CAT C7 fuel pump, bad after 40,000 miles

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RobertR

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Sep 19, 2011
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Win 2004 Journey, CAT C7 engine with 40,000 miles on it. 

Started missing, fuel pressure is low, Freightliner says fuel pump, injector pump and injectors need replacing.  Cost ~ $8000.00

I am wondering what would make all that go bad in just 40,000 miles?  Don't want to repeat this. 

Primary fuel filter had black jelly substance in it.  Algae, bio-fuel, or rubber from fuel lines?

Would stopped up fuel filter make pump go bad?

Any one had problems with algae in the fuel?
 
That many miles on a nearly 9 year old coach is not very much.  Most likely it sat for long periods with contaminated fuel in the tank.  Could be algae, or just water in the fuel that corroded the insides of the fuel system.  The best thing you can do for a diesel is run it often, and hard.  They like working and under load is best.  Long term sitting with short runs or minimal idling will kill it quick. 

If you are going to replace all that stuff, make a commitment to take it out regularly and run it.  There are stabilizers for fuel in vehicles that will be sitting for a period of time, but driving it is best. Let us know what they find when they tear it down and do the replacements. 
 
Wonder why the filter(s) didn't catch any of that gunk?
 
The black stuff is fuel algae. Biologically it isn't an algae, but that's what it is called in the diesel business. It comes from sitting around a lot with moisture in the fuel tank, either pumped in with (bad) fuel or accumulated from condensation in the tank. Most likely condensation, based on your description.

Given that yours is a 2004, it may have only one filter. Both Cat & Cummins allowed that in 2003-2004, but then re-learned that two filters is a better scheme. The primary filter (which is combined with a water separator) is after the lift pump, so it is likely the lift pump is full of the crap too. It could probably be rebuilt,  perhaps even just flushed out, but it seems the usual procedure is to simply replace it (it's not their money being spent!). I would also be concerned about the tank itself - it may be necessary to have the fuel "polished", meaning it is pumped out through a filter to remove crud, then pumped back in.

As for the injector pump and injectors, it may be that some gunk got through the filter. They are never quite 100% efficient, so some contamination may have gotten by. I see no risk in just doing the tank cleansing and lift pump first and see how it runs. You can always do the injector pump and injectors later. They are the bulk of the cost.
 
It has 2 filters, one behind the radiator and another by the fuel pump. 

I have had the unit for ~ 18 months and have put ~ 20,000 miles on it.  It doesn't sit much. 

Have decided that i need to treat with algae killer about once a month. 

It must be that some of it got by the filters and clogged up the injector pump and injectors, but why would that make the fuel pump go out? 

Anything wrong with adding another filter?
 
The injector pump and injectors are extreme high pressure and very sensitive to contamination. Repair shops don't rebuild them - not even sure if the factory does. The lift pump, however, is just a regular pump and I would think that a competent person could clean or rebuild one easily enough. Chassis repair shops don't seem to do that, though, probably because it is labor intensive and still might not work. But if you can do it yourself, the labor factor is much different.
 
Gary RV Roamer said:
I would also be concerned about the tank itself - it may be necessary to have the fuel "polished", meaning it is pumped out through a filter to remove crud, then pumped back in.

As for the injector pump and injectors, it may be that some gunk got through the filter. They are never quite 100% efficient, so some contamination may have gotten by. I see no risk in just doing the tank cleansing and lift pump first and see how it runs. You can always do the injector pump and injectors later. They are the bulk of the cost.

Does it make sense to do these maintenance things whenever buying a used diesel?  If it's not outrageously expensive, it seems like it would be a worthwhile investment.
 
It sounds like for $8000.00 they would be changing injection pump, lift pump, fuel filters , dropping the tank, flushing the tank and all the lines . It doesn't sound like miracles will be around the next corner. Cat build solid stuff but doesn,t come cheap. You could talk to the service manager about rebuilt as he might be quoting new. Also Antrim Diesel in Pennsylvania would be worth a call. They sell FASS (fuel air separation system filters and lift pumps . I found them good to deal with. You might find you could buy the parts from them and pay the labour rate at a good diesel shop and do better for less money. Stnadyne I understand only approve an additive which is a demmulsifier
which HOWES happens to be. However sounds  like your damage has progressed beyond that. An earlier thread spoke about bio. I filled at a TA and they use up to 20% bio which GM claim to be acceptable  to their new vehicles a couple hundred miles from St Petes. Next day when I started truck it had a bit of an unusal hunt at idle until warmed up. After filling at a Chevron back to normal. Anyway good luck keep us informed.
 
Well were out of the shop a month and $9000.00 later.  Mechanic told me that CAT has had problems with that fuel pump.  The springs break, flow on down to the injectors and stop them up. 

I asked if there was a recall on the pump?  Yes but that was several years ago and no longer good.  So I said if one was lucky enough to get the word on time CAT would have put a new pump on for free, but since I didn't get the word I now have to pay for it?  Yep, he said that's right.

Don't sound right to me.  A recall should not expire.  ????

Service contract with Xtra ride paid for $1700 = the fuel pump
They would not pay for injectors which were $3500 just for parts. 

I don't know if I got a new injector pump or not.  There is something on there called INJ GRP Core $884.00 

  I feel like I got the shaft.

 

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