955H 60A12813 Governor Limiting RPM

There is usually a low oil pressure switch that will not let the rpms rise until there is oil pressure
Chuck C

Not a switch exactly but a plunger on the back side of the governor that restricts the opening of the throttle until minimum oil pressure is met.
What model wheel loader did the fuel pump/governor come from? I'm having trouble finding a 8M3906 or 9M3906 governor group.

Guys,
Upon closer inspection, governor part number is 9H3906

Did model 950 use this part number (ever)?

Eldon

So your saying both governor housings have a 9H3906 part number?
The governor group number for the 955 is a 9M4678
The governor group number for the 950 is a 1S0720.

The 9M4678 uses governor spring 8H9219
Rack setting 0.070" for 100 hp.

The 1S0720 uses governor spring 7M7721
Rack setting 0.095" for 125 hp.

Edit:
A check of the 955 parts book shows 9H3906 to be the injection pump housing group number.
I don't have a 950 parts book to compare.

Check the group number for the 944A 43A series wheel loader, they were same h.p. spec as the 955H.

Hi Team
scan below is likely the Rack Limiter as is fitted to a Compact Pump that would likely be fitted to this machine.

As OM said it is tucked away at the inside face of the Gov Housing close to the engine--may have to remove the Gov. Hsg. to get it out.
Sometimes the pistons could get gummed up with sooty oil residue or worse still metal flakes from a failed engine component.

Check that the Gov. Housing to Injection Pump Housing Gasket has the required lube oil pressure passage hole in it.
Some units without the limiter may not have had the hole in the gasket--too long ago now to recall for sure.
Gasket P/No is likely 7L0552 as I do not have a Parts Book for this machine.

Also may I suggest you check your oil pressure to be doubly sure, these things do not require a very high of a pressure to retract the piston unless the Gov Control is really wedged hard against them.

As an example from my experience of these things, sometimes for an old hard starting engine you needed to wind the engine over to build oil pressure before you can get enough fuel injected for a cold start--as said, you needed to ease the Gov Control pressure to get the Limiter Piston to retract to allow you to then get to full fuel to get the engine to fire off.

An earlier type had the Limiter in the Rear Gov. Cover and it requires an external tube and fittings to take the oil pressure from the bottom of the Injection Pump rear flange back to the said Gov. Cover for this type Limiter to operate.

You can see how important a correct Parts Book is to go with your given S/No, I guess you are trying to locate one
Hope this makes sense.
Cheers,
Eddie B.

All the governor to pump gaskets are the same for the 60A series. Gasket part #8H9223.
The rack limiter plunger is fed with and external line from the injection pump to the cover that has the plunger mounted to it.
Early units prior to 60A6231 did not have the plunger feature.

Guys,
I sincerely appreciate your comments and willingness to assist.

New info...
The governor and fuel pump housing (from what I was told came off of the wheel loader) does not have the tube from the injection pump housing to the rear cover of the governor....meaning the wheel loader was using an earlier version of a governor, similar to or the same as 8H2862.

Next, I will closely examine governor for exact part number and provide a picture or two of what is actually present.

Thanks again.
Eldon