John Deere 6620 no hydraulics LS

[CHendrie96]

Having issues with me 6620. Has been working fine however whilst driving round the hard suddenly steering went notchy then nothing. Have got no hydraulics at all however if I coax the rear lift arms to raise (by sharp rev of engine) I can get a spool to pump and the hydraulics work whilst the hydraulic load is there. Guessing there’s an issue with LS and have been told to look at brake valve LS. Any advice appreciated.

 

[johndeere6140r]

Having issues with me 6620. Has been working fine however whilst driving round the hard suddenly steering went notchy then nothing. Have got no hydraulics at all however if I coax the rear lift arms to raise (by sharp rev of engine) I can get a spool to pump and the hydraulics work whilst the hydraulic load is there. Guessing there’s an issue with LS and have been told to look at brake valve LS. Any advice appreciated.

Sounds like you have a cracked rockshaft housing. You can check by removing the end plate and 3rd spool on the R/H side of the rockshaft housing. Will probably fund a hairline crack between high pressure and LS. If so there are modified parts available.

 

[Phil P]

Sounds like you have a cracked rockshaft housing. You can check by removing the end plate and 3rd spool on the R/H side of the rockshaft housing. Will probably fund a hairline crack between high pressure and LS. If so there are modified parts available.

Split rock shaft housing wouldn’t affect the steering and brakes as they get priority oil via the priority valve.

If I had to have a guess at the issue, I’d say the bronze bushes under the awash plate have disintegrated in the pump.
As I always say though the best place to start is some gauges and perhaps pull the suction screen and check for debris.

Tractor hours is also helpful.

 

[CHendrie96]

Split rock shaft housing wouldn’t affect the steering and brakes as they get priority oil via the priority valve.

If I had to have a guess at the issue, I’d say the bronze bushes under the awash plate have disintegrated in the pump.
As I always say though the best place to start is some gauges and perhaps pull the suction screen and check for debris.

Tractor hours is also helpful.

I’ve taken the screen out the bottom and changed the filters. She’s just shy of 10k hours

 

[Phil P]

I’ve taken the screen out the bottom and changed the filters. She’s just shy of 10k hours

Was there any debris in the screen?

 

[CHendrie96]

Was there any debris in the screen?

No was clean. Filters and gauze not long cleaned (500hrs)