35D lost power on all functions (travel, digging, lifting)

Hi all, serial no 265120, 6700 hours. It started being slower than before, it will barely lift the machine now and much slower on both tracks. I changed hydraulic filters and oil and same problem. There is some noise coming from behind under the cab but I am not sure where it is from. The swing motor speed seems fine. I am wondering where I should start investigating / testing ? Any suggestions will be greatly appreciated. Thank you Richard

I'd start with a system pressure test. I have no experiance with this machine, but I had the same symptoms with my Hitachi 120 several years ago.I ended up taking the main relief valve out of it, taking it apart and cleaning it up entirly, put it back in and away she went. I never did see anything in the relief valve, but I'm sure that is what it was. I did this several times over about a one year period and finally drained and pulled the hydraulic tank, pressurewshed the heck out of it, dryed it real good, filled it up and never looked back. Good luck

Could someone share with me where the main relief valve is ? I don't have the technical manual for this machine.

Deere, right? Please post the entire serial number. That machine has 3 reliefs. One for each pump. Pilot pressure needs to be checked as well as the system reliefs. If this is something you are looking to tackle yourself, you will really need to acquire the Operation and Test manual TM2263.

mg2361 said: Deere, right? Please post the entire serial number. That machine has 3 reliefs. One for each pump. Pilot pressure needs to be checked as well as the system reliefs. If this is something you are looking to tackle yourself, you will really need to acquire the Operation and Test manual TM2263. View attachment 351436 Click to expand... Thank you, yes, John Deere, same machine I had a thumb problem with.

I downloaded the manual from the Deere site. Tilted the cab, the vibrating sound is coming from the pump when lifting the boom but it is tracking much slower both speeds and both tracks than before.

Before I change the hydraulic pump, the 2 large hoses from the pump(1 and 2) are connected to a block with a solenoid below the pump along with other hoses. Then, 2 large hoses go to the valves manifold, Does anyone know what that block is for ? I can't find that in the manual. I know the seller had something installed for a brush cutter along with a switch in the cab and setting to oneway flow makes the brush work. I know that added switch has a problem because when turned off, the thumb no longer works. Anyway I am wondering if my lost of power could be the intermediate block the pump 1 and 2 goes to before going to the manifold.

That block mostly likely to be an auxiliary diverter valve for the cutter/thumb. Since your switch is acting up, the solenoid or spool inside is probably stuck halfway, dumping your pump pressure straight back to the tank. That explains the low power and pump noise. Before buying a pump, try to bypass that block. Hook the pump hoses directly to the main manifold. If power comes back, that block is your issue.

I hooked the 2 pump hoses on the main manifold and same problem . I capped and plugged all the other hoses from that block except the one that goes to the tank. I also have the switch unplugged, I don't know if that would cause a problem because the switch has 3 pins. The thumb is not moving but was when the switch was to the high position. That's probably another problem.

I got a new pump from a reseller but it does not have the Port for the pilot hose when the A/C is turned on. If I understand correctly, that port is used to change the swash plate angle of the hydraulic pump. They told me to use the port in the picture instead. When I do that and turn on the A/C I loose all hydraulic functions. Should that work ?

@Richard V , The hydraulic pump reseller is blowing smoke. The 35D (sn# 265000 and up) A/C equipped machines require hydraulic pump model PVD-1B-32 CP , Deere part # 4699383 .

Diesel Dave said: @Richard V , The hydraulic pump reseller is blowing smoke. The 35D (sn# 265000 and up) A/C equipped machines require hydraulic pump model PVD-1B-32 CP , Deere part # 4699383 . Click to expand... That is what mine is on the left. On the right is the one they sent me.

In your above pic , It is obvious the A/C control signal port is missing on the pump from the reseller. The pic is too blurry to make out the two pump model numbers on the tags. If the reseller pump model is not PVD-1B-32 CP , it needs to be returned . Is the reseller not able to provide the correct pump ?

Diesel Dave said: In your above pic , Its obvious the A/C control signal port is missing on the pump from the reseller. Is the reseller not able to provide the correct pump ? Regardless, the pump needs to be returned to the reseller. Click to expand... That is what I told them when I got their pump, they said to plug the hose in the other port from the previous picture. I don't think they know what they are talking about. I am going to undo and return the pump. Thanks for your input.