Ford 850 Hyd problems

   / Ford 850 Hyd problems #1  

glweder

New member
Joined
Aug 14, 2008
Messages
10
Location
Grand Ledge, MI
Tractor
'57 Ford 850, '86 NH 455 SL
Hello,

I have a ford 850 that I love but for the last year has experienced intermittent hyd' leaks. And by leaks, I mean it pours! I took the lift assembly apart last year, completly cleaning out the resevoir, replaced any o-rings I could. I also rebuilt the hyd-pump. The problem started when I borrowed a friends tiller for some landscaping work, the tractor started leaking bad around the pump mount flange. I did all the above work but it continued to leak. This spring I used the tiller again and noticed it didn't leak at all. Fast foward to last week when I was using the tractor to dig some post holes; it started leaking like a mother... again. The leak is at the same mounting flange as before. Everything is tight and I don't see any cracks.

My guess is my some debrie has plugged something (I cleaned alot of gunk out of the reservoir) and the system is creating too much pressure?


Thanks for any feedback.

George
 
   / Ford 850 Hyd problems #2  
Hello,

I have a ford 850 that I love but for the last year has experienced intermittent hyd' leaks. And by leaks, I mean it pours! I took the lift assembly apart last year, completly cleaning out the resevoir, replaced any o-rings I could. I also rebuilt the hyd-pump. The problem started when I borrowed a friends tiller for some landscaping work, the tractor started leaking bad around the pump mount flange. I did all the above work but it continued to leak. This spring I used the tiller again and noticed it didn't leak at all. Fast foward to last week when I was using the tractor to dig some post holes; it started leaking like a mother... again. The leak is at the same mounting flange as before. Everything is tight and I don't see any cracks.

My guess is my some debrie has plugged something (I cleaned alot of gunk out of the reservoir) and the system is creating too much pressure?


Thanks for any feedback.

George

Is it leaking around the mounting flange of the pump??
What type of pump/system is it on that F850??

One thing I can imagine, is that if you have a piston pump/constant pressure system, with oil in the pump casing/housing, and the drain line from the housing to tank is restricted, a higher pressure in the housing will blow the shaft seal....
If this piston pump is way worned out, there will be internal leakage inte the housing and these 1/4" drain lines cant handle all that flow....

If shaft seal is blown, then this is your problem...

If this piston pump applies on your case, check shaft seal....check these drain lines, clean them, make sure they are not squezzed or bent...if drain are going through the filter, make sure filter is not restricting.....make sure reservoir vent is working....
Drain lines are sometimes designed to by pass filter of this reason....drain line HAVE TO BE VERY LOW, OR NO PRESSURE AT ALL....ONLY A FEW PSI AT THE MOST
 
   / Ford 850 Hyd problems
  • Thread Starter
#3  
Is it leaking around the mounting flange of the pump??
What type of pump/system is it on that F850??

One thing I can imagine, is that if you have a piston pump/constant pressure system, with oil in the pump casing/housing, and the drain line from the housing to tank is restricted, a higher pressure in the housing will blow the shaft seal....
If this piston pump is way worned out, there will be internal leakage inte the housing and these 1/4" drain lines cant handle all that flow....

If shaft seal is blown, then this is your problem...

If this piston pump applies on your case, check shaft seal....check these drain lines, clean them, make sure they are not squezzed or bent...if drain are going through the filter, make sure filter is not restricting.....make sure reservoir vent is working....
Drain lines are sometimes designed to by pass filter of this reason....drain line HAVE TO BE VERY LOW, OR NO PRESSURE AT ALL....ONLY A FEW PSI AT THE MOST

Thanks for the feedback: The pump is the piston style pump, and yes it is leaking around the mounting flange. When I rebuilt the pump I didn't notice any wear or play at all. I agree there must be a restriction somewhere, just not sure where to start. There is no filter in the system, so I'm guessing some junk is intermittently plugging something. I spent alot of time last fall cleaning crap out of the reservoir. but some obviously is still somewhere in the lines.
 
   / Ford 850 Hyd problems #4  
Thanks for the feedback: The pump is the piston style pump, and yes it is leaking around the mounting flange. When I rebuilt the pump I didn't notice any wear or play at all. I agree there must be a restriction somewhere, just not sure where to start. There is no filter in the system, so I'm guessing some junk is intermittently plugging something. I spent alot of time last fall cleaning crap out of the reservoir. but some obviously is still somewhere in the lines.


You have a piston pump...
Do you have that 3rd hose from the pump casing???
Thats is the drain line!!
MAKE SURE THAT DRAINLINE IS CLEAN, all the way from inside the pump casing to the tank, also allow no kinks or sharp bends...
If it is leaking now, you have to replace that pump shaft seal....
Next time you are ready to start up the pump, do not not have the drain line attached yet, and fill the casing with clean oil before starting up....NEVER DRY START A PUMP OR A MOTOR....when casing is filled to the hole, make an arrangement so you can collect 100% of oil coming out during 30 seconds of high pressure load on pump...that amount of oil will tell how worn your pump is....an ok pump should not leak more than some few cc of oil per minute....if a significant larger amount of oil is coming out during this test, something is wrong with your pump, either worned out or assembled incorrectly.....

Normal wear may be hard to detect for a non-professional pump "technician"...

The above test also apply on hydraulic motors...
Do all internal leak testing testing at normal operating temperture (viscosity reasons)....

BTW how old is this tractor?
 
   / Ford 850 Hyd problems #5  
Is it leaking at the 3 bolt flange? All that seals the pump to the hydraulic manifold flange is 2 square shouldered o-rings. Make sure that you have the right o-rings and that the 3 bolts are tight.

Please post pics if this isn't the problem.

Mike
 
   / Ford 850 Hyd problems #6  
I don't think you are familiar with the engine mounted hyd pump on an 850.. or at least it doesn't sound like it...there is no 3rd line.. there is a hyd manifold that runs from it tot he trans center feedthru lines.. at the hyd section there is a relief valve...

the pump is cam driven, and if it is gushing oil at the gear drive, I'd think a shaft seal was gone.

I included a exploded diagram of the pump

soundguy

You have a piston pump...
Do you have that 3rd hose from the pump casing???
Thats is the drain line!!
MAKE SURE THAT DRAINLINE IS CLEAN, all the way from inside the pump casing to the tank, also allow no kinks or sharp bends...
If it is leaking now, you have to replace that pump shaft seal....
Next time you are ready to start up the pump, do not not have the drain line attached yet, and fill the casing with clean oil before starting up....NEVER DRY START A PUMP OR A MOTOR....when casing is filled to the hole, make an arrangement so you can collect 100% of oil coming out during 30 seconds of high pressure load on pump...that amount of oil will tell how worn your pump is....an ok pump should not leak more than some few cc of oil per minute....if a significant larger amount of oil is coming out during this test, something is wrong with your pump, either worned out or assembled incorrectly.....

Normal wear may be hard to detect for a non-professional pump "technician"...

The above test also apply on hydraulic motors...
Do all internal leak testing testing at normal operating temperture (viscosity reasons)....

BTW how old is this tractor?
 

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   / Ford 850 Hyd problems #7  
I don't think you are familiar with the engine mounted hyd pump on an 850.. or at least it doesn't sound like it...there is no 3rd line.. there is a hyd manifold that runs from it tot he trans center feedthru lines.. at the hyd section there is a relief valve...

the pump is cam driven, and if it is gushing oil at the gear drive, I'd think a shaft seal was gone.

I included a exploded diagram of the pump

soundguy

I kinda started to suspect there was something wrong, and after a couple of Googles on Ford 850 pump...... could see they have history back in 1950's?? so it is a pretty old one then....newer piston pumps/motors are built with piston unit inside a casing.....Well OK, this is a forum and we all learned something hopefully.....:cool:

BTW from what year is this tractor??

Hope you get some help with your pump now....
 
   / Ford 850 Hyd problems #8  
I kinda started to suspect there was something wrong, and after a couple of Googles on Ford 850 pump...... could see they have history back in 1950's?? so it is a pretty old one then....newer piston pumps/motors are built with piston unit inside a casing.....Well OK, this is a forum and we all learned something hopefully.....:cool:

BTW from what year is this tractor??

Hope you get some help with your pump now....

It's not my pump.. though i do own an 850..... and 9 other various fords fromt he mid 40's and up

the ford xx0 series were model years from 55 thru 57.

soundguy
 
   / Ford 850 Hyd problems
  • Thread Starter
#9  
Is it leaking at the 3 bolt flange? All that seals the pump to the hydraulic manifold flange is 2 square shouldered o-rings. Make sure that you have the right o-rings and that the 3 bolts are tight.

Please post pics if this isn't the problem.

Mike

Yes thats exactly where its leaking. I replaced those o-rings and remounted it several times to make sure its on square and tight.
 
   / Ford 850 Hyd problems
  • Thread Starter
#10  
It's not my pump.. though i do own an 850..... and 9 other various fords fromt he mid 40's and up

the ford xx0 series were model years from 55 thru 57.

soundguy


My 850 is a 57'. Great tractor, uses alot of gas though. Soundguy you think the oil seal for the drive shaft is worn? I see it in my service manual and the instructions show the use of a set of special tools to remove and install the needle bearings and oil seal; do you know if this can be done w/o these tools?
Thanks for the help.

George
 
 
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