1985F20 SuperCab "REDRUM"

[CRittaler]

I will have a look! I have another 87+ tank that has a pump assembly so I will compare it with my current one.

good to know the lower end of the hose isn't constrained. I probably didn't need to replace the tank then, oh well may as well now since I have it.

The filler neck I have has the inner hose already attached at the top, I'll take a closer look.

If I can get away with just removing a tab on the assembly, even better.

Should be able to test drive the truck tonight.

I finished swapping the rear tank, I didn't have to do anything with my sending unit tabs, they lined up just fine, not sure what was going on there, but it was a nice surprise. I for sure ordered a sending unit for pre 87 from LMC so I don't know why it worked out.

If you're standing looking at the tank with the pump assembly closest to you, the fuel outlet was at ~5 O'clock and the return was at ~7:30 This was the same on both tanks.

I did have to bend the float rod a bit to get it to land on E with 5 gallons in the tank. After that I wrestled it back into place.

New fill neck fit nicely and it all bolted together fine.

I also reconnected power to the in tank pumps and bypassed the aftermarket pump on the frame rail.

I started the truck and it ran without shutting off. Tried both tanks, it didn't die. We'll see how it goes when I can putter around a bit though.

I think I was right in the the frame mounted pump was losing it's prime while sitting and sometimes wasn't able to reprime before the float bowls would run empty. This pump is mounted on the frame rail up by the transfer case so there is quite a bit of fuel line that it would have to pull through to reprime.

[ArdWrknTrk]

Should be able to test drive the truck tonight.

I finished swapping the rear tank, I didn't have to do anything with my sending unit tabs, they lined up just fine, not sure what was going on there, but it was a nice surprise. I for sure ordered a sending unit for pre 87 from LMC so I don't know why it worked out.

If you're standing looking at the tank with the pump assembly closest to you, the fuel outlet was at ~5 O'clock and the return was at ~7:30 This was the same on both tanks.

I did have to bend the float rod a bit to get it to land on E with 5 gallons in the tank. After that I wrestled it back into place.

New fill neck fit nicely and it all bolted together fine.

I also reconnected power to the in tank pumps and bypassed the aftermarket pump on the frame rail.

I started the truck and it ran without shutting off. Tried both tanks, it didn't die. We'll see how it goes when I can putter around a bit though.

I think I was right in the the frame mounted pump was losing it's prime while sitting and sometimes wasn't able to reprime before the float bowls would run empty. This pump is mounted on the frame rail up by the transfer case so there is quite a bit of fuel line that it would have to pull through to reprime.

I'm glad it worked out for you Chris!

I had issue with my sender clocking, but I don't have the in-tank pump.

Maybe there's a difference?

For my side tank I just ordered the '80-'86 tank and cut out the vent tube loop.

The '80-'86 sender fit fine.(as it should)

 

[Gary Lewis]

I'm glad it worked out for you Chris!

I had issue with my sender clocking, but I don't have the in-tank pump.

Maybe there's a difference?

For my side tank I just ordered the '80-'86 tank and cut out the vent tube loop.

The '80-'86 sender fit fine.(as it should)

Yes, glad it worked!

[CRittaler]

Should be able to test drive the truck tonight.

I finished swapping the rear tank, I didn't have to do anything with my sending unit tabs, they lined up just fine, not sure what was going on there, but it was a nice surprise. I for sure ordered a sending unit for pre 87 from LMC so I don't know why it worked out.

If you're standing looking at the tank with the pump assembly closest to you, the fuel outlet was at ~5 O'clock and the return was at ~7:30 This was the same on both tanks.

I did have to bend the float rod a bit to get it to land on E with 5 gallons in the tank. After that I wrestled it back into place.

New fill neck fit nicely and it all bolted together fine.

I also reconnected power to the in tank pumps and bypassed the aftermarket pump on the frame rail.

I started the truck and it ran without shutting off. Tried both tanks, it didn't die. We'll see how it goes when I can putter around a bit though.

I think I was right in the the frame mounted pump was losing it's prime while sitting and sometimes wasn't able to reprime before the float bowls would run empty. This pump is mounted on the frame rail up by the transfer case so there is quite a bit of fuel line that it would have to pull through to reprime.

I ended up just replacing the front tank as well, so now I have both tanks new and new fill necks.

It ended up working well, though I have to angle the nozzle a certain way when filling the front tank or it will spit back at me.

Truck did well on another road trip to Canada. I picked up some car parts that I had left at my moms.

3 boxes of parts from my 1968 BMW 2000CS that I had to scrap and 2 7.25 drum to drum rear ends for my dart.

During the trip we drove from Victoria to Parksville and the truck managed ~11mpg

Next up on stuff to fix, speedometer is ~10% slower than actual speed. I suspect it's a bad cable since the rear end ratios are the same, but there's a chance that the PO didn't change the gear on the cable and I don't know if the drive gear is the same between the ZF5 and the original C6(?)

[ArdWrknTrk]

I ended up just replacing the front tank as well, so now I have both tanks new and new fill necks.

It ended up working well, though I have to angle the nozzle a certain way when filling the front tank or it will spit back at me.

Truck did well on another road trip to Canada. I picked up some car parts that I had left at my moms.

3 boxes of parts from my 1968 BMW 2000CS that I had to scrap and 2 7.25 drum to drum rear ends for my dart.

During the trip we drove from Victoria to Parksville and the truck managed ~11mpg

Next up on stuff to fix, speedometer is ~10% slower than actual speed. I suspect it's a bad cable since the rear end ratios are the same, but there's a chance that the PO didn't change the gear on the cable and I don't know if the drive gear is the same between the ZF5 and the original C6(?)

Chris, there's been some discussion in another thread about auto to manual driven speedo gears. https://forum.garysgaragemahal.com/Speedo-cable-driven-gear-color-code-tp138631.html

Gary put up a chart but obviously it wouldn't include a Zf, and mine is 4x4 so my speedo drive remained in the TC.

It would definitely help if you could determine the colour of the drive gear.

Sounds like a successful trip with reasonable milage depending on your rear ratio.

[Gary Lewis]

Chris, there's been some discussion in another thread about auto to manual driven speedo gears. https://forum.garysgaragemahal.com/Speedo-cable-driven-gear-color-code-tp138631.html

Gary put up a chart but obviously it wouldn't include a Zf, and mine is 4x4 so my speedo drive remained in the TC.

It would definitely help if you could determine the colour of the drive gear.

Sounds like a successful trip with reasonable milage depending on your rear ratio.

Right, it would be good to know what gear you currently have. You need that info to figure out what gear to put in to correct the problem.

Speaking of the problem, if the speedo is off 10% then the odo is probably off that much as well. So if you based your 11 MPG off of the odometer then you may have actually been at 12. And while 11 is pretty good for a 460, 12 is even better!

[CRittaler]

Right, it would be good to know what gear you currently have. You need that info to figure out what gear to put in to correct the problem.

Speaking of the problem, if the speedo is off 10% then the odo is probably off that much as well. So if you based your 11 MPG off of the odometer then you may have actually been at 12. And while 11 is pretty good for a 460, 12 is even better!

unfortunately, I added 10% to the mileage before calculating lol.

I do notice the needle bouncing so I might also try lubricating it. What should I use? Graphite dry lubricant or Lithium grease?

[Gary Lewis]

unfortunately, I added 10% to the mileage before calculating lol.

I do notice the needle bouncing so I might also try lubricating it. What should I use? Graphite dry lubricant or Lithium grease?

I tried graphite and Teflon, but neither took the bounce out. So I used Mobil 1 synthetic bearing grease and that did the trick. And it worked through the winter as well.

[ArdWrknTrk]

I tried graphite and Teflon, but neither took the bounce out. So I used Mobil 1 synthetic bearing grease and that did the trick. And it worked through the winter as well.

I've had trouble with thick grease in winter.

But I didn't use mobil-1 synthetic like Gary did.

I'd be more inclined towards a thixotropic grease like '00' grease from Stens, Oregon or John Deere..

This is what most people use in snowblowers.

I have Cable Life and a pressure luber from way back when motorcycles had clutch and brake cables, so that's what I use.

[Gary Lewis]

I've had trouble with thick grease in winter.

But I didn't use mobil-1 synthetic like Gary did.

I'd be more inclined towards a thixotropic grease like '00' grease from Stens, Oregon or John Deere..

This is what most people use in snowblowers.

I have Cable Life and a pressure luber from way back when motorcycles had clutch and brake cables, so that's what I use.

If you just have a little bounce I’d start out with something like Jim suggested and keep the synthetic wheel bearing grease as the sledgehammer if the other doesn’t work.