Builds 75 Series cab on 80 series chassis with Cummins 6BT (1 Viewer)

[c2dfj45]

I started attempting to figure out how to mount the subtank. @c2dfj45 did a nice job on his so I’m using his thread as a guide.
I also need to figure out where the 3rd line on the filler neck goes.
View attachment 2486021View attachment 2486022View attachment 2486023View attachment 2486024View attachment 2486025

I think that 3rd line on my truck was T'd into the front tanks filler vent. We spent some time trying to figure that out and that is what made the most sense.

 

[Mr Cimarron]

I think that 3rd line on my truck was T'd into the front tanks filler vent. We spent some time trying to figure that out and that is what made the most sense.

Thanks!
I’ll have the same issue but opposite on the front tank. My 75 filler neck only has the three lines but the 79 front has three. I haven’t pulled the front tank back off the truck yet to compare the 75 and 79 front tanks side by side.

 

[coldtaco]

I started attempting to figure out how to mount the subtank. @c2dfj45 did a nice job on his so I’m using his thread as a guide.
I also need to figure out where the 3rd line on the filler neck goes.
View attachment 2486021View attachment 2486022View attachment 2486023View attachment 2486024View attachment 2486025

I don’t know which fuel line you are talking about but the vent originally goes into the frame, rubber hose to a hard line that has a 90degree bend into the frame, a grommet goes between the hole and the hard line to protect from chafing. The other two go around the filler hose, one has a one way air filter, guessing it allows air into the tank as the fuel is used? As to the third one don’t remember off the top of my head. If I remember I can try and look at mine again when I get home.

 

[Mr Cimarron]

I don’t know which fuel line you are talking about but the vent originally goes into the frame, rubber hose to a hard line that has a 90degree bend into the frame, a grommet goes between the hole and the hard line to protect from chafing. The other two go around the filler hose, one has a one way air filter, guessing it allows air into the tank as the fuel is used? As to the third one don’t remember off the top of my head. If I remember I can try and look at mine again when I get home.

A photo would be great but no hurry. I won’t start running hose for awhile.

 

[Mr Cimarron]

I did some fiddling today with both tanks. Still working getting rear tank mounts mocked up. At first I had the tank pushed to the left side because that’s how it sat with the filler neck attached. Then centered it which I like better. Is the stock 79 rear tank offset?

Then moved to attempting to swap out the original front tank with a new take off 79 tank. I pounded the sides like I did on the original to get it between the 80 frame. Then I ran into the same issue I had before. I can’t get it over the long rear output flange if the HF2A. I could dent the tank but I really don’t want to do that. Plus I wouldn’t be able to use the stock skid plate over it either. @bottombracket got us some 80 series part time cases coming that have the shorter output flange so I’ll wait for that. The HF2A will replace the split case in 80 so not a waste there.

Here’s old vs new. The only difference I noticed in the 75 vs 79 front tanks were how they vent.

 

[coldtaco]

Here are some pictures of my rear tank hoses

 

[Mr Cimarron]

Here are some pictures of my rear tank hoses

View attachment 2490704

View attachment 2490705

View attachment 2490706

View attachment 2490707

Thanks! Do you have three small lines coming from the filler neck? I defiantly don't have the second nipple on the tank in the last photo.

 

[coldtaco]

Does this answer your question?

 

[Mr Cimarron]

Still working on the sub tank mounting. Going really slow since the time change as I usually stop at dark.
I was able to fab up a crossmember to support the rear of the tank. It took two different bends. No tube bender so I just pie cut it and rewelded.

 

[Mr Cimarron]

Front mounts done. Would have been much easier to weld with bed off but I was lazy and didn’t want to raise it.

 

[Mr Cimarron]

Final work on the subtank mounts are done. Tomorrow I will clean it up a bit and paint. Glad to be done with it as it took me longer than expected.

 

[Mr Cimarron]

I got to working on the left floor pan the week. I have it half way welded in at the moment. Hoping to find some spare time this weekend to finish.
I have one kid needing help finding a car to replace the one I told him not to buy. The other one busted a sway bar link on his Civic by hitting a curb. Fun stuff. They are learning quite a bit helping me fix all the stuff they break.

 

[Mr Cimarron]

Both floor pans welded in and coated with Chassis Saver. Now need to get underneath and grind/paint the bottom.

 

[baroudeur73]

some news ?

 

[Mr Cimarron]

Not really. Just haven’t had time to dive back in. I’ve been having to fix a lot of the other vehicles at the house.

 

[ceylonfj40nut]

Not really. Just haven’t had time to dive back in. I’ve been having to fix a lot of the other vehicles at the house.

Old wise tail...

Cobbler has the worst shoes . Know that feeling all too well.

 

[dogfishlake]

I thought it was The cobbler's son wears no shoes?

 

[ceylonfj40nut]

I thought it was The cobbler's son wears no shoes?

Yea. Sounds better!

 

[Mr Cimarron]

I haven’t touched the truck in a while due to 80 getting love lately. However I did add something today. I swapped the notched balancer from the 80 to the 75. The 75 will get its signal from the balancer. On my 80 I get it from the flywheel.

 

[Dirty Koala]

I haven’t touched the truck in a while due to 80 getting love lately. However I did add something today. I swapped the notched balancer from the 80 to the 75. The 75 will get its signal from the balancer. On my 80 I get it from the flywheel.
View attachment 2634801

Is the 75 dash expecting a two pulse per rev signal or a 3 pulse per rev like the 80 guage needs to see?