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+--- Thread: Another bad crossover valve. (/showthread.php?tid=3394)
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Another bad crossover valve. - dhirocz - 08-09-2018
Had a bad day.
I started having fuel levelling problems dropping down out of WV on 77. Found most of my fuel moved to the passenger side tank. I replaced the valve and ALL fuel hoses last year.
Stopped and transferred fuel to the driver's side tank in Wytheville, removed and cleaned the vents. These were also replaced last year. Had to fight the passenger side to get it back in.
Stopped for fuel in Rock Hill, SC. Found 60 gal in passenger tank, driver's tank on fumes. Then the lift pump quit. Took almost 2 hours to find a bad electrical connection and fix it at the damn fuel island.
Lost 4 hours total, left and found all my fuel in the passenger tank again so I shut it down right down the road.
...aside from having a jacked up day, I replaced this crossover valve once already...and all the lines...and it's doing this again. It's not much more than a tee really...but it insists on returning all of the fuel to the passenger tank. So either this valve failed me again, or I'm missing something.
I'll be taking this back home tomorrow...is there something I may be overlooking here? That valve is basically just a tee with a simple backflow device in it, could that really be doing this?!? Has anyone put in a more simple tee maybe?
RE: Another bad levelling valve. - Unilevers - 08-09-2018
any kind of kink or restriction or too sharp a bend causes more restriction and returns more to the other tank. make sure there isnt any of those. what i did because i got tired of dealing with this on one problem truck is i just had bungs put in the bottom of the tanks and ran a hose across from both tanks to manually level them out it returned more fuel to one than the other. Many trucks dont have this issue but it seems that once you do it plagues you.
RE: Another bad crossover valve. - dhirocz - 08-09-2018
I have considered this, but haven't really thought about it until it became a problem again today.
I'm going to be taking the hoses back off to verify they are good and free flowing, maybe I got a bad length of hose...but I doubt it. I went top shelf on having those made.
I do have drains on the bottom of both tanks, that are fairly well protected by the tank brackets. I could run a JIC elbow to a crossover tube, up to the frame and around the crossmember and down to the other tank, but I'd rather get it working properly (if I can) first.
Why not control return flow restriction with a ball valve in the return on the top of the tank? It would take a little bit of fudging with it, but I could remove the crossover and replace with a standard tee and adjust the return rate manually if needed, and be able to isolate a tank in the event of a leak or failure as well...
RE: Another bad crossover valve. - Kid Rock - 08-09-2018
There could be a suction line blocked in one of the tanks? We ran out of fuel once in Dallas after putting in 40 gallons or so to get us to the big discount fuel spot, all the fuel went to the passenger tank and luckily a mobile repair guy was driving by and stopped and went and got diesel for us. After that, I told myself “not again”, so I got ball valves on and closed one tank and decided to just run on the one tank that has the level sensor in it.
It can be a little inconvenient at times, and adds a little more work to filing ifta with the extra reciepts, but oh well, that’s what we did.
RE: Another bad crossover valve. - dhirocz - 08-10-2018
...this is a pain in the butt. I've got to stop every 30 miles and transfer fuel back to the driver's tank or it'll run out all over the ground. Yeah, it's getting a couple new vents and a valve today at a minimum.
RE: Another bad crossover valve. - Rawze - 08-10-2018
(08-10-2018 )dhirocz Wrote: ...this is a pain in the butt. I've got to stop every 30 miles and transfer fuel back to the driver's tank or it'll run out all over the ground. Yeah, it's getting a couple new vents and a valve today at a minimum.
Also check your vent tubes to ensure they are not partially clogged.
RE: Another bad crossover valve. - dhirocz - 08-10-2018
No, I cleaned them out with the vents and the hoses aren't that old. but after using the passenger side vent to push fuel to the driver's side, I notice it sometimes like to hold pressure in the tank... I bet it is the problem.
RE: Another bad crossover valve. - snailexpress - 08-10-2018
You have air intrusion in fuel tank equalizing system.
If system is air tight fuel will be siphoned from tank with higher level to the lower until equalized.
If siphon is breaks fuel will go to the tank with less restriction to flow. Due to road crown it's always passenger side.
[attachment=4134]
RE: Another bad crossover valve. - dhirocz - 08-10-2018
I ordered two new tank vents, gaskets, and I picked up a new high flow crossover valve that is supposed to help with balance issues. Ill check out the system and we will see where that leads us.
One of those vents was suspect so they'll both just be replaced again.