DIY Network

1938 Packard: Clean and Rebuild Carburetor From "Classic Car Restoration" episode DCR-404

In this episode of Classic Car Restoration, host Mark Lambert addresses the fuel system on the 1938 Packard Club Coupe. The fuel system is often the most misdiagnosed and misunderstood system on any car. In reality, if taken component by component, it’s quite simple. In this third segment of episode 404, Lambert shows you how to both clean and rebuild your carburetor.

Note: This is a summary of steps included in the automotive restoration procedures shown in this episode of Classic Car Restoration. These are general guidelines for restoration procedures on this particular make and model of vehicle, and for the level of restoration selected for this project. There may be variations in procedures depending model, condition of vehicle, level of restoration undertaken and the types of replacement parts or upgrade kits selected. Always follow proper safety precautions, and read and follow manufacturer's guidelines, diagrams and safety notices that come with any replacement parts or kit that you select.

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Cleaning and Rebuilding Carburetor

Materials:

Washers
Gaskets
Wire brush
Carburetor Cleaner
Air hose

Figure A

Cleaning

• Disconnect your accelerator pump linkage and pull the cover off (figure A). Replace gaskets. To save a gasket you want to move laterally on it. (Using that motion instead of lifting straight off would save the gasket.)
  

  Figure B

• You will want to remove any gunk at the bottom of the carburetor (figure B) for it to work properly. Flip the carburetor over and check the main jet screws, that will give you access to the main jets. If you have a car that runs slowly on highway speeds but stumbles at higher speeds, these guys are plugged. Pull them off. Replace the tiny washers on each of these plugs or you will have a fuel drip and you’ll have to smell that all the time when you’re driving the car.

• Use a wire brush and carburetor cleaner to clean all your parts. Be sure to wear a mask suitable for chemicals. It’s important to dry these parts as well. An air hose makes this easy.

Replacement washers
Replacement float needle valve

Rebuilding

• Because our car is a Packard, there’s plenty of fresh parts available. Carburetor rebuild kits are available for many classic cars.

• Replace all the washers in the carburetor. We put a little drop of oil on ours before we thread them in. Always be careful when you’re threading these really tiny parts. Make sure you get the threads lined up before you put any kind of screwdriver on it. If you get them cross-threaded, you’re in trouble.
  

  Figure C

• Replace your float needle valve (figure C). When the needle is all the way down on its seat, and the float’s all the way up, it should be just below the lip, and that way there will be just enough fuel in the carburetor at all times.
  

  Figure D

• If your accelerator pump has a tear (figure D), like ours did, this may explain stumbling when you accelerate. The fuel isn’t going down the throat of the carburetor. Disassemble the old accelerator pump. Remove the felt, then the spring seat and tiny spring. The big recoil washer is then removed, the smaller one, and the recoil spring.

• Reassemble the small parts from above onto the new accelerator pump in the correct order: recoil spring, small washer, recoil retainer washer, tiny spring, another washer and the felt washer.
  

  Figure E

• Lubricate the pivot, tighten and then check to make sure it moves freely (figure E). Position the gasket, making sure the holes line up. Then, lubricate the leather diaphragm. The lip of the diaphragm must go down in to the cylinder without doubling back or you will end up with a mess.

• Before inserting the case screws, put a dot of oil on the tips and add the small washers. Tighten them and then go back and snug them up, working in a star pattern around the carburetor to ensure a good, tight seal.
  
  
  

  RESOURCES :
  
  
  Resources and Special Thanks for Classic Car Restoration 400 series
  
  
  The Packard Club
  Columbus, Ohio
  (National & regional clubs, car shows & judging, magazine, resources, etc.)
  The Cormorant magazine
  The Packard Club
  www.packardclub.org
  
  Packards International Motor Car Club
  (National owner's club, judging rules, magazine, newsletter and other resources)
  Santa Ana, CA
  Packardsinternational.com
  
  Packards of Chicagoland
  (Regional affiliate of The Packard Club)
  Elmhurst, IL
  Packards of Chicagoland
  
  America's Packard Museum
  Dayton, Ohio
  www.americaspackardmuseum.org
  
  The National Packard Museum
  Warren, OH (the birthplace of the Packard)
  www.warren.org
  
  The Packard Motor Car Foundation
  (Foundation for preserving the Packard marque) Restoring the Packard Proving Grounds and other Packard activities.
  www.packardmotorfdn.org
  
  Motorbooks International
  www.motorbooks.com
  
  Automobile Inspections LLC
  (Nationwide automobile appraisal & inspection services, including classic cars)
  Hartford, CT
  www.automobileinspections.com
  
  Classic Auto Appraisals (Evaluation of Classics, Street Rods, Antiques, Competition Cars, Exotics, Commercial Vehicles and Hand Crafted Vehicles).
  www.autoappraisals.com

  ALSO IN THIS EPISODE:
  	1938 Packard: Safety, Fuel Additives, Fuel System
  	1938 Packard: Fuel Pump Pressure and Volume Test, Removing Carburetor
  	1938 Packard: Clean and Rebuild Carburetor
  	1938 Packard: Carburetor Installation, Adjusting Idle Richness