Cat 257B 2 down on power

[Kim Sparling]

Hi Nige.
That's the plan for now. I drained the tank and replaced the main water separator filter, as well as cleaned the screen in the lift/transfer pump. I also installed a transparent in-line filter on the line from the tank to the transfer/lift pump. I used a small electric fuel pump to prime and bleed the system and to fill the filter(s). I then removed the electric pump and bled the remaining air from the system in a normal fashion. I worked the machine for a few hours. No issues yet and the suction in-line filter still appears to be clean.. I assume the sediment will make its' way to the suction tube eventually and be caught in the in-line filter.
So far, so good.

 

[heymccall]

Take the filter head apart. Ensure there is no debris in the head inlet, or the top of the filter housing.
Pinch off your fuel line from tank and unscrew top plastic ring from filter head. Lift off primer. Lift out plastic funnel type insert. Clean out everything.
If crap is found, use an inline screen between tank and filter (like in the before referenced thread.


Your symptoms indicate a blockage/ restriction in the filter head. Unfortunately, it is very common.

 

[Kim Sparling]

Thanks heymccall.. That's good advice. Anything not caught in the left/transfer pump could accumulate in the filter head. I have installed the inline filter in the line from the tank to the lift pump. Initially I was concerned that the lift pump would not have enough suction head to pull through an inline filter, but it seems to be working fine. If it becomes partially plugged I suspect there could be issues with fuel starvation. So far, 4 days of work and no issues.

 

[Bryant Loomis]

Hello all.

I am having a problem priming my fuel system. I am not getting fuel into the fuel-water separator, therefore I’m not able to prime the fuel rail. Any suggestions?

I have a 2005 257B. SLK00532

 

[Nige]

https://www.heavyequipmentforums.com/threads/cat-226-fuel-problem.78929/#post-873504

 

[heymccall]

Hello all.

I am having a problem priming my fuel system. I am not getting fuel into the fuel-water separator, therefore I’m not able to prime the fuel rail. Any suggestions?

I have a 2005 257B. SLK00532

It was built 02/09/04.
This hand primer is removable from the filter head.
Once removed (by spinning off the plastic collar), you can inspect the diaphragm for distortion.
Also, it is not uncommon for debris to accumulate and block the inlet to the separator housing. So, when you are inspecting the priming pump, it would be the perfect time to ensure that the inlet isn't plugged from the inlet elbow to the outer passage here.

The thread listed above by Nige kinda covers it, but I thought I would clarify.

 

[Nige]

Seems like there's been a run of the same issue recently.
I think this is the 3rd in a week if memory serves.

 

[Bryant Loomis]

Thank you for the photos and clarification. Hopefully this will get it to prime.

 

[heymccall]

Arrow points to diaphragm that distorts.


And, did this happen after changing the filter?
It is not uncommon for the O-ring to be omitted or lost when changing the element and reinstalling the water bowl. Arrow points to that here.

If you lost or forgot that, it will never prime.

 

[muddog1975]

If it has a mechanical pump, there is a screen that never gets cleaned inside it. Pump is located on the block and it has a bolt on top. Loosen bolt and remove cap, be careful it has a small o-ring on the inside of the cap on the bolt. Take a pair of needle noise pliers and remove the screen. They are usually stopped up with debris. Good luck.

 

[John-Car257B]

Hi everyone, I have a 2007 cat 257B perk 3024c unit loses power during WOT and moving forward it low rpms and when I let go of joysticks it seems to take 15s and rev’s back up. Also to add it seems fine when I have a full tank. What I’ve done- changed fuel/water separator, changed hoses, and also cleaned screen in manual fuel pump. Seems to be a fuel problem but also had milk in hydraulics so have changed that now as well.SN:SLK03916

 

[thepumpguysc]

It’s a supply and demand situation..
So it’s probably a partially clogged filter/screen somewhere..
When u DEMAND MORE FUEL, it’s not available..
Reread the past posts and go from there..

 

[muddog1975]

You said it runs good with a full tank.... check you pick up tube or hose in the tank....possible cracked above fuel level when not full.
Milky hydraulic oil, try to find out where it's getting in at. Long term that not good for the hydraulic system. Hope you get it fixed soon. Good luck

 

[John-Car257B]

You said it runs good with a full tank.... check you pick up tube or hose in the tank....possible cracked above fuel level when not full.
Milky hydraulic oil, try to find out where it's getting in at. Long term that not good for the hydraulic system. Hope you get it fixed soon. Good luck

So after further test I am mistaken I’m down to a quarter tank and it runs great at like a happy medium throttle but full throttle out of nowhere it bogs down and when you stop touching joysticks it picks back up within 30sec and then works like a dream. Seems to happen frequently when at full throttle. It’s like something is telling it to shut fuel down for a min and then when machine is standing still it revs back up. It’s strange- also to add I placed GoPro in compartment to watch fuel filter and it’s not losing fuel in filter

 

[heymccall]

So after further test I am mistaken I’m down to a quarter tank and it runs great at like a happy medium throttle but full throttle out of nowhere it bogs down and when you stop touching joysticks it picks back up within 30sec and then works like a dream. Seems to happen frequently when at full throttle. It’s like something is telling it to shut fuel down for a min and then when machine is standing still it revs back up. It’s strange- also to add I placed GoPro in compartment to watch fuel filter and it’s not losing fuel in filter

It won't "lose" fuel, just have reduced flow, which you cannot see.

 

[muddog1975]

So after further test I am mistaken I’m down to a quarter tank and it runs great at like a happy medium throttle but full throttle out of nowhere it bogs down and when you stop touching joysticks it picks back up within 30sec and then works like a dream. Seems to happen frequently when at full throttle. It’s like something is telling it to shut fuel down for a min and then when machine is standing still it revs back up. It’s strange- also to add I placed GoPro in compartment to watch fuel filter and it’s not losing fuel in filter

It sounds like trash in the tank....I had a excavator do the same thing....it was a piece of plastic...like the kind around new filter.....it would float around in the tank and would get suck up by the pickup screen....and when it would be idled down or shut off it would float away from the pick up screen. Check your tank for debris of trash. One question, when you remove the fuel cap dose it hiss at you? Check your fuel cap, make sure its venting. It's hard to troubleshoot with out being hands on...lol...good luck

 

[John-Car257B]

I’ve dumped the tank already and found lots of rust and black algae so when I filled back up I added cleaner for the algae. I’ll probably end up taking it to cat and seeing what it is. I’m over my head on this thing already- bought for 12k and have close to 30k in it now. New rollers tracks rebuilt motor hyd ecm- the guy before me bypassed the 2nd ecm so sooner or later I’ll be into a new one of them

 

[thepumpguysc]

If u put a “biocide” in the tank w new fuel.. its made to kill the algae..(obviously)
NOW u got dead algae in the fuel.
And guess where it ends up.??
in the lines and filters..
U always have to keep changing filters till it’s gone..