Hydraulic Pressure

[Chubbsct4558]

I have a brand new Bobcat CT4558 and was wondering if anyone ever turns up their hydraulic pressure and what where the results.

 

[oldnslo]

Turning up pressure will provide more lift on a loader but depending on how much can also break axles, frames, pump housing, etc.

Have you checked to see what pressure is to see if currently at factory specs?

 

[SPYDERLK]

Are you talking general lift and implement hydraulics, or hst/motive hydraulics?

 

[Chubbsct4558]

Are you talking general lift and implement hydraulics, or hst/motive hydraulics?

If I’m trying to lift a semi frozen full bucket of snow it won’t lift it , also with my skid steers if I get stuck in the snow I can dig the bucket in and push myself backwards, the tractor won’t handle that. Thanks for your help.

 

[SPYDERLK]

If I’m trying to lift a semi frozen full bucket of snow it won’t lift it , also with my skid steers if I get stuck in the snow I can dig the bucket in and push myself backwards, the tractor won’t handle that. Thanks for your help.

Thats your general hyd system then. You should be able to find and make an adjustment pretty easy. The dealer, or someone with CT4558 ought to be able to help. Since its new, see if you can get the dealer to check it with you present. Your pressure may be on the low side of the spec range. Get it up on the high side measured with the fluid fully warmed.

 

[oldnslo]

If I’m trying to lift a semi frozen full bucket of snow it won’t lift it , also with my skid steers if I get stuck in the snow I can dig the bucket in and push myself backwards, the tractor won’t handle that. Thanks for your help.

Loaders on tractors rarely have the same force as skid steer since skid steer is designed around the loader capabilities while a tractor the loader is one of many possible attachments. Service manual should provide information on pressure setting and adjustment procedure. Could be a simple screw or may require some disassembly and shims.

 

[mark in portugal]

I increased the shims on my PRV to increase my tractor hydraulic pressure from 175 bar (2,500psi) to 225 bar (3250psi).
It's working very well.
But, I rarely go very high in actual use, at most for a few seconds to lift a loaded bucket.

I wouldn't touch it on a new machine though. Warranty would be very void.

 

[SPYDERLK]

I increased the shims on my PRV to increase my tractor hydraulic pressure from 175 bar (2,500psi) to 225 bar (3250psi).
It's working very well.
But, I rarely go very high in actual use, at most for a few seconds to lift a loaded bucket.

I wouldn't touch it on a new machine though. Warranty would be very void.

A big worry, if you go more than a few hundred psi more, is using too much of the spring travel getting the relief pressure to the setting you want. You need enough travel left for the poppet to move off seat far enough to still give adequate relief at full flow.