Corona fuel pump

Reassembly after cleaning...blued base plate first. It has a small key tooth that matches an indentation in the body of the pump so hard to get this wrong as it won't go in upside down. Notice how the pump body inner diameter is eccentric.
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Stainless ring next...a little lube to get this in as it is very snug...goes in by hand though.
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Pump rotary center next...don't lose a vane! It goes in with the top forming a smooth surface when the magnetic shaft is in place from the other side...like this...
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NOT like this...
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This pic shows the pump magnetic shaft. The little bearing goes on the top of the blued iron weight and falls out freely. To get the pump back together, make it look like the correct picture above by placing the magnet shaft up from beneath and into the pump center and ensuring the step cut in the shaft engages the center. Next place the gasket and end cover over the pump side and hold them together by hand or masking tape ensuring that you don't release upward pressure on the magnet shaft else it will fall out and will be difficult to replace as the pump center can move off center so realligning it will mean opening the top again. You can now turn the pump body over so the magnet shaft is up and the bearing can be set in it. Next, the magnet body needs to be replaced. This requires something skinny, I used a toothpick, to hold the magnet shaft in place from the side as you replace the body...why? Because the magnet body will pull the shaft out of the pump as you try to put it on so you'll start over a couple times like I did! Once back together, three cad plated screws and the pump side is good.
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Finish notes. On my pump the bodies appear to be aluminum alloy. The motor cover, mounting clamp with its nut, bolt and washer are yellow cad. The three body bolts are yellow cad as is the end plate.

 

This thing will come apart again when I send parts for plating after I check it's function again. I'll post a pic of the magnet body as I forgot to take a picture of that...sorry.

Also, if anyone has any tips on this, please let us know. I don't really know squat about these pumps other than what I posted.

Questions: I started pressing out the bronze center magnet shaft bearings hoping that would let me get the screen off, unfortunately this is a two part bearing and I was afraid I might push one into the center of the pump body and not be able to retrieve it if the screen would not come off. Also, there was one tiny bearing on the motor side that I assume went at the apex of the motor shaft...no other bearings. Does anyone who has done this before know if there are suposed to be several tiny bearings running in a race at the apex of the motor?

 

Will, beautiful documentation, thank you!

Regards, Alberto

 

I'm looking for a corona fuel pump, gold cad cover - anyone have one they'd be willing to part with? PM me.

 

+1

 

I haven't been able to find the later yellow cad plated Corona fuel pump, but I did manage to find an earlier black painted pump. I've disassembled, cleaned, restored, and reassembled it, and it appears to work well. Because the pump is assembled a little differently from the later model, I thought I'd go over what was involved in reconditioning it.

The pump has three main parts: the pump chamber with the input and output fittings, the electric motor base, and a cover for the motor.

At the base of the chamber is is a simple centrifugal mechanism, with a small chamber and an eccentrically mounted impeller with slotted vanes that slide outward to the chamber walls as the impeller spins. There's a mesh screen to filter particles out of the fuel. At the top of the chamber is a cylindrical magnet joined to the impeller via a shaft (press fit on both sides). The magnet couples the impeller to the electric motor while isolating the motor from the fuel passing through the pump chamber.

The motor is just a basic permanent magnet electric motor and looks quite robust. The casing is a metal cylinder with a separate cap; rather than the peens that the later model uses to secure the casing to the motor housing, this model secures the casing to the motor base with two long screws. It took me a while to figure that out because the casing looks like it was dipped upside down in thick black paint, which got into all the crevices and splashed onto the motor housing, hiding all the assembly details. Crude but effective protection from the elements, I guess.

The motor has only one electrical terminal (positive), which passes through the casing via an insulated connector. This was also covered with black paint that took some effort to remove. Ground is to the pump body.

There are two O-rings, one that seals the top of the pump chamber to the motor base, and one that seals the bottom of the pump chamber to an end plate. Three screws on the end plate fasten everything together.

Here are some pictures of the bits after I spent a bunch of time removing all the gunked on black paint using paint stripper, wire brushes, and a bunch of elbow grease. You can see the mechanism's pretty simple and, apart from a little bit of corrosion, in surprisingly good shape for a 40-odd year old part.
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The O-rings were in great shape, so I just cleaned them and left them alone. The motor was in similarly good shape, just needed a good cleaning to get years of dust out. I used a little tri-flow lubcricant on the top of the motor shaft.

The pump chamber needed some cleaning in lacquer thinner to get accumulated varnish out. The impeller had a little corrosion on it, which I wire brushed off. The impeller vanes were in great shape. No idea what they are made of, but 40 years of contact with gasoline didn't seem to have affected them at all. I also removed the shaft connecting the impeller and its magnet, cleaned some corrosion off it, lubcricated with tri-flow, and reassembled. Everything is press-fit and easy to disassemble. The chamber itself looks like it can be removed, but was a really tight fit and since it looked in good shape, I left it alone.

Here's a picture of the impeller and magnet, and the top of the pump chamber. Be careful not to lose any of the vanes - they slide out quite easily. Also note they aren't square; make sure they line up properly with the top and bottom of the impeller. The magnet has a small bearing press-fit into the top, another thing to be careful not to lose. I lubricated that as well.
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I sent the mounting clamp, casing, base plate, screws, and washers off to be yellow cad plated. They came back looking quite nice. The top of the casing looks like it's pot metal and has a slightly different look to it when plated.

Reassembly was straightforward, just remember not to lose those vanes!

The pump had a sticker on it which was in pretty bad shape. I managed to scan it and send it off to my sister, who's a graphic artist. She vectorized the image and cleaned it up, and I used the result to print onto vinyl labeling. Add the part number with a rubber stamp and it looks pretty good!

I've ordered some clear fuel line which I'll use to test the pump for a while and make sure it works.
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Great reference Mark, thanks. I was clearing out my old parts yesterday and came across the old corona pump, I may have a go at restoring it as well. love the sticker!

 

Let us know if it works. I noticed you have no plastic sheet insulator over your positive terminal...see earlier in the thread where I go over this pump. If rouns poorly, this may end up being why. You stated the motor only has a positive terminal. It has both positive and negative terminals with the positive going to the single wire, and the negative connected to the case via a copper wire. The positive terminal on my pump had a thin plastic sheet over the periphery so it would not ground or arc to the negative case. Great pics!

 

04124 1972 July build has a black Corona pump I am the original owner.

 

04124 blk Corona pump with silver filter
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When I said my pump had no negative terminal I meant an external terminal - you're right, it's grounded to the case.

My version of the pump doesn't have the plastic insulator, and it's not obvious how you'd attach one if you wanted to - the design's slightly different from the later gold-cad model.

I ran the pump for about 10 minutes and it worked like a champ. It's a pretty simple design. I'm used to SU fuel pumps on British cars, and they are quirkier.

 

Looking back in this thread, there are a few photos that show what looks like a condenser (capacitor) mounted next to the fuel pump. I found mine in a box of old fuel-related parts - looks exactly like what's in the photos, and is marked "0.5 uf". My car currently has a modern Facet pump which I'm about to switch out for the original Corona pump. I can't find the condenser in the parts book; is it required for use with the Corona pump? Any idea what its function is and how it's wired up?

 

Does anybody know where you can buy the small vanes for the impeller for the BCD Corona pump?

Is it possible that they can made by cutting small strips from a sheet of nitrile rubber of the correct thickness?

regards Sam

 

I doubt it as there are many different types of (N) rubber with varying hardness values to consider.

 

I have written to Corona BCD in Italy in the off chance that they could help. To my surprise I had a quick and gracious response from the technical division which I would like to share with you.

"After the pump's production for the new cars, we kept producing that family of electric fuel pumps for decades, but it was eventually stopped about thirty years ago. I am sorry to inform you that currently we do not have anymore pumps nor even available components in our stock.
You should look for it in vintage specialised workshops, or try to handcraft some replacement vanes.
Material should be like Bakelite or similar (must not swell in petrol) and the critical most dimension is the height, i.e. exactly the same of the metal rotor thickness. The vane must be free to move for centrifugal force in its hollow.

I hope you can accomplish to keep rolling your superb car on the road.

Best regards,
Sandro Baggio
-------------------------
Servizio Tecnico
Corona & C. s.p.a."

I think it so nice that they took the time to respond and I would like to publicly thank them for that and they hope we keep our superb cars on the road and running.
Sam

 

Thats nice, well done BCD but spare parts would be nice.

For piece of mind i would fit the Facet pump FEP60SV. Its perfect for the 246.

Tony

 

Agreed! Personally, I have 2-3 rebuilt BCD pumps but am hesitant to install. The Facet pump above described works better! stay with that.