Jd 300 b backhoe

[Boobakar]

1978 jd 300b backhoe worked great, then... Got stuck in mud, got it out .....now: tractor was fine with hydraulics for ten minutes after mud... Everything was fine... Wouldn't move back or forward and then no hydraulics for backhoe and bucket ... Changed both filters, cleaned tranny screen and it made no difference. I am trying to figure out where control valve is in front hydraulic pump. could it be bad? Any help is appreciated ! Thanks....

Noise was right below seat probably two feet forward , more on left side, and was hammering ..what is an isolator and how to check them?

HHydraulics kept working for no more than 30'minutes total after losing tranny.. Tranny had loud hammering noise when started to not work...I think it's a closed system and the tranny pump provides pressure to front pump? I only know so much about it.. Thanks for your help, I miss this machine tremendously...

 

[jd40203020]

If this is anything similar to a 410-b you
probably sheared the clutch disk off from
the splined hub. It will need to be split
to fix this and make sure you get the new
style clutch disk with springs in the hub
to hopefully prevent this from happening
again.

 

[Tx Jim]

Easiest thing to check 1st is the front pump drive coupler to be sure it isn't stripped out & to be sure hyd pump shaft is spinning with engine.

 

[JDemaris]

Sounds like maybe your trans pump is no longer
turning. If your main pump quit turning -it
would have NO effect on your wheel drive and
trans. If the trans pump stopped turning -you'd
eventually lose all hydraulics and wheel drive.

Trans pump need not supply oil with any
pressure to the main front pump. Just has to
deliver oil and keep it "wet."

I have a 300B also and have the complete OEM
Deere tech manual in PDF. If you want me to
post any sections of it here - just ask.

 

[JDemaris]

Some tech info from the manual. Much depends on
which clutch setup you have in your 300B. Several
versions were used. If the center hub tore out of
the clutch disc or that disc was slipping you
could lose all hydraulics and wheel drive.

Also - pump drive in front of the engine also
varies by serial # of the 300B.

 

[Boobakar]

u still have that tech manual? Anything on cleaning carb? Mine starts for 2 sec then no gas...thanks, Josh

I have a 300B also and have the complete OEM
Deere tech manual in PDF. If you want me to
post any sections of it here - just ask.[/quote]

 

[Boobakar]

(quoted from post at 10:30:48 01/25/20) u still have that tech manual? Anything on cleaning carb? Mine starts for 2 sec then no gas...thanks, Josh

I have a 300B also and have the complete OEM
Deere tech manual in PDF. If you want me to
post any sections of it here - just ask.

/quote]

I need carb adjustments section? Thanks

 

[TM1010]

Just like TX Jim said, on my 300 it started making a loud grinding sound and just faded away, after that it had no hydraulics. The splined coupling between the pump and engine had stripped out. I'm glad that the pump wasn't bad.

 

[TM1010]

I forgot to say, after my coupling went out, I had no transmission forward or reverse. Mine has the reverser.