WorkHorse Fuel Filter Change

[JC2]

Will be changing the fuel filter tomorrow on our MH and was wondering if teflon tape is recommended or needed on the (3) connections?

[DriVer]

Quote:

Originally posted by JC2: Will be changing the fuel filter tomorrow on our MH and was wondering if Teflon tape is recommended or needed on the (3) connections?

No it isn't. The attachment points are flared and require no other sealing materials other than making the attachment point reasonably tight.

[BellaBo]

I have a question about the new connection. Is this a tank return line? If so,
1.Why is it needed?
2.What prevents the fuel from flowing to the tank which I assume would have less back pressure than the flow to the engine.
3. Relates to number 1, why did workhorse change the design from a straight fuel filter?
4. What happens if you just cap off the line and use the old style filter?

Sorry if these have been asked and answered before. Could find a thread.
Thanks,

[DriVer]

Quote:

Originally posted by Streamerman: 1.Why is it needed?

Supports the returnless fuel system. The basic concept is to improve the evaporative emissions of the fuel system and it eliminates fuel being forced at times 25 or more feet forward to the engine and returned to the tank.

Quote:

2.What prevents the fuel from flowing to the tank which I assume would have less back pressure than the flow to the engine.

The rail downstream becomes pressurized and the excess fuel returns to the tank through the vertical pipe. There's plenty of pressure to do both. I believe something like 55 psi.

Quote:

3. Relates to number 1, why did workhorse change the design from a straight fuel filter?

Actually GM called for the change. It improves the total emission control package.

Quote:

4. What happens if you just cap off the line and use the old style filter?

You will not provide a return path for the pressurized fuel charging the rail. The fuel pump is also cooled by the return stream of fuel to some degree I understand so that would be compromised.

[knebrdr]

What is the recommended replacement interval as per Workhorse? I see posts here all the time about "I am replacing my ff." or "You need to replace your ff!". I spent 35 years in the auto repair business and have not seen this kind of fuel filter paranoia since the early 70's. Is gas in the rest of the country sold only at old gas stations with rusty tanks?
Randy

[oemtech]

DriVer forgot one other important reason for the returneles system.

Cost.... they save a few cents/dollars.

But, also creates a problem. A proprietary fuel filter and a single source supplier.

I spent a few years turning wrenches in the tune up business. You would be surprised the number of times we changed the fuel filter and the customer commented how great the car ran the next time they came in for service.

As I have said before... An RV is a different breed of cat. It is not used for months and then used a bunch. You get 50 to 60 gals a gas at any one time and it may be in 3 or 4 states.

Lastly, you need to cut a few apart just to see what is going on.

[BellaBo]

Thanks for the explanation of the filter changes.

If G.M. called for the change and it is an emissions improvement, I wonder why all G.M. vehicles don't have the same filter system? Therefore, readily available filters.

It's a moot point but maybe, Oemey hit the nail on the head. Cost!

[sal avitabile]

I think a reason for the return line on the fuel filter is to stop vapor lock caused by excess heat in fuel systems

[JC2]

Got the fuel filter done today and it was a simple 15-20 minute job. It was rather spooky though sitting under about 20000lbs of metal. No worry though as the wifey was standing by to lift if necessary. Now for the plug and wires just haven't decided whether to tackle it from the top or bottom.

["007"]

JC2 just turn your wheels outward which ever side you will work on plenty of room its a piece of cake.

[max49]

Quote:

Originally posted by "007": JC2 just turn your wheels outward which ever side you will work on plenty of room its a piece of cake.

And like Driver said before, Bring the box of bandaids into wheel well with you, saves a lot of time, over going back and forth to get them.

[knebrdr]

The main reason for the "returnless" fuel system, fuel return at or near the filter, was to keep the fuel cooler by not running all of the fuel through the fuel rail on the engine, just the fuel required by the increase or decrease in injector pulse width (a dead end system). Cooler fuel means better performance, less evaporative emissions from the fuel tank, and hopefully longer fuel pump life (fuel pump failures on through the rail systems were quite high because of elevated returned fuel temperatures).
Driver, what is Workhorse's recommended fuel filter interval? The reason they are probably hard to find at times is they did not produce alot of them based on the recommended replacement interval. In Ca. they increased the fuel filter replacement interval on all passenger vehicles to 100,000 miles in 1995 or 96 and shortly after increased it to this mileage at the federal level.
Randy

[edgray]

Quote:

What is the recommended replacement interval as per Workhorse? I see posts here all the time about "I am replacing my ff." or "You need to replace your ff!". I spent 35 years in the auto repair business and have not seen this kind of fuel filter paranoia since the early 70's........

knebrdr: to answer your question, quoting from the workhorse gas chassis guide, ""The gasoline fuel filter has no periodic change interval. It can last for years or hours if contaminated fuel is encountered. The symptoms of a plugged gasoline filter are gradual loss of power until the engine dies. The engine will often restart and run with reduced power.""

I cannot understand all the concern, either, as mine has "filtered" approx. 6,000 gals of fuel and my engine certainly has not lost power yet. ED

["007"]

I just read that same paragraph yesterday, way to go ED.
Of course after I bought a NEPA GOLD will just put in my parts bin for now have changed them before on the road.