Community Forums

LPD218 · 05-22-2014, 05:58 PM

I have read the many issues about the fill/don't fill the fuel filter on the single filter Freightliner chassis built during certain years when changing filters. Armed with this information I chose to install a new filter base and priming pump on my C7 Meridian keeping a single filter configuration. I took the list of needed parts I got from here (3126 engine) and went to Freightliner here in Kansas City.

I explained my current setup and what I wanted to do, they had the pump, but said the base was a CAT part and referred me to the CAT dealer down the road.

Freightliner printed out the CAT part #s and off I went.

The CAT parts guy was nice, but said the Freightliner supplied part#s I gave him were not for a C7. I then used the list I had from this site, same thing - not for the C7. The parts matched the CAT publication "Cat Fuel Water Separators and PrimeTime Priming Pumps" I had which listed kit (202-9871) for C7. I had the PDF file on my phone. Computer did not show this as a C7 according to the parts guy.

Another CAT parts guy at the desk had been listening and asked me why I wanted the parts and told me my chassis should have two filters and the one on the engine had a pump. I explained I only had one 2 micron filter with water separator in my setup and that was why I needed the parts.

The new CAT parts guy said I did not need a pump as all I had to do was install the dry filter and then turn the ignition key on and off seven times and this would cause the fuel pump in my fuel tank to purge all the air and the engine will start. He said I could hear the pump in the tank hum if I listened to the tank while someone turned the key. I haven't tried this as wife is not home.

I then went home empty handed and confused. I sent an email to Freightliner Help and asked if what the CAT guys said was true and received an response to "Ask CAT."

QUESTIONS:

Has anyone heard the seven on and off sequence to fill the fuel filter to run the pump?

Is there a pump in the tank powerful enough to purge the air?

Has anyone put a hand pump setup on a C7 single filter configuration keeping it single?

If so, what are the part numbers?

Thanks a bunch for all the wealth of information, but I am really confused.

dvmweb · 05-22-2014, 07:51 PM

An old diesel mechanic told me, if you can fill the fuel filter you are changing, fill it. Just did the annual on our coach. Filled both filters, WS and second, turned key on and off a few times and it fired right up.

Spizzer · 05-22-2014, 07:53 PM

Man, I can feel for you, as I went through a similar drill a while ago preparing to change my filters for the first time. I think I can answer some of your issues.

The switch on/off only works if you have an electric fuel pump on your system. From what I could gather, the cummins does, but not your C7. So that won't do you any good.

If your filter is not mounted on your engine, then it is not a Cat part, but added as part of the chassis build. The Cat primer will most likely not work. Have you looked at the top of the motor to see what is there where the second filter normally is? If that mounting block is there, you may be able to put the primer there.

Hopefully others will chime in, and hopefully others with the same single filter system.

Good luck, and I am interested to hear what you figure out.

Jeff

cbeierl · 05-22-2014, 08:10 PM

For what it's worth, here's my old posting Relocated Fuel Filter & Added Priming Pump. It contains pictures and part numbers for the priming pump, etc. Perhaps the easiest thing to do would be to go ahead and add the secondary (CAT) filter base and pump?

LPD218 · 05-22-2014, 09:02 PM

I guess another way to ask this is:

Can I use the 2 micron filter with water separator on a fuel base with the hand primer? So, all I want to do is switch out the current base with a new fuel base.

Chris,

Your post was one I used and presented to both Freightliner and CAT.

Jeff,

That was one of the questions I asked Freightliner Help. Do I have a fuel pump in the fuel tank?

Here is my engine:

cbeierl · 05-22-2014, 11:37 PM

Quote:

Originally Posted by LPD218

...
That was one of the questions I asked Freightliner Help. Do I have a fuel pump in the fuel tank?
...

As far as I know the answer is no, you do not.

Spizzer · 05-23-2014, 08:15 AM

Quote:

Originally Posted by LPD218

I guess another way to ask this is:

Can I use the 2 micron filter with water separator on a fuel base with the hand primer? So, all I want to do is switch out the current base with a new fuel base.

Chris,

Your post was one I used and presented to both Freightliner and CAT.

Jeff,

That was one of the questions I asked Freightliner Help. Do I have a fuel pump in the fuel tank?

Here is my engine:

Dave,

I am sure you do not have a pump in your tank. You can verify this by opening up your water drain on the filter and have somebody turn on the ignition to see if the flow rate changes. Also, there is no reason you cannot do what you want to do. If you get the CAT filter bracket and pump and mount it like Chris, then you are in business. Just be aware when you prime the filter, you are pumping the air out of it towards the engine, so you have to pump extra to get it past there. Chris might be able to tell you how much he primes.

jeff

LPD218 · 05-23-2014, 04:31 PM

I went back to CAT with the information I got here. Thanks!

The parts guy was a great help and had access to Freightliner information. He wasn't sure of the one elbow joint hose size and gave a guess. I got home and checked it and it was too big an opening for the tank side of the filter base.

I will get the correct elbow before I start my changeover. I will have to move the assembly up higher to clear the grill brace with the pump handle but I will use the horizontal bracket from the old filter base and turn it 90 degrees to accomplish this.

Once I get the right elbow, I will post a picture or two of the install.

I will save the parts and maybe tackle installing a secondary setup.

Thanks for all the help folks!

FIRE UP · 05-24-2014, 10:39 AM

Hey Dave,
Well, I don't know if you read my post/thread on the changing of the single/only fuel filter and trouble starting way back about a year or so ago but, it covered some of what you're up against. It still amazes me that there are folks that think there should be TWO fuel filters on every CAT engine ever made. Well, that's been proven about a zillion times that there ISN'T!!!!

And, contrary to some popular belief, not all motorhomes, especially diesel ones, HAVE FUEL PUMPS in the tank. If you find my thread on this issue, I made the "one time" mistake of not filling/priming the replacement filter. And, from that point on, it was a serious pain in the a$$ to re-start that CAT. There was no turning on and off of the ignition 'cause there's no fuel pump in the tank.

After calls to Freightliner, CAT and Bret Wolfe, it was determined that the only way I was ever to get that rig started again was to "PRESSURIZE" the tank with air. We (the wife and I) did just that. It took quite a bit of pressure and time, to get the fuel from the tank to the entry into the single fuel filter inlet, at the base.

Then, it still didn't start. So, I broke loose and removed, the line at the lift pump, at the base of the HEUI pump. I had her apply air once again to the tank filler spout. I finally got fuel to that point at the base of the lift pump. I then secured that line. I went in and, within about 6-8 seconds of cranking, she fired right up without a hiccup.

Well, it was determined that, during the fuel filter change, the fuel tank level, was lower than the height of the fuel filter. Well, when that's the case, you now "unlock" the hold that the fuel system has on the line, all the way from the lift pump, back to the tank. And, when that happens, you guessed it, all that fuel simply DRAINS back into the tank and you now have a 30' long air bubble.

So, I discussed this issue with many on here including Chris and, while the thought of installing a primer pump and or, a complete secondary filter and CAT priming pump had been considered, my resolution to the issue was considerably cheaper and, cured that problem forever.

The reason I did not fill the filter on that particular change was because I made the mistake of reading a CAT owners manual about changing the fuel filter(s). Briefly it told me to not fill the filter and the engine will do a "self priming" operation. Well, it seems even CAT doesn't know how and what, is in certain engines they make and or, on the Freightliner chassis vehicles.

My solution was simple. Two valves, one on the intake side of the single filter and one, on the output side. They are quarter turn valves. I can simply turn them and it shuts of the flow, in ANY DIRECTION, and I can now take my time in changing the fuel filter. But, I will forever, prime that filter with fresh fuel, even though I've got the valves on it. What I did was a good enough cure for me. If installing a primer pump works for you, great.
Scott

LPD218 · 05-25-2014, 08:35 AM

Scott,

Where did you find the valves? I haven't seen them before.

Nice setup!

FIRE UP · 05-25-2014, 05:38 PM

Quote:

Originally Posted by LPD218

Scott,

Where did you find the valves? I haven't seen them before.

Nice setup!

Dave,
You and I have PMd on this issue but, in case others are inquisitive about where they (the valves) came from, I got them from a local business that supplies hose, valves, fittings, rubber, hydraulic components, pumps, and a few zillion other goodie type items. Those set me back about, $14.00 ea.

After I regained consciousness, I did some research and found I could have purchased some equally effective valves, at places like Lowes, Home Depot, local ACE hardware and more places that were, in many cases, less than half that price.

The valve installation is just a simple method of isolating the filter from the rest of the system. As you can see and read, many folks think that all motor homes, and engines, are built the exact same. Well, as many of us have found out, that's surely not the case. Having fuel pump, INSIDE THE TANK, is a good thing, MOST OF THE TIME. That is, until it goes bad. Just how often that happens, I don't have a clue.

But, for those that don't have the fuel pump in the tank, you can turn the ignition on and off, ten zillion times and it won't do any good. So, as Bret Wolfe and I discussed when I developed my situation way back then, the partial answer is, keep the fuel tank fuel level, at or above the level of the fuel filter, when it comes time to change it. Now, that may be remedied by either filling the tank prior to the change or, simply elevating the front of the coach.

That is when I came up with the idea of the valves. With the installation of them, it doesn't matter what the fuel level is or, angle of the coach. I can change that filter, out on the road, with a low level of fuel, even parked on a down hill stretch, if I have to. Good luck.
Scott

LPD218 · 05-31-2014, 03:45 PM

I had all the parts ready to go and one last time of dry fitting everything before I tackle the install. The fuel filter base #151-5138 does not accept the fuel filters I have on hand for the OEM fuel base. I made an assumption that these bases use the same filters in motorhome applications. I even asked this question to the CAT parts guy.

From what I read, I can get 2 micron filters with water cup or without which isn't too much of an issue.

Can I get a short hose and run it from the OEM fuel base to the new base (mounted elsewhere) and then use the OEM fuel hose to the engine from the new fuel base and accomplish a two filter setup? I would use a 10 or 30 micron in the OEM fuel base with water separator and then a solid 2 micron in the new fuel base that has the pump.

Am I missing anything?

Thanks for the read?

RayJr · 06-02-2014, 05:52 PM

Guys I'll through my hat in, I have a 2003 Journey with the C7 cat. It dosn't have a lift pump and no primer pump on the motor. This motor has no injector pump like an old fasion diesel. It has a huei?? pump, that is a high pressure oil pump that fires the fuel injectors. Realy easy to check just look at your motor if you don't see 6 lines from an injector pump one line going to each cylinder you got the huei system. I've never had a problem changing the fuel filter with the plastic bowl on the bottom. Just unscrew the old one replace the plastic bowl on the new filter, fill the filter with fuel put it back and WALA your off. No I don't know how the thing is spelled. Like the Viet Nam chopper.

FIRE UP · 06-02-2014, 08:22 PM

Quote:

Originally Posted by RayJr

Guys I'll through my hat in, I have a 2003 Journey with the C7 cat. It dosn't have a lift pump and no primer pump on the motor. This motor has no injector pump like an old fasion diesel. It has a huei?? pump, that is a high pressure oil pump that fires the fuel injectors. Realy easy to check just look at your motor if you don't see 6 lines from an injector pump one line going to each cylinder you got the huei system. I've never had a problem changing the fuel filter with the plastic bowl on the bottom. Just unscrew the old one replace the plastic bowl on the new filter, fill the filter with fuel put it back and WALA your off. No I don't know how the thing is spelled. Like the Viet Nam chopper.

RayJr,
Well Sir, yes, you do have a "lift pump". It's inside the HUEI pump. That's how the fuel is transferred from the tank TO the HUEI pump. The HUEI does not have what it takes to get the fuel from the tank to the engine. The HUEI "boosts" pressure to the injectors by using engine oil to augment injector pressure. This is one reason why many guys, change oil a bit more frequently than the books or, specs call for.

And, yes, most guys will get lucky when changing the "single" fuel filter and not have what I (and others have had) what's called "Drain-back" of fuel, all the way back into the tank. As in my case, if the tank level is lower than the fuel inlet level at the single filter in the rear, and you loosen the fuel filter, the fuel has the propensity to, "drain back" into the tank due to GRAVITY!

But, if the tank level is up and or, at least the front end of the coach is at just a bit higher level than the rear, the probability of it draining back is cut way down. By pre-filling the filter, you cut down on the "starvation" of that "transfer or, lift pump" cavitating due to loss of prime. It can happen but, it's merely a "stumble" in the engine running and normally doesn't cause any cavitation issues.

Scott