cat 308d sb

[cymro]

Hi, had an 09 cat 308d about 4 months ago and was down approx 1000psi on the hydraulic pump resulting in weak tracking and digging. Fitter came out changed relief valve on the valve block but no difference, then flow meter was put on and conclusion was pump needs replacing. New pump fitted and still down approx 1000psi. Machine was then taken away to the workshop to be sorted out but they couldn't, so after two months they swapped the machine for another same spec. Now this machine digs better but only marginally better at tracking i mean very weak - 2 speed only effective on completely flat or down hill. My question is would you be able to increase main pump pressure/flow on this machine? I know for a fact that no attempt was made to increase pressure on the first machine (maybe its not possible). Any info valued as i need to get it sorted whilst still under warranty.

Thanks C

 

[robin yates uk]

if it is under warranty you have nothing to worry about

 

[bigshow]

Outfit I work for has one, and we had the same problem. I told the mechanics it wasn't tracking for spit and they told me I was nutts. So I put it at the bottom of a 2:1 slope and told him to climb it, when he FINALLY got to the top a Cat tech was called in and he said it was "within caterpillar specs". I told him his "caterpillar specs" suck, well it still don't track for spit.

 

[cymro]

Problem is from what i can work out if the main pump output cant be increased then this is how these machines are. And if this is the case then its not for me even tho its a very handy sized machine for what i do . Thank god it has warranty

 

[cymro]

bigshow it doesn't look good then, will be doing the same tomorrow as the rep is coming out, if he comes out with `its within cat specs` he can track it back to his depot, its only about 75 miles lol

 

[bigshow]

I hate ours, it's the right size, just doesn't EVER seem to have enough power. It "replaced" our 307B and that 307 would eat the 308 alive.

 

[mikebramel]

High range is only for flat ground.
The problem is not the size of the pump or the pressure relief valve setting but the motor size when it is stroked in high range. It is too small and the pressures are too high

 

[bigshow]

Low range is your only option on steeper ground, it does nothing but grunt in "furry hopping thing mode". Don't even waste your time trying to track across a 2:1.....

 

[Per Eriksson]

Is it down 1000psi on all functions?
Was the new main relief valve adjusted when installed?

 

[cymro]

They said pressure was down 1000psi , i assume all functions - was very weak on tracks and would struggle to lift machine up with the blade but seemed to operate quick and smoothly. Yes the old and new relief valve was adjusted on the valve block to try and increase pressure with the old and new pump. Both pumps gave same psi. Nothing was adjusted on either of the hydraulic pumps. I think about 6 days was spent trying to increase the pressure at my yard with new relief valves and testing this and that by experienced fitter,

 

[Atlasrepair]

Hi, had an 09 cat 308d about 4 months ago and was down approx 1000psi on the hydraulic pump resulting in weak tracking and digging. Fitter came out changed relief valve on the valve block but no difference, then flow meter was put on and conclusion was pump needs replacing. New pump fitted and still down approx 1000psi. Machine was then taken away to the workshop to be sorted out but they couldn't, so after two months they swapped the machine for another same spec. Now this machine digs better but only marginally better at tracking i mean very weak - 2 speed only effective on completely flat or down hill. My question is would you be able to increase main pump pressure/flow on this machine? I know for a fact that no attempt was made to increase pressure on the first machine (maybe its not possible). Any info valued as i need to get it sorted whilst still under warranty.

Thanks C

I am having the same exact problems. Do you know what fixed it?

 

[lizrad999]

I have the same machine and it does the same thing. Very annoying.
Crawling up a hill is painful. It will kinda scoot in rabbit mode on flat ground, but I find I am always switching between bunny and turtle...more like snail...

 

[warpspeed]

Same here, love the machine otherwise....if anyone finds a solution, please please post.