Imperial Homepage -> Repair -> Fuel -> Carburetor -> Cleaning
Question from Dan:
Does anyone know of a really good (read: STRONG) cleaner for carburetors??
"Gunk" brand makes a decent cleaner that comes in a gallon bucket with a wire strainer. I've found it at Advance, AutoZone, and other major chains for about $10. It's worked pretty well on carburetors I've done recently.
If that's not strong enough for you, NAPA has a 5 gallon can of stuff that will take "hair, hide, and all!" as my dear old Granddad used to say. It's MUCH stronger than the Gunk stuff, but it's also about four times the price.
As Elijah mentioned the stuff from Napa in the five gallon bucket is really the way to go, but it is almost half the price of a new carburetor! The five gallon bucket allows you to fully soak the complete carburetor body and comes in handy for deep cleaning all sorts of other parts, but in the end you are left with five gallons of very nasty, smelly stuff! The Gunk cleaner in the gallon can works ok, the only problem is that a full size 4-barrell carburetor body won't fit in the can! I got around that by cutting off the top of a rectangular gallon lacquer thinner can. I slipped my stripped AFB body in the can and poured the cleaner over it. After several hours, I pulled the body out and turned it over so the part sticking out of the cleaner would get equal time. I rinsed the body with lacquer thinner and it came out dry and grease free with the exception of some dry mineral mud (plain dirt) still in the pores of the aluminum. Stage two cleaning was in the pots and pans cycle of the dishwasher followed by thoroughly blowing out all the passages with air, which got it as clean as it needed to be.
Try soaking the carburetor in Pine Sol. Don't laugh, it actually does a good job of dissolving the gum from old gas. It is also much cheaper then carburetor cleaner and doesn't eat plastic or rubber parts. A friend of mine has used Pine Sol successfully for years, in his business, to clean lawn mower carburetors and has saved himself a small fortune on carburetor cleaner.
Lacquer thinner has always worked for me, be it has safety concerns so read the label.
Question from Bill (1959):
I have decided to take on the task of repairing my accelerator pump in the carburetor of my 1959 Imperial. Do I need to have a specific carburetor model which this kit will work for? Are they available at a local car parts store? All I know is I have a Carter Carburetor which is no longer in production. I figure if I took apart a lawn mower engine as a kid and put it together again and got it running, with my years of wisdom, I should be able to tackle this project.
Take the number off the tag on the carb or just take the tag and take it to almost any auto parts store and they should be able to order the kit for you
Your carburetor is a WCFB (William Carter Four Barrel) OR an AFB (Aluminum Four Barrel) I'd bet on the AFB. AFB kits are readily available at any decent parts house. I just got one a few weeks ago for my 66 300. WCFB kits are a little harder to find but still can be ordered locally if not in stock.
If your car has the OEM carburetor it is a Carter AFB # 2927S (check the # stamped on left front mounting flange). Give the number to the counterman at any well stocked auto parts store and he'll likely have a kit on the shelf.
Question from Bill (1959):
Well, I got my carburetor rebuild kit, and am ready to go to work on it. I've got all four bolts off the carburetor and am ready to lift it out, but have a snag with the metal fuel line which attaches at the rear. When I go to unloosen the bolt holding it to the carburetor, the pipe begins to twist. I tried to unloosen the smaller fitting which goes into the larger one, but got the same results. Then I thought about leaving it on the carburetor and removing the line where it meets the fuel filter, but don't know if I will be able to get it out through the tangle of wires from the distributor, and the hoses in that area. Any suggestions on this one would be appreciated. I wanted to start working on it tonight, but I got a late start, and it got dark before I could figure out a remedy to my problem.
If it's a bango fittings you might be able to use a small vice grip or robo grip on the fitting and a wrench on the bolt.
You're going to need 2 wrenches. Loosen the little one from the big one first, because where they are tightened together is what is gripping the fuel line. You'll have to hold the big fitting securely somehow, to get the little part that screws into the big fitting loose. If you only turn the big fitting, it'll just twist and ruin the fuel line. Always a good idea to give it a sharp whack with a small brass hammer and a drift to help loosen things before applying leverage.
Don't try to take if off with the fuel line attached.
The way to get the line off is: hold the larger nut with a 3/4 inch wrench while you loosen the smaller fuel line fitting. This is always the rule when working with line fittings. The purpose of holding the larger nut is to prevent any twisting of the line being disconnected. You'll find that once you get the two wrenches on there, with their two handles about 30 degrees apart (the smaller wrench 30 degrees clockwise from the larger wrench), you can just squeeze the two handles together with one hand - it will be hard to start the nut moving at first, then it will release and spin off easily with your fingers. The reason for doing this with one hand is that then you can be certain not to be putting any rotation force on the line or the carburetor fitting, all the force is between the two nuts you are trying to separate.
Hold the brass inlet fitting at the carburetor with one wrench and loosen the fitting on the line using a flare nut wrench (or carefully with a Crescent wrench). Leave the carburetor bolted down snug when you do this. Take care that you don't round off the flare nut -- if it's shot already grab your vice grip or channel lock pliers and have at it. If the connection is stubborn keep working with it on the car. It is possible to leave the line on the carburetor and remove the carburetor and line together with some gymnastics (done it but easier off than back on so this approach is much more of a pain than getting the right tools).
Follow-up and Question from Bill (1959):
Thanks all for your helpful advice on removing the fuel line from my carburetor. Using the two wrench method and squeezing them together with my hand, finally broke the screw fitting loose. The carburetor is now redone and cleaned up like new, and sitting on my kitchen counter waiting to go back into the car. The floats looked good, and the good news is my choke is working, so hopefully replacing the accelerator pump will do the trick. Kerry P. was right on, the '59 Imperial uses the Carter AFB. Do I need to do anything after putting it back on like priming it with gas?
Just in passing, getting rebuild kits for these old things is not that difficult. Although I ended up buying a spare carb for my 58, I am still using the original, miniscule, non leaking, crack at the foot mounting notwithstanding. I counsel you to be careful with float adjustments. Following the spec. sheet is not always wise. Kerry Pinkerton has an old mechanic's trick for a certain era of carburetor, and my own is adjusted to suit the car rather than the book. It was not rebuilt by me, as I consider the Carter AFB to be pretty much near the top of the food chain and beyond my capabilities. I have worked other, more ancient carburetors, like a Model A's, for example.
You will probably have satisfactory operation right off, but you can improve your idle smoothness a little by adjusting the two idle mixture screws, 1/4 of a turn at a time, after the engine is thoroughly warmed up and is idling at a normal curb idle speed. Back each screw out until you just begin to notice the idle speed dropping off (you can hear the very slight change in tone from the engine), then run it back in about 1/4 to 1/2 half turn, searching for the fastest smooth idle. Repeat with the other side's screw, then double check each of them. Now you should have a very smooth idle, and you may be able to adjust the idle speed screw now to save yourself some gas and still have a good idle.
Was the choke working OK before? I thought we had pretty well determined that the choke was not functioning, or else the choke pull off wasn't working. Did you find the trouble? I hope so, because if not we are still in the dark as to why you were having problems driving it when it was cold. If the accelerator pump were bad, it would have affected the driving under all temperatures, any time you were trying to begin an acceleration.
All the required adjustments are described in the directions that come with the kit, both how to make them and what the settings are. Also, there are measuring rulers to use in setting the float adjustments. Normally, a rebuild such as you have done would include checking all the adjustments. However, unless something has happened to bend something, if they were set close to right before, they should still be OK.
The leather cup on the accelerator pump plunger is formed to be the right size when it is assembled to the pump shaft. As these age, particularly if the car has gone unused for a long period of time, these tend to shrink and the pump doesn't work as well as it did when new. Often, this is the only thing that is wrong with a balky carburetor.
If the choke is closed when the engine is cold, and opens partly as soon as the engine starts, and then further opens as it warms up, the choke is working right. Its operation has nothing to do with throttle position, except that since the spring that positions it is rather weak, really high throttle openings let so much air blow past it that it tends to open a little. This is not normal driving, however, as one would not normally race a cold engine.
The spring loaded thingies that jump out of their little holes in the top of the carburetor are the metering rods - they are what controls the mixture richness for acceleration etc. The directions with the kits describe, picture, and name all these things, and tell you what order they go back together in. It is very important that you put everything back in the right place - if you feel you might have missed some small item, or put it in the wrong place, I think you should spend some time with the directions and diagrams and then take the carburetor apart again to double-check your work.
Of course it won't hurt anything to just put it on and try it, trusting to luck, but these are complicated devices, and you might cost yourself extra work by doing it that way.
Question from Kevin (1971):
I have decided to re-build my carb instead of having someone else do it. Is there any special tools I need? Is the re-buld car kit in summit mag for the carter (CRT-902317A) the right re-build kit?
Do you recomend that Ido it myself? How long should it take me? What other supplies do I need?
It is pretty straight forward. Just take your time and if something is not clear then do not proceed until you have figured it out. Don't assume anything is correct as when the carb is back together and if it is not running properly these little unknowns will come back to haunt you.I hate
doing things twice.You will need some carb cleaner(kleenflo or equivalent) which is reusable and very strong stuff. But it does the job. It also stinks so be prepared. You should also buy yourself a Carter carb manual from your local auto shop or book retailer. I have one which is pretty good but I don't have it handy to quote the name and author. The more info you have the better off you are.Tear the carb down on a clean organised work space. Make notes where you feel applicable. Even pictures.Soak all metal parts in carb cleaner as per carb cleaner instructions.Then you will have to rinse with solvent and let dry on clean workspace.Check as best you can the new carb kit with original pieces before breaking seal on kit in case you have to return it.Lay out all new parts and identify them all. You will invariablly
have more parts than required as these kits tend to service more than one model.So be very careful about parts id. Set extras aside.Don't throw any old parts away until the car is running properly again.You will need a few good screwdrivers, good lights at work bench,flashlight, good pliers assortment(needlenose, slip joint, etc)a toothbrush to scrub small parts with,carb cleaner in aerosol can to blow passages clean(or compressed air source)eye protection, heavy synthetic gloves to protect hands from carb cleaner, some stiff wire(lockwire works good) to clean passages with, a six inch rule or similar and a few other things I have forgotten. Maybe some crocus cloth or fine emery cloth.And maybe some new fuel line and vacuum lines while you are at it.Should also have a vacuum gauge for checking leaks when you reinstall carb on engine. Before reassembling carb clean "all" passages with carb cleaner aerosol or compressed air. If they are plugged you can use wire to try and poke through at first and then clean with carb cleaner. Preparation is everything with this job as is cleaning and setting everything up to specs.If you do it right you will be quite satisfied. If you do it wrong it will be a major headache.
Find a NAPA parts store in your area, I have nothing but praise for their kits-always the proper one. Make sure you give them the Carb. number either off the tag attached to one of the housing body screws, or a stamped number in same.
Rebuilding a carburetor is not for a novice. Even professional rebuilders will tell you that a carb rebuild is an "iffy" proposition. Sometimes it's even better to buy a used carb in working condition than invest in a rebuild. If you do decide to rebuild your own unit, pay lots of attention to detail and try to remain in contact with an experienced carb rebuilder for questions and problems that might arise.
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