 

[Bmarler]

I have to assume the pencil lead you refer to is in the center of the valve plunger. My best guess is, if the plunger travels too far against the spring, the center pin will hit the top of the bolt head and limit the flow by partially blocking the holes in the plunger.

 

[long-cours.62]

Thanks, this explanation seams logic one.
I feel less stupid this evening than yesterday I learn something...unfortunately it will not compensate all i forgot duri.g the same time :-(