Big Blue's Transformation

[Gary Lewis]

Measured the skid plate under Camano and it's roughly 63.5" following the contours.

I get 63" on this one following all the contours, and it is 12 1/2" wide. So it is probably the same one as yours. It looks like the one in this illustration:

[Gary Lewis]

I get 63" on this one following all the contours, and it is 12 1/2" wide. So it is probably the same one as yours. It looks like the one in this illustration:

Ok, on another tack, how badly do I need the check valves that were added to the FDM's as part of a TSB? Wouldn't the later FDM's be upgraded to include the check valve?

I got off one of the two that were on Huck's FDM's, but the other doesn't really want to come and the little catches don't look easy to release. So, do I really need them?

And, here's what they look like - rusty:

[Nothing Special]

Ok, on another tack, how badly do I need the check valves that were added to the FDM's as part of a TSB? Wouldn't the later FDM's be upgraded to include the check valve?

I got off one of the two that were on Huck's FDM's, but the other doesn't really want to come and the little catches don't look easy to release. So, do I really need them?

And, here's what they look like - rusty:

From what I understand the external check valves are only needed if the internal check valve leaks. A belt-and-suspenders thing. The original check valves were pretty likely to leak, but I'd think a new FDM should be better.

For what it's worth, understanding the failure mode makes it a lot easier to deal with a failure. If a check valve leaks it will return fuel to the tank that's not being used. If that tank is already full you'll end up overfilling the tank and dumping gas out of the vent. But if the tank is empty you'll just run the tank you're using out of gas quicker than you thought, bust will still have the gas, now in the tank with the bad check valve.

I lived with that situation in my '95 F-150 for the last year or so that I owned it. I just always used the "bad" tank first.

And now I MIGHT have the same thing going on with my '97. Seat-of-the-pants it feels like I'm getting worse mileage on the rear tank, and when I switch to the front tank (if I use the rear first) the gauge is pegged way past the "F". But I check my mileage, and the actual numbers don't make it as obvious that the mileage is different between the tanks. And if I run the front first it doesn't seem to be more full than I left it after I run the rear.

But that's the kind of issues you deal with if you have a leaking check valve in an FDM. Is it a good idea to have an external check valve as insurance? Maybe. But I'm not bothering with it.

[Gary Lewis]

From what I understand the external check valves are only needed if the internal check valve leaks. A belt-and-suspenders thing. The original check valves were pretty likely to leak, but I'd think a new FDM should be better.

For what it's worth, understanding the failure mode makes it a lot easier to deal with a failure. If a check valve leaks it will return fuel to the tank that's not being used. If that tank is already full you'll end up overfilling the tank and dumping gas out of the vent. But if the tank is empty you'll just run the tank you're using out of gas quicker than you thought, bust will still have the gas, now in the tank with the bad check valve.

I lived with that situation in my '95 F-150 for the last year or so that I owned it. I just always used the "bad" tank first.

And now I MIGHT have the same thing going on with my '97. Seat-of-the-pants it feels like I'm getting worse mileage on the rear tank, and when I switch to the front tank (if I use the rear first) the gauge is pegged way past the "F". But I check my mileage, and the actual numbers don't make it as obvious that the mileage is different between the tanks. And if I run the front first it doesn't seem to be more full than I left it after I run the rear.

But that's the kind of issues you deal with if you have a leaking check valve in an FDM. Is it a good idea to have an external check valve as insurance? Maybe. But I'm not bothering with it.

Thank you! That's what I felt as well, but didn't want to lead the witness.

If I understand correctly, the fault is that the check valve on the supply side fails. It is meant to prevent fuel coming in to Tank A when Tank B's pump is energized. So they just stick this additional check valve on the outside to stop the backflow.

Given that, with one valve if I have a problem down the road I can pull the line and put the valve on the tank whose check valve is leaking. I think I'll just wait and see if I have a problem.

Thanks!

[85lebaront2]

Ok, on another tack, how badly do I need the check valves that were added to the FDM's as part of a TSB? Wouldn't the later FDM's be upgraded to include the check valve?

I got off one of the two that were on Huck's FDM's, but the other doesn't really want to come and the little catches don't look easy to release. So, do I really need them?

And, here's what they look like - rusty:

Gary, there is a tool that slides over the line and goes up inside the check valve to open the "teeth" that lock it to the outlet line. When I replaced the front FDM on Darth my full coverage disconnect set had the correct release tool.

[Gary Lewis]

Gary, there is a tool that slides over the line and goes up inside the check valve to open the "teeth" that lock it to the outlet line. When I replaced the front FDM on Darth my full coverage disconnect set had the correct release tool.

Thanks, Bill. I'll keep that in mind if I have to pull that one off.

[Gary Lewis]

Thanks, Bill. I'll keep that in mind if I have to pull that one off.

I have a question for y'all, down below. But let me pose it here - before you know the specifics: What should I use to protect the tanks from the straps and the skid plates.

Well, today was four steps forward and one back. The first step forward was that when we backed out of the garage this morning both of the new tanks were in the driveway.

The step back was that the guy at the salvage had not only cut the outside hose to the rear filler neck, but he'd cut the inside hose! And there's no way to get up in there and get the remaining hose out. In fact, on the front tank's filler neck you can see a crimped hose clamp waaaaaay up inside the neck, far out of reach.

Bobby, the guy at the salvage said "Just put a hose barb in and extend the hose." But that's going to reduce the fuel flow and I'm not willing to do that. So I rejected that one and ordered a SCITOO E7TZ9034B FN725 Fuel Tank Filler Neck Pipe Tube. There were less expensive ones, but they wouldn't get here for two weeks, and this one is to be here Sunday.

The next step forward was when I stopped by the post office and they had the front fuel delivery module. Didn't appear to have any plans to deliver it, in spite of the statement on the sticker they left that said they would two more times. And that confirms what a friend had said - with this post office you get one strike and you are out. I sure hope Amazon or UPS outsources USPS some day.

The next step forward was when we got home - the two fuel filler hoses were on the front porch.

And the last step forward was when the rear tank & skid plates went in, as shown below. But it wasn't as easy as it sounds. First, the tank won't go in with the trailer hitch in place, and that hitch is too heavy for me to hold up while I pull all six bolts. So I set it down on the tool box with the lift, removed the bolts, and picked the truck up. Then I did basically the reverse to put the tank and skid plates, plural, up there. It isn't exactly in the perfect position, but a bit of tweaking will get it there.

But that brings me to my question - how to protect the tanks. The front/mid-ship tank will be up against a crossmember at the top and held in place by straps going under the tank. The rear tank goes up against straps at the top, and is held in place by the skid plates. The MPC shows the insulators as 9240 and says " INSULATOR (FUEL TANK)" and then says "improvise unless listed below". But, it doesn't say what they are made of.

I have a motorcycle inner tube and am considering using strips out of it to protect the tanks. Will that work? Is there something better?

 

[ArdWrknTrk]

I have a question for y'all, down below. But let me pose it here - before you know the specifics: What should I use to protect the tanks from the straps and the skid plates.

Well, today was four steps forward and one back. The first step forward was that when we backed out of the garage this morning both of the new tanks were in the driveway.

The step back was that the guy at the salvage had not only cut the outside hose to the rear filler neck, but he'd cut the inside hose! And there's no way to get up in there and get the remaining hose out. In fact, on the front tank's filler neck you can see a crimped hose clamp waaaaaay up inside the neck, far out of reach.

Bobby, the guy at the salvage said "Just put a hose barb in and extend the hose." But that's going to reduce the fuel flow and I'm not willing to do that. So I rejected that one and ordered a SCITOO E7TZ9034B FN725 Fuel Tank Filler Neck Pipe Tube. There were less expensive ones, but they wouldn't get here for two weeks, and this one is to be here Sunday.

The next step forward was when I stopped by the post office and they had the front fuel delivery module. Didn't appear to have any plans to deliver it, in spite of the statement on the sticker they left that said they would two more times. And that confirms what a friend had said - with this post office you get one strike and you are out. I sure hope Amazon or UPS outsources USPS some day.

The next step forward was when we got home - the two fuel filler hoses were on the front porch.

And the last step forward was when the rear tank & skid plates went in, as shown below. But it wasn't as easy as it sounds. First, the tank won't go in with the trailer hitch in place, and that hitch is too heavy for me to hold up while I pull all six bolts. So I set it down on the tool box with the lift, removed the bolts, and picked the truck up. Then I did basically the reverse to put the tank and skid plates, plural, up there. It isn't exactly in the perfect position, but a bit of tweaking will get it there.

But that brings me to my question - how to protect the tanks. The front/mid-ship tank will be up against a crossmember at the top and held in place by straps going under the tank. The rear tank goes up against straps at the top, and is held in place by the skid plates. The MPC shows the insulators as 9240 and says " INSULATOR (FUEL TANK)" and then says "improvise unless listed below". But, it doesn't say what they are made of.

I have a motorcycle inner tube and am considering using strips out of it to protect the tanks. Will that work? Is there something better?

Wow, that's a Purdy diff cover!

I wish mine had a drain.

I think rubber would be fine.

When I had my side tank down I used some thick polyethylene, as I knew it would not soften or absorb anything (like the webbing Ford used)

I've don't think ive seen two piece skid plates.

That's an interesting touch.

 

[Gary Lewis]

Wow, that's a Purdy diff cover!

I wish mine had a drain.

I think rubber would be fine.

When I had my side tank down I used some thick polyethylene, as I knew it would not soften or absorb anything (like the webbing Ford used)

I've don't think ive seen two piece skid plates.

That's an interesting touch.

 

Thanks, Jim. I'll use the rubber.

The split skid plates are off Dad's truck, but I don't really want to use them on that truck, so will use them on Big Blue.

And the diff cover was installed at Vernon's request - and I've checked the main cap supports and they were improperly adjusted.

[85lebaront2]

Wow, that's a Purdy diff cover!

I wish mine had a drain.

I think rubber would be fine.

When I had my side tank down I used some thick polyethylene, as I knew it would not soften or absorb anything (like the webbing Ford used)

I've don't think ive seen two piece skid plates.

That's an interesting touch.

 

Jim, when I did the disc conversion and ended up having to do the ring and pinion on his 10.25" I drilled and tapped a 3/8 pipe hole in the bottom of the casting. I put a hex socket pipe plug in and it is nearly flush with the casting. Drain plug is circled in the picture and is in the lowest point in the housing.