Timberjack 480 hydraulics

Cruiser_79 · January 12, 2019, 11:40:44 AM

Hi all,
next week I go to a clients project, and they have a '98 Timberjack 480 with grapple. The operators told him that they have problems with a hydraulic pump that has been blowing out the seals for several times already... I don't know the details cause I haven't visited the site yet, but I think there is something else going wrong with the machine. They replaced the seal for at least 4 times already... Where can I find hydraulic schemes/plots of the hydraulic system? Maybe there is something going wrong with an overpressure relief valve or something like that.

mike_belben · January 12, 2019, 01:11:52 PM

Check to be sure that all return lines and case drains are routed direct to tank and that the pump had a dedicated suction line from the tank, and obviously that the tank vent works.

If you put pressure to the pump inlet side of most any pump, blown seals are the result. In a cheap gear pump [for instance] you can kinda build them to run backwards. the inlet port is usually a size bigger than the outlet port but otherwise they dont care. Except that the seals around the gears are shaped to prevent the pressure side from reaching the shaft seal from within. Ive fooled around with this, and also with supercharging of the inlet side and it always puked the shaft seal. So basically youre getting pressure behind the seal when it should probably be a vacuum condition or neutral.

Look around with that thought process in mind. You can easily have 500 psi burst coming down a return line when you open a spool on a heavy load.

Cruiser_79 · January 14, 2019, 02:18:36 AM

Okay thanks! When I get there I'll start checking the tank vent.
When return lines and the tank vent are okay, is there a chance that something is wrong with the pressure relief valve or the pump it self?
Anyway, I'll go there next week and find out what's wrong with the machine. It's standing somewhere in the middle of a bloody jungle so the pump won't be the only problem I guess :

mike_belben · January 15, 2019, 09:02:27 AM

Anything is possible with hydraulics. Sometimes ya got 3000psi on one side of a little dowel looking "valve" and a big spring on the other to do some endless variety of functions. any little flub makes that high pressure get into the wrong side and stuff gets wierd. Look at auto transmissions, theyre just a complicated hydraulic planetary that do stupid things all the time. Its always a "little" thing that makes for a major problem, upon diagnosis.

Good luck with it

Cruiser_79 · January 16, 2019, 09:10:38 PM

Went to the machine totday and seems that the seal and D-ring are blewn out. But I noticed that the pump isnt original. They cut a slice of the chassis to create enough space. So Im afraid that the pump gives too much pressure for the return lines etc. Does anyone know the specs of an original pump? Its about the pump bolted to the distribution of the engine, and its for the blade and steering.

Cruiser_79 · January 25, 2019, 03:22:43 AM

Cause we couldn't find anything about the placed pump, we made a temporarily seal of teflon. Was just for transport to a yard.
We checked the pressure behind the pump while steering and using the blade. Wasn't going beyond 190 bar, pressure relief valve should be 180 bar so that looks fine.
We think that the seal in the pump wasn't original but we couldn't find any specs of it. There is ETX on the pump housing, and a serial number. Does anyone here recognize the pump? And does someone know what pump is used in a Timberjack 480B original?

kiko · January 25, 2019, 09:43:03 PM

That is a Vickers V201 pump. The long number is the model code. Any Vickers distributor should be able to supply you with a shaft seal. The pump,IIRC ,must be disassembled to replace the shaft seal , while apart check any internal orings for damaged that may allow to much pressure to be applied to the shaft seal.

Cruiser_79 · March 21, 2019, 11:59:04 AM

Quote from: kiko on January 25, 2019, 09:43:03 PM
That is a Vickers V201 pump. The long number is the model code. Any Vickers distributor should be able to supply you with a shaft seal. The pump,IIRC ,must be disassembled to replace the shaft seal , while apart check any internal orings for damaged that may allow to much pressure to be applied to the shaft seal.

I contacted several distributors and no one could tell me what type of pump it is. They all tell me that it is probably too old or made under license by some manufacturer.
Does anyone have or know a Timberjack 480? This pump isn't original for this machine, I think there should be a gear pump in this place. If possible I want to replace this vane pump for an original or similar pump. What pump was placed by timberjack?
The pressure relieve valve is set at 180 bar, 2500 Psi. If I know the flow needed, I can find a new pump myself.

Oliver05262 · March 21, 2019, 08:54:23 PM

Baum Hydraulics has always had some very knowledgeable folks that can help identify unusual or unique components and can usually come up with a suitable replacement when necessary.
https://www.baumhydraulics.com/
Surplus Center is another good source for help and parts. https://www.surpluscenter.com/Hydraulics/