C50 fuel tank
 

I bought a 1971 C50 grain truck that sat for 12 years and the fuel tank is full of crap. I have been running out of an fuel can and engine runs great. Has anyone replaced the behind the seat fuel tank? It looks like the same as tank in a C10 but there is no cross reference information. Any experiences or info will be greatly appreciated.

Re: C50 fuel tank
 

I am almost positive it's the same as a pickup truck. Being that your truck is a '71, it probably has the evaporative emission control. If it does, be sure to get the 'evap' type tank, not the '67-'69 style.

Re: C50 fuel tank
 

Thanks Bob, that is what I am thinking but I wish there was some way to verify.
I called about having the tank acid dipped and cleaned, the cheapest is $350.00 can buy a repop tank at LMC for $150.00.

Re: C50 fuel tank
 

I believe only 1/2 ton trucks got the evap tanks in 71/72, C20/30 did not - so am assuming a C50 didn't either - but it's worth asking when you order one just to be sure.

Re: C50 fuel tank
 

I bought a new tank, but that was before I read about cleaning the old one. So, if I had to do it again I would get some chain and vinegar and swirl it around in there and clean it out. I read a post on another forum where a guy strapped the tank on his tractor wheel, added gravel to the tank, and when he got back from plowing a field for an hour or so, the tank was like new on the inside. I thought that was funny.

Re: C50 fuel tank
 

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The guys in the Heavy Haulers Forum should know. I will move it there....

LockDoc

Re: C50 fuel tank
 

Funny you mention the tractor, I just watched that video on YouTube a bit ago, looks like it would work but I don’t have a tractor. Watched videos using muriatic acid (pool ph acid) and that worked super-fast and cut to the metal but comes with a lot of steps and the metal is stripped bare and will rust quickly. The problem with the vinegar is it takes a week, I have used that method on small engine tanks before, it really takes a while and you have to fill the tank completely with vinegar. Not sure yet which way to go.

Re: C50 fuel tank
 

I'm in the process of cleaning out the tank in my 67 c50 right now. According to Wes at Classic Heartbeat Parts, the tanks will interchange with the smaller trucks. 6 cylinders have 1/4" line and 8 cylinder has 3/8". My sending unit float was rusted out so I ordered a new one and some other parts from him.

A pressure washer got most of the crud off the tank floor and walls. I plan on using some pea gravel and muriatic acid to knock out the rest then use KBS coatings 3 step tank sealer. I had the first 2 steps from a previous project so figured I'd try it out.

https://www.kbs-coatings.com/tank-sealers.html

Re: C50 fuel tank
 

Ok, I looked at the block today, guess what...not a 307 as I was told, it’s a 350 #3970010.

Re: C50 fuel tank
 

I've cleaned 2 or 3 tanks with various degrees of success, none of them getting anywhere near as clean as a new one. The one I'm currently using has 3 fuel filters between it and the carb. If the repops fit, just buy one. If you do decide to try cleaning it I would recommend not using rocks or gravel. Use chain, nuts and bolts, anything metallic so you can get the last few out with a telescoping magnet if needed. The last 2 or 3 rocks can roll back and forth for hours before finding their way out. Ask me how I know this. :)