C2 gas tank sending unit
Is it difficult to remove a tank sending unit? Anything to watch out for when removing or replacing? I do not want to remove the tank from the car. Are replacement sending units available from GM? GM part number? Thanks much for any information / suggestions.
-
-
Re: C2 gas tank sending unit
Richard-----
No, it's not too difficult. However, having the special tool designed to rotate the cam-lock retainer can be a huge aid. Otherwise, it's a lot more difficult, especially with the tank in the car. The tool is available from Kent-Moore or, at least, was the last time I checked. It's Kent-Moore #J-22554.
The sending unit is still available from GM under GM #6428065. However, it GM lists for about 450 bucks. Aftermarket replacements are also available at considerably lower prices but problems have been reported with these. I'd "bite the bullet" and go with the GM piece.In Appreciation of John Hinckley -
Re: C2 gas tank sending unit
Thank you Joe. Is there an "O-ring" I should expect to replace also? GM part number?Comment
-
Re: C2 gas tank sending unit
Hi Richard:
Due to the way the sender is constructed, it is difficult to fully drain the tank by simply disconnecting the hose from the sender. Typically, an inch or so of gas will still be in the tank when the sender outlet stops flowing.
So, be careful that you don't get an unexpected cascade of gas when you remove the sender. Sometimes siphoning can get most of the gas out, and you can tilt the car to one side to force the remaining gas to one end of the tank.Comment
-
Re: C2 gas tank sending unit
If you can wait a couple of months GM/AC Delco/Delphi will be selling a new improved unit from CHINA at a much, much lower price.Comment
-
Re: C2 gas tank sending unit
Joe L., Joe R, & Ken;
Thank you very much for the good advice, this is exactly the type of information I was looking for. This is very helpful.
Ken, any idea where I should watch for information on availability of the "new" sender should I decide to go that route? I expect most Corvette parts dealers will eventually handle it. Could a person get the availability information from GM somehow?
Thanks again.Comment
-
Re: C2 gas tank sending unit
Richard,
Pump as much gas as you can from the tank and raise the passenger side of the car. Any remaining gas will be away from the sending unit opening.
My experience with a new sending unit was not good. Couldn't get it to read. You might be better off finding a good used original.
While I had all the gas out of the tank, I also cleaned it with cleaning tool I fabricated and some lacquer thinner. It worked great.
Good luckComment
-
Re: C2 gas tank sending unit
Douglas,
My tank needs cleaning also, not rusty but "gummy" with old gas. I will try your suggestion. I have not removed my sending unit as yet, I will try to make it work (clean it) before I look at purchasing another.
Thank you.Comment
-
Re: C2 gas tank sending unit
There are a variety of replacement senders on the market, with significant visual differences that indicate they are made by different companies. Some of them have very unusual looking resistor elements. I don't know which versions are causing all the reported problems.
A couple years ago John Hinckley had an article in Corvette Enthusiast about troubleshooting C2 senders and gauges. Included in the article was a photo of a reproduction sender sold by Corvette Central. I noticed that it closely duplicates the original design, although it lacks some of the Delco markings. If I had to purchase a non-GM sender quickly, I would be tempted to by that one, just because it appears to duplicate the original design.Comment
-
Re: C2 gas tank sending unit
Service replacement units with what appears to be the correct Delco logo has it rotated 180 degrees.
= 1 point deduction.
HaNDComment
-
Re: C2 gas tank sending unit
Thanks much Joe & Mike.Comment
-
Re: C2 gas tank sending unit
Hi Mike:
I agree with you that it appears that factory installed senders had some differences from some of the GM service replacements of the same part number. According to my research, one difference is the orientation of the AC stamp (typically as shown in the "version 2" photo below). Other differences include the use of a black float and a black sock on factory installed units.
However, there does not appear to be a consensus that ALL factory senders had the logo oriented like the "version 2" photo. I posted the two photos below on the tech board about a year ago, and no one seemed 100% sure about the orientation of the logo. I don't think the NCRS knows enough to justify making a deduction based on the orientation of the logo.
By the way, I have two NOS service replacement senders, and one has the logo right side up while the other has it upside down. So, not even all service replacements were identical.Comment
-
Re: C2 gas tank sending unit
Richard;
Taking the sender out is not that hard to do... I just did it (again) recently. Siphon the tank to the very bottom. What gas is left will sit in the low spots in the tank and will not be a problem. When you remove the gas line you will get a few ounces of fuel,not more than that.
Get the removal tool as Joe has recommended.. it does make it easy. When you get a replacement you will find that the repro houses typically carry two; a domestic and an import model. Buy the domestic and it will be less expensive than genuine GM. My replacement is one of these and works just fine.
Good luck!
JoelComment
-
Re: C2 gas tank sending unit
Hi Joe.
Thank for the posting of those great shots.
Agreed, Version 2 is what we typically see on original cars.
I know you fully understand how the Judging system works, but, just in case anyone is looking in who may be curious...
It seems during nearly every Judging meet the term "You haven't seen every car" pops up. True, and without the benefit of specific factory records, empirical data has been assembled over the years from the large population of known original examples and documented to establish a fairly conclusive standard to support these positions.
I further suspect these units and many other parts had a multitude of applications. It would then be possible that the "Version 2" was part of an original production overrun and the other produced post-production as a service replacement, with both travelling over the counter.
HaNDComment
Comment