Hi all, I'm having A problem. I finished the installation of my 22 gallon Mustang tank again. I am satisfied with this version. So I started filling the tank, five gallons at A time, once A week or so. It's probably been 2 weeks since I dumped the the last 5 gallon can into it, totaling 15 gallons. I've been checking for leaks regularly and all has been well until A couple of days ago when I started smelling gas. There was none on the ground then, but last night there was. It was coming from the sending unit seal area. I siphoned out the gas and removed the sending unit. The seal popped out as I was removing the retaining ring. The seal has grown by about a quarter of an inch in diameter. It fit right in the groove when I installed it with A little petroleum jelly to hold it in place. I got all the gas at the Kroger gas station. What the heck? I found some square cut, chemical resistant o-rings at Mc master Carr, #228. Any one have A similar experience or any advice? Thanks Johnny.
I'll bet the bag of seals the manufacturer received from China had the wrong chemical composition. I toured an elastomer plant once and found these things are made in batches. The worker has a large tub containing plastic bottles of the different ingredients with an order sheet placed in the tub. The tubs are lined up on rollers and then each tub is processed individually. Some guy probably labeled a bag of seals incorrectly. Just my two cents. MD
Thanks Dude, That sounds like A real possibility. I've seen seals swell when exposed to the wrong chemical, but the seal came with the sender. I was surprised. So I drove over and bought the wrong seals. I measured poorly and got what I asked for. # 228 is slightly too small in diameter and slightly too large in cross section. I crawled under with my digital caliper tonight, and I will try again tomorrow. That seal shrank back to its original size sitting out on my bench today. I've never seen A swollen seal do that. I like learning new things.
I was under the impression that all gas is now "up to 10% ethanol". Is there A percentage where trouble starts ? I've been buying gas for my old mercury (1967) at that same Kroger for about A year now, and aside from vapor lock when the temps are up I haven't seen any problems. Now that you have me thinking about it, the vapor lock is A new thing this summer. Hmmm... So I took A"moment"to call my Kroger fuel center to ask about ethanol content of their fuel. She didn't know, but went out and looked at the pump and found no info. The store manager also didn't know, but offered to find out and call me back. I asked if there was A specific website area I could search. He gave me the cust svc number, they said to call the store manager. Now I wait. The suspense is brutal. Thanks modmav, that is something to consider.
it was just a thought the only things I run ethanol fuel in are the fuel injected the rest get premium, I do know some chemicals, alcohol etc. have unwanted effects on neoprene and rubber not sure about ethanol, drop a rubber gasket in paint thinner and it double in size
Not surprised by the lack of knowledge at a typical grocery store gas station. There are two different stories out there. One is that the tankers filling up at the distribution rack are pulling from the same tanks that Shell and Exxon are. The other story is that there is a minimum standard gasoline out there that goes the the off brand gas stations. Anyone have better info on that? MD
Sounds like you got a cheep Chinese seal. See if Spectra can supply you with the correct seal or buy their locking ring kit: http://www.ebay.com/itm/Fuel-Tank-Lock-Ring-Spectra-LO03/352024467838 Micah
The tank, sending unit, and seal are all spectra. The manager at Kroger called me as promised. Their gasoline is 9% ethanol in all grades. I use 93 octane. I've explored the chemical resistance of o ring materials, and the two I found that are resistant to both gasoline and ethanol are fluorosilicone and kalrez. I wonder what they use in flex fuel vehicles.
Yes, you found two good compounds for use with chemicals. Kalrez is a registered trademark of DuPont. It is actually a perfluoroelastomer. There are at least 8 versions of Kalrez with the most common being Kalrez 6375. This is often used in oil wells for seals in down hole equipment which is where I've used it. MD
I had the same problem with my 22 gallon Mustang tank/sender along with a lot of Mustang owners. They recommended this gasket. The one that came with the tank and sender wasn't even close to this dimensionally. Bought it, problem solved: http://www.cjponyparts.com/california-pony-cars-fuel-sending-unit-gasket-1965-1973-1979-1997/p/FSUG/
Thanks bmcdanial. Is that "Boatswain's Mate Chief Danial"? That gasket sounds like what I need. The other one is oddly tall and thin. Kind of like the shape of A rubber band.
Yep I believe you got a cheap china gasket, got mine from CJ pony but came with sending unit no issues
