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rv dreamer · 02-24-2014, 06:59 PM

We own a 2000 National Tradewinds RV and have had it in storage during the past 4 months. It has been extremely cold here in Atlanta this winter and when we went to start the engine yesterday, it wouldn't crank over. We opened the fuel cockpit on the filter to let the water out and no fuel came out. When cranking the engine again, we went back to check fuel filter, opened the cockpit, there was a gurgling air bubble noise. Camping World says we lost our prime. Question...is there a manual fuel pump on the CAT 300HP engine or is it an electric pump? Where is the pump located and how would you prime it? Unfortunately, we didn't use fuel conditioner and Camping World says the fuel may have algae. Is that possible and would that cause engine not to start? Can I still use the fuel in the tank? We appreciate any answers you can give us.

Thanks in advance for your help,
(Frustrated) RV Dreamer

**TonyDi** · 02-24-2014, 07:43 PM

It is not likely that you have algae in the winter. That would not make your fuel not run out of the fiilter. You probably lost prime.

Rook · 02-25-2014, 06:48 AM

On my 3126B CAT 300hp there is a small hand pump sitting on top of the engine, front, near the little fuel filter, that is used to purge the fuel line of air when the little filter (or any fuel filter) is replaced. I've never used it so I cannot tell you how. It looks pretty simple (viewing from top under the bed). Service people use it all the time. Rook

RayJr · 02-25-2014, 07:22 AM

The C7 Cat you have more then likley has no ele fuel pump it relys on a lift pump in the hue pump. Not like normal diesel motors the C7 has no injection pump it works on a high preasuer oil pump to fire the injectors. Also no manuel pump to regain prim. Easy to tell if you have this system just look at the engin for a normal injection system with 6 lines on it if not there you have a hue pump. Now Camping world has no idea what there talking about. Now when you say " wouldn't crank over" ya mean the thing wouldn't turn over or it was and wouldn't start. My C7 had 2 issues the first one was looping, sounded like it was burping. No codes showed it would start up but burped at idel and was smooth at high idel. That turned out to be the hue pump. Second time the thing started up then died because someone opened the fuel filter pedcock and it lost prime. No way could I get it started, finley called my cat guy and he said he would get it going. Well he didn't and it turned out to be the lift pump in the hue pump. Ya should replace the filter then try it if it dosn't start get a real diesel guy because your just going to go nuts. If there is a primer pump on the injection pump then its a whole different bird. Just change the filter and crack a few injector lines and pump till ya get fuel up to the injectors them it should fire right up. I hope I didn' confuse ya. 2 different fuel supply systems on a diesel.

wb7auk · 02-25-2014, 07:39 AM

You have a 3126B engine C7's did not appear until 2004.
As Rook stated you should have a prime pump at the engine on top of the fuel filter
and as I recall on top of that filter is a bleed screw that you loosen so you can pump
the air out of the system.
It will take several pumps to clear the system.

Vegasdan · 02-25-2014, 07:03 PM

You definitely have the 3126B and in 2000 I believe they still had 2 filters and the priming pump. My 2001 has one filter and the engine is supposed to self prime when cranking, although I've never had to try this.

chboone · 02-25-2014, 11:35 PM

Depending on your low temperatures the fuel could have gelled. If you've never used a priming pump, unscrew it (counter clockwise) and start pumping, you can open the bleed screw if you want but normally isn't necessary. In a while you should feel a difference in the feel of the pump. Keep pumping until till the pumping gets firm. Screw the pump back in, try to start engine. If you were successful the engine will run, but rough at first. Hold the RPM's at around 1000 - 1200 for several minutes. The easiest way we found to prime CAT 3412 12 cylinder engines was to crank the engine and pump the primer as fast as we could till the engine started.

Chuck

rv dreamer · 03-16-2014, 10:57 AM

Thanks, Everyone, for your advice! I was successful in getting the engine primed and it worked like a champ just like you said.

Couldn't have done it without your help,
RV Dreamer