David Brown

[simonm]

What pressure should the hydraulic pump be putting out on a DB 990 Implemtic? i have heard between 2000-3000 psi is ok, i have recently purchased the tractor and have just tested the pressure at 1700 psi. however i have just started servicing the tractor as by the looks of things it has not been done for a very very long time! could changing the filter/ cleaning the system out increase the pump pressure? or is this as good as it gets? what pressure would a new hydraulic pump work at? or if necessary can the current pump be uprated?

[treequip]

What pressure should the hydraulic pump be putting out on a DB 990 Implemtic? i have heard between 2000-3000 psi is ok, i have recently purchased the tractor and have just tested the pressure at 1700 psi. however i have just started servicing the tractor as by the looks of things it has not been done for a very very long time! could changing the filter/ cleaning the system out increase the pump pressure? or is this as good as it gets? what pressure would a new hydraulic pump work at? or if necessary can the current pump be uprated?

 

Hi Simon

 

When it rolled out of Meltham the pump would have making 2000psi

 

Down to 1700 isn't good but its better than some

 

Cleaner oil isn't going to make the pump produce any more pressure but it will last longer not pumping a decades worth of crud around the system.

 

You can swap the pump out for a new one but an upgrade can bring you more problems.

 

The system is set up around the 2000psi, you can give it more but a lot of the system is old school on rubber "O" rings and they often blow out with an upgrade.

 

You can also can also blow the rings out if you replace a tired pump with a new one but that's something you have to live with. Replace the seals and its all good again.

[simonm]

If i replace it with a new pump 1 that is the same as what on only newer would this take it up to the 2000 psi needed? as its in bits now anyway i mite as well look at my options, keeping it how it is isn't of any use to me!

[treequip]

A new pump will bring it back to the 200psi

 

Have you got the old pump off?

[cornish wood burner]

As treequip says 1700 is not so bad as some. Was that at tick over or with some revs. If fairly constant might be worth checking the relief valve. Presumably you have cleaned the pickup. Been out of that game for 20 years but I have a vague recollection of a split copper pipe on one tractor. With the lack of servicing sounds bad for the pump though.

[simonm]

A new pump will bring it back to the 200psi

 

Have you got the old pump off?

 

Not yet, i have just serviced the engine and have drained the transmission fluid. think i mite have a look at a new pump because the 1700 its knocking out isn't enough for the little splitter. I haven't looked into it much but from what i can gather the pump is located under the pto? have you messed about with 1 of these before?

[treequip]

Not yet, i have just serviced the engine and have drained the transmission fluid. think i mite have a look at a new pump because the 1700 its knocking out isn't enough for the little splitter. I haven't looked into it much but from what i can gather the pump is located under the pto? have you messed about with 1 of these before?

 

More than I care to remember, they were made a few miles from here and are pretty common in these parts

 

The pump is inside the PTO housing

[simonm]

Is it difficult to get at or is it just a case of removing the housing around the PTO?

[treequip]

Is it difficult to get at or is it just a case of removing the housing around the PTO?

 

Take the nuts off around the PTO housing then lift the housing away, back and slightly upwards.

 

Reverse to re fit, mind the pick up pipe

[simonm]

Take the nuts off around the PTO housing then lift the housing away, back and slightly upwards.

 

Reverse to re fit, mind the pick up pipe

 

And the the job lot comes off the rear end? I have been told to renovate the shims from a relief valve above the pump. do you know anything about this?