1998 Foretravel U295 - Air in fuel system question

Topic: 1998 Foretravel U295 - Air in fuel system question (Read 8012 times) previous topic - next topic

Re: 1998 Foretravel U295 - Air in fuel system question

Reply #150 – August 12, 2025, 09:50:42 am

Quote from: rvquestion – August 11, 2025, 09:02:23 pm

Attached is a picture of how my water separator looks like
I don't have an actual picture

By the way the engine stayed running until the fuel ran out in the canister .
Lets remind i hade the solenoid plunger tied up with zip tie to keep the fuel valve open
I really don't know how much fuel i had in the canister , will guess may be 1.5 gallons
But when engine died , first i thought another problem is killing it
But soon found out the canister was empty
With little diesel left in it
A mechanic was supposed to come today and see where it is getting air from
But he didn't show up

Edmond

Yes, that Racor unit should be fine, I thought maybe you had the old Winn style filter system.

Re: 1998 Foretravel U295 - Air in fuel system question

Reply #151 – August 12, 2025, 10:07:10 am

Having fittings on will make it harder to pull the hoses threw. I bought a coupler and pushed the old hose
and the new hose together and that allowed me to pull the hose through.

Re: 1998 Foretravel U295 - Air in fuel system question

Reply #152 – August 12, 2025, 11:26:49 am

Thank you
A mechanic who was going to show up yesterday was trying to bypass the water separator in case if that is the source of the leak
He mentioned the clear glass section has the habit of getting cracked
I told him but it's completely dry and no diesel leak
He said " you will not see leak because there is suction there
He didn't show up claiming he was very busy
It could've been a good test to find out and make sure
By the way beside pressurizing the tank , is there any other way to suck all the air out of the long hose? I was told the reason it's still not staying running is because there is still air in the fuel supply hose, and by hand pumping may not be able to prime it properly

Regarding " sometimes the connector hung up"
What if the connector get wrapped with electric tape to give the Hose a smooth slide?

By the way since i want to have either prefabricated hoses or enough hose and connectors
I like to ask this question
What size is the fuel suply hose
What size is fuel return hose
What size is Gen. supply hose
What size is Gen. return hose
I know i need two connectors for each hose
Do you know which kind? What thread? Etc

Finally if you read my post about doing the replacement in phases, can generator hoses be pulled through on a later day ?
Or to do so the tank has to be out
As I mentioned, i can attach the new hoses to the tank and couple them with existing hoses, and let them lay on top of the tank
Will this work?
I understand nobody may have done this before

Edmond

Re: 1998 Foretravel U295 - Air in fuel system question

Reply #153 – August 12, 2025, 11:41:04 am

Quote from: rvquestion – August 12, 2025, 11:26:49 am

By the way beside pressurizing the tank , is there any other way to suck all the air out of the long hose?

Edmond

Sure, as long as the level of the fuel in the tank is higher than the filter head, diesel will naturally flow from tank to filter.

This can be achieved by either filling the tank, raising the front of the coach or temporarily lowering the filter head.

No need to totally remove the filter, just loosen it and tighten it when clean diesel with no bubbles flows out.

This can also be done in conjunction with slightly pressurizing the tank-- with the filter loosened, it takes a lot less PSI to make the diesel flow.

Re: 1998 Foretravel U295 - Air in fuel system question

Reply #154 – August 12, 2025, 11:55:41 am

The photo below is for a 2000 u320 4010. Not sure who posted this and when but for what it is worth.

Re: 1998 Foretravel U295 - Air in fuel system question

Reply #155 – August 12, 2025, 01:26:16 pm

Thank you both , hope the information on the 2000 U 320 is the same as 98 U 295
If I know the hoses sizes, I will do as one member posted, measure from the tank to the end of the bus and add 8 feet to it , and buy the correct fittings
I don't know the length of hoses going to generator

Regarding loosening fuel water separator, it makes sense to remove the mounting bolts of the filter
And loosen the filter a bit, then lower it down to the ground to be below the fuel tank level ( and pressurize the tank slightly if needed) and when it stopped, bubbling, tighten the filter and bring it back up and mount it
Did I understood it right Wolfe?

Edmond

Re: 1998 Foretravel U295 - Air in fuel system question

Reply #156 – August 12, 2025, 01:34:20 pm

Check fuel line prices it is cheaper to buy a 50' roll than 42' cut.

Re: 1998 Foretravel U295 - Air in fuel system question

Reply #157 – August 12, 2025, 02:09:52 pm

OK, but I like to know if the fuel supply and fuel return lines from engine are the same hole and have the same fittings

Re: 1998 Foretravel U295 - Air in fuel system question

Reply #158 – August 12, 2025, 02:44:23 pm

5/8" supply, 1/2" return

Re: 1998 Foretravel U295 - Air in fuel system question

Reply #159 – August 12, 2025, 03:06:11 pm

Thank you, Craneman
I don't mind to buy longer hose specially if it will be cheaper, but I need to make sure how much do I need?
The measurements from the U 320 post, does not indicate these lengths are for which length of Foretravel
For sure, 40 feet RV will take more hose than my 36
I will send an email to the dealers parts department. See if they can tell me by the VIN number.
So far what I learned is that the fuel supply for both generator and engine are 5/8
And the return line from engine is 1/2"
And the return line from generator is 3/8

If it was easy, I would have removed the existing hoses. Take them with me to a shop and have them make me identical hoses with identical fittings.

But since I cannot do that, I want to make sure that the fitting I am adding to the new hoses will connect to my tank and other connectors

It will be helpful if any of you guys can tell me or give me some knowledge about the connectors

Are they all standard in different sizes?? Are they different types? Do they come with different threads?
Maybe a link for each of them would make my job easier to just click and order

Hope I'm not expecting too much from you guys
million thanks
Edmond

Re: 1998 Foretravel U295 - Air in fuel system question

Reply #160 – August 12, 2025, 03:07:40 pm

My 99 ISC was 5/8 and 1/2", JIC 10 and 8. A friend's 98 non ISC( mechanical 300/325 was 1/2 and 3/8 JIC 8 and 6. So you will need to know for sure. Generator was 5/16 JIC 5 I think. As is said if you choose trident marine barrier hose. you may find it much cheaper to buy 50' rolls instead cuts from the local hose shop. Also be very careful to make sure the hose is rated for Bio Diesel. You may want to check, I don't think your generator feed is 5/8

Re: 1998 Foretravel U295 - Air in fuel system question

Reply #161 – August 12, 2025, 04:49:39 pm

I re-used all my fittings on the fuel line change out I did. Mine is a 320 and as Bruce pointed out your 295 may have different diameter fuel lines. The generator sizes would be the same as the post number 154

Re: 1998 Foretravel U295 - Air in fuel system question

Reply #162 – August 12, 2025, 05:53:14 pm

Quote from: rvquestion – August 12, 2025, 01:26:16 pm

Thank you both , hope the information on the 2000 U 320 is the same as 98 U 295
If I know the hoses sizes, I will do as one member posted, measure from the tank to the end of the bus and add 8 feet to it , and buy the correct fittings
I don't know the length of hoses going to generator

Regarding loosening fuel water separator, it makes sense to remove the mounting bolts of the filter
And loosen the filter a bit, then lower it down to the ground to be below the fuel tank level ( and pressurize the tank slightly if needed) and when it stopped, bubbling, tighten the filter and bring it back up and mount it
Did I understood it right Wolfe?

Edmond

YES, but lower it below tank level BEFORE breaking the seal on the filter. If you do it first, more fuel will run from filter head BACK to the tank.

Re: 1998 Foretravel U295 - Air in fuel system question

Reply #163 – August 12, 2025, 07:40:29 pm

Definitely,

Re: 1998 Foretravel U295 - Air in fuel system question

Reply #164 – August 12, 2025, 09:02:19 pm

I recommend that you do the generator fuel lines at the same time as it would a lot easier. It might be
possible to do the generator without removing the tank.
I sent the first picture so you can see where the fittings are but the U320 has two extra fittings.
Using string to tie up the hoses and gage wires makes the job easier as per second picture
The third picture you can see a piece of string which helps make sure the fuel pickup doesn't get kink.

Re: 1998 Foretravel U295 - Air in fuel system question

Reply #165 – August 13, 2025, 06:40:02 pm

I hear that the water separators like mine with clear glass on the bottom, have the habit of leaking air in the fuel system
If I bypass the water separator , will junks and particles be able to go inside the engine ?
or the fuel goes to the fuel pump a d then to the other filter before it gets in the injectors
This could help troubleshooting if the leak is from the water separator
Please advise

Re: 1998 Foretravel U295 - Air in fuel system question

Reply #166 – August 13, 2025, 07:04:26 pm

Where did you hear that your water separator has a habit of leaking. That is a very good filter system. If the plastic bowl was cracked, then you would be able to feel fuel on it when you ran your hand over it. I think that you need to pressurize the tank enough to get fuel back to the filter, then tie up the fuel solenoid and start it up. Let it run for a while. Untie the fuel solenoid and see if it keeps running. Then if it does turn it off. Let it sit for 5 minutes and then try to see if it starts and keeps running. You have to narrow down the problem and quit jumping around replacing this part and then that part. It is pretty expensive to keep throwing parts at it. While you have it running push the raise button and then let it fully raise turn off ignition and put in your safety stands. That way you can get under it to work on fuel lines if that is what is wrong. Definitely replace the generator fuel lines at the same time.

Re: 1998 Foretravel U295 - Air in fuel system question

Reply #167 – August 13, 2025, 07:21:44 pm

One of local mobile mechanics told me about the water separator habit
I'll follow your advice
Thank you

Re: 1998 Foretravel U295 - Air in fuel system question

Reply #168 – August 14, 2025, 12:24:45 pm

I like to find out where the fuel return check valve on my mechanical 8.3 is located?
Pictures can help more if possible
Thank you

Re: 1998 Foretravel U295 - Air in fuel system question

Reply #169 – August 14, 2025, 01:53:52 pm

Quote from: rvquestion – August 14, 2025, 12:24:45 pm

I like to find out where the fuel return check valve on my mechanical 8.3 is located?
Pictures can help more if possible

I only found one reference to "fuel return check valve" on C8.3 engine, in the old Lewis Anderson post linked below. Read down toward the middle of the LONG post for the entry dated 10 June 2016:

Low Power From Engine

Looking up part number 3924726 brings up the page linked below. Isn't this the same check valve you already ordered (before you ordered the overflow valve)?

'89-'98, 12V Dodge Cummins Fuel Return Check Valve.

See your Reply #89 from 2 weeks ago:

1998 Foretravel U295 - Air in fuel system question

Photo of my engine below, from when I replaced a leaking fuel line. This is the passenger side of engine. You can see the drain line (Ref #4 in parts diagram) coming across the top of the valve cover. It connects to the fuel filter mounting assembly with what is called a "check valve" (Ref #16 in the parts diagram). I think this "check valve" is the "fuel return check valve" that you seek.

Re: 1998 Foretravel U295 - Air in fuel system question

Reply #170 – August 14, 2025, 04:27:52 pm

I changed the return check valve on the Monaco. I noticed one morning that I had less power and
when I got home I did some trouble shooting and it looked like the valve was the problem so I changed
it and the power come back. I don't think it would just shut the engine down and if it did I don't think
it would start up again.

Re: 1998 Foretravel U295 - Air in fuel system question

Reply #171 – August 14, 2025, 04:50:56 pm

Another hose replacement preparation question
Let's say the fuel tank is out, and the hoses are connected before pushing the tank in how to make sure that there is no leaks from connectors because you don't want to wrap up everything, fill up the tank and then find out that there is some leak on the hoses

Re: 1998 Foretravel U295 - Air in fuel system question

Reply #172 – August 14, 2025, 05:34:36 pm

Just due diligence when assembling. The hose has to be pushed all the way into the hose and then the flare fittings are tight. At that point you have done all that is necessary.

Follow-ups
- Out by the coach

Re: 1998 Foretravel U295 - Air in fuel system question

Reply #173 – August 14, 2025, 08:20:31 pm

Can lubricant be used to push the connectors inside the hose??
Does anyone know if the existing connectors will fit Trident hoses?

Re: 1998 Foretravel U295 - Air in fuel system question

Reply #174 – August 14, 2025, 08:49:18 pm

I used a heat gun to soften the hoses and used the same push on fittings I removed. No leaks after the installation years ago.

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