Pick-Up and Sending Unit Repair Your Imperial's Gas Tank

 


Imperial Homepage -> Repair -> Fuel -> Gas Tank -> Pick-up & Sending Unit


Question from Charles (1931):

I am looking for a sending unit for a '31, I know that they make a universial unit but does not the old chryslers ground the unit in a different way. Also, cant send in to rebuild there is nothing left! So I am looking for a source or tell me the unversial will work somehow.

Replies:

From George:

You may want to try Andy Bernbaum's in Massachusetts...he has a lot of hard to find parts for old chryslers...I believe he's also on the web at www.oldmoparts.com.

From Sherwood:

Try this phone number 508-792-9500 Atwater Kent

From Paul:

Isn't that car 6 volt with positive ground? I think that was common, so I don't know why a universal part specifically wouldn't work. Just a thought...

From Kerry:

If Charles is looking for a 6V sending unit, good luck! I never found one for my 54. Ended up adapting a VW unit that worked well enough for me to never run out of gas.


Question from Tony (1959):

Just got the sending unit out of my tank and, lo and behold, someone put in a CORK!!! I read that NAPA and Ford have the correct brass float. Please, could someone supply me with a part number, or other identifying reference?

Reply from Steve:

Ford part number COAZ-9202-B


Question from Aubrey (1961):

My '61 seems to have developed a leak at the front top of the gas tank where the sending unit is. This became evident when I parked her on an incline where the gas was forced to the front of the tank. Before I start any repair on this I would like to make sure I've got the right parts. Is there a gasket where this unit goes into the tank. If so, are they readily available out there or should I be prepared to cut one myself?

Also, while under there I found that the sending unit wire was not attached anywhere (could be a good reason the gas gauge wasn't working) There is no wire anywhere nearby so I assume somebody in the past has removed it for some reason. Can anybody tell me where this wire would usually come through so I can try to locate the other end and get it hooked up again?

Replies:

 From John:

The sending unit wire comes down through the trunk floor. It is blue in color. You shouldn't have any problem locating the seal.

From Hutch:

There is a gasket that goes there and it is still available from Chrysler dealers. I bought one just today for my '65. My tank leaked there also. There is a metal strip approx. 3" long, with a "Clip" on each end that clamps over a short rubber section of the fuel line to establish continuity from the sending unit to the steel fuel line. I paid $1.37 for the gasket.


Question from Bob (1963):

My '63 runs fine until the fuel gets below 1/2 tank.... then if it is going uphill it sputters and kicks like it is running out of fuel and goes about 20 MPH top speed, but it doesn't stall. Once it gets to the top of the hill and levels out, it catches itself and runs fine again. I guess its a good thing I don't have very long hills in Atlanta!

Sitting in the garage, level, it starts and runs fine at all levels of fuel capacity, even at 1/8 tank.

The fuel coming into the carb seems clean and the fuel filter is clean, even after a few thousand miles.

I siphoned some fuel out of the bottom of the tanks and poured it through a cloth filter and it looks clean with not obvious dirt particles.

My theory is that the fuel pickup tube inside the gas tank may have a perforation(s) in it, around the 1/2 tank level, and when I step on the gas going uphill at that level of fuel, and need more fuel pumped into the carb, it starts to suck air, and the engine gets just enough fuel to keep the car running, but not able to go uphill without rebelling.

Any other ideas or any experiences with a similar problem?

If this is the problem....

Can I get the line out of the tank without dropping the tank, or should I bite the bullet, drop the tank, and it cleaned and resealed, and fix the line as well.... and maybe evening replace all the fuel lines while I'm at it?

Where can I get a replacement for this fuel pickup line?

Reply from Phil:

I had exactly the same problem with a lesser Mopar...I found a huge blob of water in the fuel tank. Regardless of the source of your performance problem, it would do no harm to drop the tank, flush it and thoroughly dry it...no telling what you'll find inside it.


Question from David (1963):

Am I right or am I wrong but my car has electroluminescent dash lights (63) I have been told that you should not ground the sender wire to see if the gauge works is this correct or not and if so how does one check these gauges, I put in a "new" sender unit which briefly gave a 3/4 reading before slowly dying as did the previous gauge?

Replies:

From Rick:

Grounding the sensor wire can burn out the gague...I learned this the hard way on my '61. Put a dash light bulb in the circut or a matching sending unit.

From Mark:

Just don't cross the wires. Sounds like I'm in the Ghost Busters Movie. "Don't cross the streams!". On non-circuit board cars like '63, the voltage regulator is in the one of the instruments. Trying to remember which one ; Either the temp or fuel. It will have an extra prong on the back of the gauge. Note, all white wires with red connectors are high voltage on your cluster. Don't mix those up with other wires! Anyway, the guages work pretty much the same as later models except that they're not mounted to a circuit board in '63 (and earlier) models. The method for checking them are all pretty much the same. Just watch out for the high voltage lines on 61-63 models!


Question from Jan (1965):

Does someone have a tank sending unit for a 1965 Imperial? All my instruments are now working, but I need the tank sending unit.

Reply from Rick:

I had the sending unit for my 65 rebuilt; if that is an option you might consider it. It was done at Instrument Services Inc. 11765 Main St. Roscoe, IL 61073. 815-623-2993 Toll free 800-558-2674.


Question from Leo (1967):

I took the fuel pickup out of my '67 gas tank to repair a broken connection. The sock filter looks pretty wretched. Someone on the list suggested that a Ford filter is a good replacement. What year, model, part number filter should I order?

Replies:

From Steve:

Your friendly neighborhood Chrysler dealer probably has one sitting on the shelf. They were the same for years and years.

From Brian:

Check with your local mopar dealer, they have several different sizes, one should fit yours.


Question from KT (1968):

I'm getting ready to drop the tank on my '68 Crown. It definitely needs to be boiled out. So I'll be needing both a new filler neck "O" ring and a new sending unit gasket.

Would somebody be so kind as to direct me to a known source for these items, or at least provide me with parts numbers so I can search for them myself?

Reply from Ron:

I still get mine from the local Dodge/ Chrysler dealer here in Phoenix. I might also recommend you change the nylon sock filter at the end of the pick up tube. If you have problems, this dealer will ship to you.


Question from Bruce (1969):

I'm looking for fuel tank sending unit/intake pipe for a '69 Coupe.

In lieu of paying $140 to have my fuel tank sending unit rebuilt, I thought I would take a whack at it. Inside is a simple rheostat wound around a flat piece of insulator. This little structure appears to be insultated from the metal chassis of the sending unit. When disassembled, there is full continuity between the wires of the rheostat winding and the contact screw which attaches at the outside of the senidng unit to the gas guage lead. Is this right? I thought that a varying resistance in this circuit what what the gas guage was measuring? Any helpful hints?

Replies:

From Elijah:

You need part # 2932 965. Call your local Chrysler dealer and give them this number, and there's a *slight* chance they may be able to order it for you.

From Pete:

There should be 0 ohms resistance between the stud outside the sending unit and the "close" end of the resistance wire. There should be about 80 ohms (I think) resistance between the stud and the "far" end of the resistance wire WHEN THE FLOAT IS IN THE TANK EMPTY POSITION.

The circuit is simply a loop from the stud, through the resistor, to ground (the fuel outlet pipe). The float position determines how much of the resistance wire is bypassed when current flows through the float arm wiper.

From Dick:

Peter is on the money here, as usual. I would add that the resistance should drop to around 10 Ohms when the float arm is in the tank full position.

If you look carefully at what moves as the float arm swings, you'll see a tiny brass contact which slides along the wires of the rheostat, this moving contact point brings more and more wire length into the circuit as the float arm drops, thus raising the resistance to the 70-80 Ohm range. These values are NOT critical - if you have this sort of resistance variation, anywhere in the ballpark of these number (say within 30%), the fuel gauge should work pretty well..

If the sender is doing all this, your problem is probably elsewhere. Try grounding the wire at the sender terminal (momentarily, don't leave it grounded as this is a little hard on the dash indicator). Now see where the indicator goes - it should go to full tank and even beyond. If it does, there is nothing wrong with the dash unit or the wiring, and your problem may be a poorly grounded tank (if there is no grounding wire, add one), or it is possible your float is not floating, thus the tank always reads empty. If this is your problem, drain the gas out of it and resolder it. You can expel the gas from it by heating it in hot water, with the hole above water so you can see the gas come out.

Follow-up questions from Bruce:

My sending unit is out of the tank, and I have opened the rheostat housing and confirmed that the brass tab, spring-loaded armature, and the rheostat wiring all appear intact. I bent the brass very slightly outward so that I could hear it scrape across the rheostat. However, the resistance I am able to measure goes from 0 ohms to about 10 ohms. This doesn't sound like it's within your parameters. Any ideas?

Reply from Dick:

Seems to me that your ohmmeter is telling you lies. If the total resistance unit is being inserted into the circuit when the float is at the empty position, the resistance should be about ten times what you are measuring. If you can get access to a known resistance to measure in order to test your ohmmeter, I'd say that is a good thing to do!

Bruce's Fix:

Dick was right, what a shock, ohm meter was bad, sending unit good. BTW, this is after I soaked the sending unit in Evapo-rust for several hours. It seems to be a very good and very non-toxic product. It took off a lot of rust.


Question from Kevin (1971):

Where is the fuel sending unit at? When I fill up my tank it says I only have a 3/4 of a tank, so I have to do somthing to the sending unit. Any suggestions?

Replies:

From Michael:

Before repairing or replacing the tank sending unit, clean and tighten all the connections in the circuit. Any iffy connections can introduce enough resistance into the circuit to change the calibration. The most likely connections to be cruddy are the one at the tank sender or the connector plug(s) in the wiring to the rear of the car.

From Kerry:

If you disconnect the lead from the fuel tank and ground it while the key is on, your guage should read full. If it doesn't, your guage is bad. If it does, your sending unit has a problem. I use a couple long jumper wires with alligator clips on the ends and go directly from the battery ground. That way I can hook up to the battery ground, the sending unit lead and touch them together while I'm in the car so I can see the guage. Othersize it takes two people.

From Don:

The sending unit should be at the front of the tank on the upper half, usually the ground strap starts rusting which creates a bad conection. Ground straps are available, but one can be made with wire, but the main solution is having a good clean conection on the ground. This usually takes care of the problem ,but there are times when you need to get a new sending unit.

From Dick:

I would add to Kerry's excellent suggestion a warning - don't leave the sender wire grounded for more than a few seconds, as you are running excessive current through the dash indicator. A few seconds won't hurt it, but be sure to limit it to that. Michaels suggestion of cleaning the wire connections is also a very good idea.

This page last updated August 22, 2004.  Send us your feedback, and come join the Imperial Mailing List - Online Car Club