who rebuilds fuel pumps 40083
Hi guy's should i try to do this myself or have someone do it that has done them before, the valves look good but the round diaphram part is so dry it wont give at all, i amagine from sitting , would you change the valves if they look good or just the diaphram part.also does anyone sell the correct rebuild kit with the yellow tiger stripe bottom gasket.
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JR -
Re: who rebuilds fuel pumps 40083
Jim,
Talk to Hal over at this joint:
First, if you are looking for a diaphragm and pulsator cover gasket made from cotton reinforced neoprene like original..........forget it. All new rubber components are made to tolerate methanol laced gasoline, and so are made of nitrile rubber (buna-n). Much, much better than original, and will last forever............but, the reinforcement is not cotton.........probably nylon or similar which does not stand out like the cotton. It is noticeably thinner, and some kits include the mandatory tiger stripes in red instead of correct yellow, so any trusty judge suffering from acute OCD will spot it faster than you can polish the heating element on your Casco cigar lighter.
Be advised that it is tricky rebuilding your own, particularly if you intend to dismount the old diaphragm and mount the new diaphragm on the original plunger rod, as is required with this particular kit. This outfit will dismount/remount the new diaphragm if you sent it to them. It is CRITICAL, that the dimension from the plane of the diaphragm to the bottom of the plunger slot be EXACTLY AS ORIGINAL, otherwise your pump pressure will not be within the proper range of about 5-7 psi. If you shim the diaphragm spring, this will have the same effect as changing the above dimension, which you don't want to do.
If your pump still has its original link retainer pin, it CAN be removed and reused without destroying it...............new pins are different than originals, and are NOT AVAILABLE ANYWHERE. If this is done correctly, a new retainer washer can easily be made, to match the original one.
The poppet valves are easily replaced and MUST be done. Be sure to use Form a Gasket sealant under the seals, and be very careful not to deform them when driving them in place. Be sure that they are FIRMLY and evenly seated against the gaskets, and properly staked, otherwise they will leak. If this occurs, the car will run fine during normal driving, except that it will suffer from fuel starvation in the upper rev range............not easily noticed by most NCRS types. My old pump had a DISLODGED outlet poppet valve, which was rattling around within the pump!!! It delivered an unsteady 3 psi at idle, but began to starve the engine at higher revs.
The upper (pump) housing is cast out of magnesium on the 6440083 pump, which is why it is so rare and expensive. If you decide to wash it using a mild acid, such as muriatic, be aware that it will turn black. This is rather attractive, in its own right, and will prevent the fuzzy, whitish oxidation which soon occurs with magnesium. The judges will probably suffer dyspepsia if they see it, although I like it!
Finally, there is a tricky procedure..........difficult to explain..............involved in removing the link from the plunger rod once you have removed the pivot pin. If you are reasonably dexterous, and have not drunk too much coffee (or booze), then you will acquire the skill.......eventually.
There are other vendors who sell the kits complete with NEW plunger rod/diaphragm pre-assembled....................but I cannot say whether or not the rod is as well case hardened as the original; that is the reason why I use this particular kit. The major wear point of the rod, is at the slot, where it contacts the arm. Original plunger rods generally suffer ZERO wear at this critical point.
Have fun.Last edited by Joe C.; February 13, 2009, 11:54 PM. -
Re: who rebuilds fuel pumps 40083
Nice work, Joe.
Great pics.
HaNDComment
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Re: who rebuilds fuel pumps 40083
Before /after:
The last photo shows how critical an exact slot to diaphragm dimension can be.
This was later tweaked so as to provide 7 psi.Comment
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Re: who rebuilds fuel pumps 40083
Now my original 64 pump had the yellow not red
" mandatory tiger stripes (red, not yellow)" SOoo, did that color change for 65 with 63 being yellow OR . ?Comment
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Re: who rebuilds fuel pumps 40083
I have edited the original post, to clarify. This particular kit uses nylon reinforced nitrile rubber diaphragm and pulsator cover gasket, without (oh, no!) the tiger stripes.
Use of a shim washer is not necessary if assembly is done correctly and diaphragm spring is serviceable. I did not assemble using a shim washer.Comment
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Re: who rebuilds fuel pumps 40083
Thanks Joe - I will have to check my pressure, however in a FI car it's a little less important before one would see problems but good point which needs to be checked (another little job)
BUT what is the real story on the yellow v red strips?Comment
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Re: who rebuilds fuel pumps 40083
The first photo shows an original pulsator cover diaphragm, courtesy of Bill Clupper.
Second photo shows how the original reinforcement fabric is obviously apparent in an original diaphragm, and how thick it is:
The last photo shows the markings on an original screw head from a 40083 pump:Comment
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Re: who rebuilds fuel pumps 40083
Thanks Joe,
Same as mine! Have you been finding part numbers/dates inside main housing?Comment
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Re: who rebuilds fuel pumps 40083
Joe, Nice post you made here. I am happy you pointed out that Classic Preservation Coalition provides a pump rebuild kit compatable with todays crap gas.
I will tell the rest of you that a typical repro pump rebuild kit is NOt compatable with ethanol, methanol and other mixtures of gas. I have prove for sure. That bottom plate held on with two fillister head screws is bound to leak with ethanol. Been there.
Don't forget to update your fuel line to pump rubber hoses also. If you don't believe me take a hunk of your original rubber hose and submerge it in ethanol and watch it grow to twice it's size overnight.
Again nice job Joe. I see the two different color-yellow and red stripes on various pumps I have. Airtex used red and AC used yellow or vise versus. That doesn't ring my bell. But the newCPC kits sure do.
The screws have a washer head with the logo and are typically blackened on a 4657. I don't know what the finish is on the 40083.
Alan. Typically you will find a date as to when your pump was built in the round hole above the inlet fitting of the pump.
I just saw a NOS 4657 fuel pump on ebay advertised as correct for a 63 but it is not. It's a SR but is correct for say Dave Kitch's 66 300HP. Has the two frog pads on it. John D.Comment
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Re: who rebuilds fuel pumps 40083
The 40083 pump was only used for a few years, 64-66 Corvette and some older Caddies, too. Then Chebby began using the non-rebuildable crap pumps in 67. The magnesium pump housing is very noticeably lighter than the potmetal used on other models! A real deal pump of this sort is rare.
The Goat's ass had one awhile ago, real deal fully rebuilt for fairly big bucks.Comment
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