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By brettnelson - 9 Years Ago
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Hi, I recently bought a Cardone part # 30-2808 distributor for 1957 and later block. I hooked a vacuum hose to the advance diaphragm to check
operation before installing. (I'm replacing my 1955 load-a-metic distributor). The advance arm from vacuum can would not move even though the advance
plate in the distributor is free. I provided as much suction as possible using my mouth. I removed the diaphragm from distributor and again tried to actuate the arm while sucking on the vacuum hose. I couldn't get it to budge. Its seems as if there is a very tight spring under the diaphragm and it takes a huge amount of
pressure to overcome. Does this distributor require some centrifugal advance to kick in before the vacuum will pull the diaphragm / arm ?? Anybody with experience with this distributor care to chime in? Thanks in advance, Brett
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By brettnelson - 9 Years Ago
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Motorcraft part # 12127
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By GREENBIRD56 - 9 Years Ago
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Many of the vacuum pots are adjustable - it takes a 3/32 Allen wrench - that is long enough to reach down directly through the vacuum port. To limit the amount of vacuum advance on those units, you turn the Allen screw inside to preload the diaphragm spring. It could be - that your unit has the preload set-up pretty tight already - and therefore takes a good bit of vacuum to make it move the arm. The direction the screw is turned to tighten it - is not the intuitive direction. You must turn them CCW (counter-clockwise) to increase the spring loading.
Can you run the engine as it sits now? And then use the existing manifold vacuum as a test source? I have a '74 Olds I use as a vacuum donor when testing the pots......................
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By miker - 9 Years Ago
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Those Mity Vacs are only $40 or less on Amazon. Put a vacuum gauge in the car, check your vacuum at cruise. You can then duplicate rpm and vacuum at the dizzy, and check your total running advance. With a second set of hands and eyes, you can plot the vacuum curve by inches. Really helps when tuning. Bleeds brakes real well, too.
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By Talkwrench - 9 Years Ago
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It should move when you suck on it, try Steve's suggestion see if it has an adjustment. While you have it in your hand maybe you want to modify it so you shorten your timing a bit and also you could try fit Mr Gasket D925 springs as well...? Jus' sayin'..
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By brettnelson - 9 Years Ago
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this is great to know, unfortunately i can feel no adjustment screw inside vac can...... And the motor is not running/no vacuum source.
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By brettnelson - 9 Years Ago
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I got out my handheld vac gauge and found that i can pull 12-15 inches with mouth vacuum, this does not seem to be enough to move arm in vac can.......
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By Ted - 9 Years Ago
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If your current vacuum chamber does not have a detachable vacuum hose end, I'll suggest another vacuum can. If you do have a vacuum can that you can take apart, then remove the inner spring and related spacers and see if it was put together incorrectly.
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By brettnelson - 9 Years Ago
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yes Ted, I agree. It is not removable. I guess i'll source another can. Probably a lot easier than trying to return complete distributor to Advanced Auto and have them send another one........
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By brettnelson - 9 Years Ago
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good news ! Like greenbird suggested, my vacuum can IS adjustable. I had to use a punch to open up the hose nipple up to be able to fit a 1/8 allen wrench. Turned it counterclockwise and was able to relieve some of the spring tension. I can now advance plate with mouth vacuum as long as I give the arm a little nudge/help with a screwdriver. Its a start  I'll be interested to see how the Edelbrock pulls on it ...........
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By brettnelson - 9 Years Ago
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 I fou
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By brettnelson - 9 Years Ago
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I found an adjustable can from RockAuto.com and it's a night and day difference than the one that came on the Cardone distributor. I adjusted the Cardone to its loosest setting and could barely get the arm to move. I could move it with finger but it was still very tight and crunchy feeling. The new Standard part #VC221 takes little vacuum to move and it is adjustable and smooth.
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By GREENBIRD56 - 9 Years Ago
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Glad you got the cans work for you - interesting that there must be more than one socket screw size in them. Now that you have the equipment - beware that the can is "active" at part throttle cruise - so long as the engine is producing vacuum - the can is adding advance.
This chart comes in some of the replacement can boxes - gives you some indication of what you have to work with. By using a "live" vacuum port off your engine (and a vacuum gage) - at idle - you can test different settings by taking a look at a timing tape on the damper. Simply by pulling the hose on and off the nipple you should see the result at .....say 15 inches Hg. (idle). Those who drive (or have driven) with a vacuum gage to monitor fuel economy will vouch for the amount of vacuum you can see while traveling at road speed.
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By brettnelson - 9 Years Ago
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Thanks for the good info Steve ! , as it turns out the new vac can is going to need some mods since the arm has a different angle than the original, looks like I
will have to relieve the distributor housing slot a little and bend the arm...... Brett
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By BamaBob - 9 Years Ago
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The vacuum advance made for the 1957 FEK 12131-B distributor, the inlet end does have a removable end and inner workings. These advances can be bought new, however, they do not come with the removable parts. I have one that does not have the missing parts and have been looking for them with no luck so far. Can anyone tell me where they can be purchased? It does not make much sense for them to be sold new with missing integral parts and there not be a readily available source for them. Any help here would be appreciated.
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By 2721955meteor - 9 Years Ago
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if the vac can has a straight arm,it is incorrect. should have some fancy bends,also your carb won't match the list. you can modify it re a post on how to do this,or get a 57 carb. I would tend to return the whole thing if it came with the vacume unit.. or did you install the vacuum unit.
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