Cat 257B 2 down on power

[Seanndiane]

Thanks for your help. The silt is accumulating in the small filter between the tank and the engine mounted transfer pump. I'm considering getting a hand pump and syphoning the last qtr tank out through the fuel pickup to try and speed the cleaning process. Those small filters are $13 each, so if I can spend an hour trying to suck the grit out, it might save me a few filter changes. (It was owned by a tree service with 4 loaders so they probably pumped fuel out of a large tank and didn't bother with a screened funnel like I use)

 

[Nige]

According to the Service Manual there is a drain plug on the tank for water and sediment. It is located under the machine at the left rear corner. See illustration. Make sure you partially unscrew the cap to relieve any pressure that might be in the tank before removing the plug. The manual also suggests that the draining process be done when the tank is almost empty.

 

[Seanndiane]

You are awesome....thanks!

According to the Service Manual there is a drain plug on the tank for water and sediment. It is located under the machine at the left rear corner. See illustration. Make sure you partially unscrew the cap to relieve any pressure that might be in the tank before removing the plug. The manual also suggests that the draining process be done when the tank is almost empty.

View attachment 118364

 

[Daviscorey]

You can remove and inspect the transfer pump on the engine before replacement there a small rubber diaphragm inside that does the pumping if it's ripped its won't work correctly. There's like 6 screws on top of it and a screen inside there as we'll


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[crankyster_01]

You can remove and inspect the transfer pump on the engine before replacement there a small rubber diaphragm inside that does the pumping if it's ripped its won't work correctly. There's like 6 screws on top of it and a screen inside there as we'll


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I have seen the screen inside the pump be covered in crap and cause issues like your having, good place to look.

 

[jbarry]

An interesting thread (subscribing). I have the very same machine, same year too. No fuel problems yet, thankfully.

 

[Nige]

To prevent this type of issue is quite easy. Make sure the water and sediment is drained from the filter bowl on a regular basis, how often really depends on how many hours a week put on the machine. Also maybe once or twice a year drain the crap out of the fuel tank.

 

[D3DaveC]

Wondering if it was the silt causing the problem?

 

[calint]

I have the same problem with my 257b. When it gets half a tank it sputters I’ve blew all the lines out changed fuel filters pulled the pick out thinking it might be broken. Still doing it. I’m wondering if it could be the transfer pump.

 

[thepumpguysc]

Welcome to the forum Calint..
Its very possible the lift pump is getting some age & should be checked.. U can take it apart & have a look & at the very least, clean the screen..
U say u blew the lines out.. UNLESS ur taking them off & blowing them out.. All your doing is blowing that "stuff" back into the fuel tank..
How about running it low & using the drain screw on the tank, get u a clean white or yellow bucket & SEE whats in there..
Good luck & let us know how u made out..

 

[kshansen]

Never had anything to with a 257, but every machine we had at the quarry that had any kind of drain that would allow you to control the fuel coming out I would crack that open at every oil change and let it drain while I did the oil change. Very seldom got more than a couple drips of water but if not done for a year those few drips would have added up to a big mess in tank and filters!

Same thing needs to be done on what ever tank you fill the machine from!

 

[Kxnate]

Had the same problem with my JD CT322 when I got it, would run for about 2 hrs than just fall on its face. Kept plugging the in line fuel filter at the tank. Found there was a bunch of dirt in the tank. Like you said, those filters get expensive. I bought 2 of the glass fuel filters that you can take apart and blow out the screens, whenever it would act up I would swap the filter out and clean up the plugged one so it would be ready to go next time it acted up again. I think I pretty much have all the dirt from the previous owner run out of it now as I haven't had any plugging problems in quiet some time, but it took several tank fulls of good clean fuel and numerous filter changes to run it out.

 

[Kim Sparling]

Hi guys. I know this is an old thread, but I read it with interest as I have had similar issues with my Cat 257B. Mine is a bit older (2005) but low hours. (Serial number SLK05345) The interesting thing is that there is no filter on the suction of the transfer pump (that's what Cat calls the pump that feeds the fuel rail pump). The filter is after the transfer pump. I have drained the tank, replaced the transfer/lift pump, and changed the water separator and fuel filter multiple times. I've also cleaned the screen in the transfer pump a number of times. I still get issues occasionally, and always on a lower tank level. I wonder if the transfer pump has enough suction head to pull fuel through a primary filter, if I install one. There are many after-market filter and filter housings available. Any thoughts on this? Also, I'm beginning to wonder if there is wear on the cam lobe that drives the mechanical transfer pump. There is nothing wrong with the pump or the diaphragm inside..

 

[Nige]

if the problems generally only rear their head when the tank level is low have you considered the possibility of an air leak in the fuel suction line inside the tank that only happens when the fuel level gets low enough to expose the dodgy section of the suction tube..?

 

[Kim Sparling]

Hi Nige. Thanks for the reply. I guess that's a possibility. Getting the unit out of the tank to check it will be a nightmare, but it seems I have exhausted most other possibilities.

 

[Nige]

Try draining water and sediment out of the tank and see if that helps. See post #22 above.
Do you have an Operation & Maintenance Manual for it.?

 

[Kim Sparling]

I drained the tank last night and I'm on my way to get some fuel filters to start over. Hope it works.
Did you consider my question regarding a filter prior to the lift pump? Is there a screen on the fuel pick up?
Yes i have an operations and maintenance manual for it.

 

[Nige]

The jury's out as far as I'm concerned, although I think I would try to get it running right before introducing another unknown into the system.
Heymccall, a member here, swears by an inline filter in the system. A link to it is below.
https://www.heavyequipmentforums.co...ss-of-power-moving-forward.78699/#post-832995

 

[Kim Sparling]

Agreed. The lines to the tank are clear. The drained fuel was less than clean. I'll replace all the existing filters and new fuel and try again.
I'm hoping the sediment has more or less drained out with the fuel. It would be helpful if the tank wasn't flat bottomed..
Ill be buying a few filters and change them again after running the machine a few hours or at least a tank of fuel..
I'll keep you posted.

 

[Nige]

Suggest that you should try to drain the tank of water and sediment on a regular basis until you are sure there is nothing left to come out. The cr@p ought to slop around the bottom of the tank as the machine moves and eventually work its way to the drain.
At that point your new filters have half a chance of living.