That was my problem but with both tanks took the bed off install two new pumps, I don’t care I am pushing 75 years old and handicap and took me almost a week to do the job but it works perfect now I can chase that rich widow woman that lives down the street, thanks for the information to do the job
The problem is the OEM factory pumps are known for those check valves to go bad and so Ford made two inline valves (PN Genuine Ford Connector 1L3Z-9J274-BA) to fix this issue. Some people have them and some people don't just depends at the time of the recall if the vehicle was taken in. I had/have this same issue with my 93 f150 with the 4.9 L. I realized very recently that when I had replaced both sending units that I damaged one of the valves on the rear tank (which is my tank that is overflowing). So if you get that part, put it on the return coupling on the tank you're having issues than that should fix it. Recall # is 01l008000.
Thanks very much for the info. I just replaced both pumps on my 94 F150 and my front tank is transferring the fuel to to the rear. My truck doesn’t have the tank selector valve from factory so this must be the problem as you decried. I’ll pull the bed back off and check. The truck will run but only off the rear tank. Fuel is transferring from the front tank only so must be the wrong pump.
Yeah brother.... I'd been there never got the tee shirt and coke deal.LOL, However my license did & are actively suspended for the next 5 years over that day. Wish I knew all this then. Keep up the good info. Be safe
Thánks for illustrative video! I have a F150 1989 4.9 lts dual thank configuration, AND lately hace the dame issue with the front thank overflow when rear thank Is in use. The gas spills over the feeding gas hose after a while use of rear thank. So It could be work yo install an external check Valve on one of the thank out hoses? Thánks for your help!!
Great video! Question: I just replaced rear gas tank which was working; kept everything the same except for tank and filler neck; now car won’t start when I filled her up. Front tank has been unusable, starts up and dies reads empty but rejects gas when I try to fill so I’m not sure if I’m having the check valve issue. I’ve always just used the rear tank and it runs fine. What else could I try to get the car started, I’m going after the schrader valve tomorrow, couldn’t get the cap off
So the front tank needs a double check valve. The front tank pump needs a check valve on the inlet to the pump. So that when the front pump is off the ceck valve will stop the backflow through the pump. Same thing on the back tank as well the pump will need to be on the live pressure line like the front one with a valve to block the pressure from the other pump pushing gas back into the tank through the pump. The valve on the pressure side of the pump should open and close to let the return gas back into the appropriate tank if its working correctly on both pumps.
Good video, thanks! To be clear, you only replaced the front tank pump, correct? My ‘94 has the exact same problem. Mine is leaking gas overflow at the filler hose. Maybe I need a new filler hose, that rubber is 28 years old! I will buy an oem replacement pump if they are reasonable and available.
Lol. I did about the same thing for awhile, but the fuel gauge didn't work either on my front tank as well as would overflow if using the rear tank so it was always a guessing game on the front.
Im having a similar issue with my 95 f350 gas engine. Just put a new front fuel pump and new tank. But gas keeps flowing to the rear tank. The rear fuel pump is bad. It don’t even come on when I flip the switch. Would you recommend replacing the rear pump or would I be better off canceling it. Kinda just want to run on the front tank since it’s new. Thanks.
Yes rear pump is bad. Those check valves I spoke about in the video are leaking, that's why your rear tank is filling up. To stop that without replacing the pump you would have to cap off both lines near the rear tank somehow. Side note: if you plan to replace the pump only and have someone to help you, it is actually easier (in my opinion) to take the bed off, especially if the tank is full, tank gets pretty heavy when its full, plus the connections can be difficult to get to when lowering the tank. The bed is 6 bolts holding in on, the small screws and hose clamp near filler neck holding the filler neck and a couple plugs in the back for the tail lights, have a friend help you lift it off and the rest is cake. Plus you can pump any old nasty fuel out of it at that time if it has been in there for a long time. I have a long bed and it isn't to bad, not as heavy as one might think. Also note when you get the new pump, before you do anything else, blow into both lines on the pump, you should not be able to blow air through either side. If you can it's likely the wrong pump. You can also do that on the old pump and you should be able to see what I'm talking about if you can blow air through it.
If your front tank is over flowing then your front tank pump assembly is malfunctioning/ which contains those check valves. You could test it by blowing low pressure air through both of the lines like I described, if they leak by then the whole assembly would have to be replaced. There isn't really any way to replace or repair the check valves alone.
Here's something else i learned messing with the bad fuel pump issue... if you're getting low fuel pressure codes when you replace your pump follow "ford tech makuloco" 's advice and drain the memory on your PCM by jumping your positive battery terminal connected tour battery to your negative battery terminal disconnected from the battery for @ 10 minutes then hook it back up and star yhe engine with everything else turned and let PCM "learn" how to idle t it warms up, then go for a mellow cruise for 10 miles or so and then get it up to highway speed to let your PCM reset your shift points and your fuel trims... it will get rid of any erratic shifting and bad fuel delivery habits the PCM picked up while your truck was throwing codes... it made my truck run and shift alot smoother after I did that !!
I'm having the same issue but on the opposite pump it's overflowing into my rear tank I bought a check valve So I put it on the smaller line going into the front fuel pump correct which direction
I think you kind of got it wrong because my 92 that I have the check valves are on the fuel line they put a check valve on the return line on the rear tank in the front tank and it prevents it from filling up the opposite tank
Ok… but I just replaced my front pump and now when I’m using my front tank my rear tank overflows AND when I’m using my rear tank I’m getting fuel pumped in my front tank..?? So how could both sending units check valves go at the exact same time..??? 1995 f150 4.9 l Eddie Bauer
It may be possible that the rear is just getting worn out and the front one you just replaced isn't the correct one. ( This may seem crazy, but. It's kinda easier to remove the truck bed to get to them if you have a friend or two that can help lift it off. It really isn't that heavy, even an 8ft bed. It's just 4 bolts holding it down, disconnect the filler neck hoses and unplug the wiring harness for the taillights. I did one of mine that way with just one friend helping to lift it up and back off. Sit it on some saw horses.) I had to do one of mine 3 times before I figured out what was wrong. You can blow into both tubes on the pump, you shouldn't be able to blow through them on either of the two tubes going into the pump.
Unfortunately there is no real way to. Just try blowing into both tubes when you get it, before you even start disassembling anything. You should not be able to blow air through either one
can you tell me which brand to buy that has the correct internal check valves for my 1996 f150 5.0l styleside single cab steel 19G side tank? i bought an skp sending unit/pump assembly for $70 and I can blow right through the return pipe on it.
@@jpvjjohnny ok, I thought so, that's the only place I've seen that brand. So it is honestly hard to say. I had the same issue I got the "wrong" pump from Rock Auto and is the one I had shown in the video, which is why I decided to do this video. I would have thought that selecting a 1996 that I would have gotten the correct one from them, but it didn't work out that way. They have so many different brands, it's difficult to be sure you get the correct one. I can tell you that it is very very important to be certain that you get the correct one for the fuel tank size that you have. A 17 gallon pump may fit, but will not sit correctly inside the tank of a 19 gallon tank, or vice versa. If I remember correctly I think I ended up getting a Delphi pump and it was correct. Hope this helps, and good luck, it can be a bit of gamble with them on this one. I use them pretty much for everything, but this one was difficult to figure out on their site.
I replaced the oem pump in my front tank with the SKP pump because the one that was in there had such low fuel pressure and the quantity circuit aways showed empty even if the tank was full to the brim.. now it pumps good pressure and the gas gauge works good, but when i run on the rear tank it dumps fuel to the front quicker than ever... but at least the front tank pumps good so i have to run the front tank down to under half before i can run the rear pump which goes low real quick then back to the front tank til it gets low again, and then only add new fuel to the system in the rear tank. I thought the delphi pumps on there were just the pump body only.. so how do you get the "retainer" (the metal tubes) off of the old pump without breaking something? I figure the front pump will get run alot more with no return line check vave in the pump body, but at least i can figure out my mpg now if i top off the front tank and run it only for 100 miles and then top it off again. Thanks dk Dain your video showed the secret to the trouble... i just wish if you ordered a pump for a 1996 it would be built to match the oem configuration but it is what is... just a quirk a driver will have to learn to work around
I need your help on the harmonic balancer video I did the same process as you but after re Installing truck won’t fire only cranks. Any advice? Will it not start if I didn’t torque it down enough?
I bought a msd pro billet. Distributor a msd 6al digital box and msd coil after installing truck wouldn't pulse Injectors how do I make this all work I'm seriously about to trash aaall this FI and get a carb please help
@@RollingThunder85 unfortunately without being able to see everything myself, I'm not likely going to be able to help. Aftermarket is almost always a gamble
@@dkdain9002 the old distributor sent a signal to the pcm when to fire the injectors the new distributor doesn't do any of that, what are your thoughts on a FI to carb swap? This is a pulling truck going up and over a small MTN range from Portland to sand dunes I need power not mileage ?
No real way to know the part numbers. They can be different for different brands. No, front and rear tanks are different pumps. They are identified by year and tank size as well as steel or plastic tanks.
A fuel pump is constantly running while the engine is running. Which means that fuel is constantly flowing from the tank to the engines fuel rail (on fuel injection types) and then back to the fuel tank. Basically fuel is flowing in a constant loop. The engine only uses what it needs from the fuel rail as it needs it, higher RMP's need more fuel and less fuel at idle. So in other words "blocking off" the return would over pressurize the the fuel system in that "loop" most likely causing the fuel pump to fail from being over worked from trying to constantly pump fuel that isn't flowing like it should. So no.... I suppose you could on the tank and fuel pump that isn't being used. But I personally would not recommend it.
@@dkdain9002 8i was asking because i was removing my electric pumps for my 12 valve and there were no pumps in the tank. the connector had 4 wires terminated on the outside but only one on the inside, fuel sending unit. works out good for me. Thanks for the response, good video.
@@dkdain9002 no my diesel has what Ford calls a lift pump it operates from the camshaft bolted to the top of the motor... the tank switch has 4 lines in from the 2 tanks, supply and return .. the tank switch then has only 2 lines going to the motor.. supply and return... the tank that is in use is the tank that the fuel from the return line will go to.. .... ..I thought gassers had this same switch.... I would be willing to bet your problem is in the tank switch... it's stuck in the forward tank and only letting fuel return to that tank.. ... there should not be any restrictions on the return line.. if there's a one way valve on the return it probably is to keep fuel from going out through return line...
@@brianturck274 ok. Yeah I am not familiar with the diesel models. The gassers work differently then. The gassers work as I described in the video. Replacing the front fuel pump fixed the issue due to the internal check valves that open with the fuel pressure of the pump that is in use and closes off when that pump isn't running and in use. As I've shown in the video and after disassembling the old pump and comparing it to the new correct pump (not the "new one" in the video) I learned and know now exactly how they work. / my fuel switch works as it should.
I just replaced both my pumps on my 95 and they are filling each other up and causing my gas to run out fast cause they are going back and forth from tank to tank , can anybody give me some advice
@@ebaht7468 I usually use rockauto.com, but you have to be very careful and mindful about which one to get. You have to know for certain what size and type of tank you have, (plastic or steel). The only way to know what size tank you have is either looking it up by the vin or exact model. Or run it dry and fill it up to see how much it takes to fill it up, but I would not advise that if your other tank doesn't work.
