Need Help - New Fuel Pump

gbullman · Post by **gbullman** » Sat Sep 25, 2021 9:02 am

My existing Fuel Pump starting leaking again but this time screws started stripping before it stopped leaking.I purchased a replacement a while back but only took a quick glance at it when I received it. Now I see that it doesn't have the retaining hole drilled into it.

How does one position the retaining hole when the length of exposed shaft and the overall length of the boss are different than the old pump.

My gut is telling me I should position the hole relative to the end of the shaft since the shaft would then be in the same relative position to the mounting bolt and plunger as the old one was. Is that correct?

I just want to get it running now but an electric pump conversion may be in my future. Reading a lot of bad press on available Corvair mechanical fuel pumps these days.

terribleted · Post by **terribleted** » Sat Sep 25, 2021 9:10 am

The best answer is to source a proper fuel pump and deep six that junk new one. Personally I convert to electric pumps and forget about the trial and tribulations of new mechanical pumps which have been hit or miss for many years.

You would want to drill the hole at the same distance up from the end of the pump rod as the old one would be my thought on this. make sure it is in the correct place around the bottom of the pump to locate the output pipe facing straight forward like the original when mounted.

I would also suggest checking the output pressure once you get it mounted. Hopefully it is in the 2.5-5.5PSI range that is acceptable. A number of aftermarket pumps over the years have made too much pressure causing flooding.

gbullman · Post by **gbullman** » Sat Sep 25, 2021 9:21 am

Thanks Ted,

I've been doing additional checks while waiting for answers and discovered the rod / diaphragm doesn't move as far on the new one either so I think I'm really stuck. I'm going to reach out to the seller and see if I get any satisfaction there.

Likely I'll be going the Electric Fuel Pump route now since it seems like Corvair Mechanical Fuel Pumps are not reliably available.

Oh well, missing out on a great weekend around here.

Post by **bbodie52** » Sat Sep 25, 2021 9:29 am

What was the source of the pump? Any chance of returning it??? I would not use that pump at all!

There are already existing quality control issues that you can see, and what about the ones you cannot see? I have read about a period of time when many manufacturers were producing Corvair reproduction mechanical fuel pumps that had a very high failure rate. Problems included internal springs that produced output pressure that was much too high and could flood the carburetors. I also read about pumps made with cheap, poor-quality substandard diaphragm materials that would tear or develop leaks. A failure of a substandard fuel pump could leave you stranded somewhere, or having to pay a high towing fee. An internal fuel leak can permit gasoline to leak through shaft that leads to the crankcase, and can fill your engine crankcase with gasoline in the oil that could result in serious engine damage!

https://ssl.corvair.com/user-cgi/catalo ... ow_page=65

...We have only been able to locate 2 manufacturers of original style Corvair fuel pumps. Since 1973, we have consistently seen 1-2% of new fuel pumps fail. From about 1998-2001, the failure rate went to nearly 10%! We finally convinced the pump manufacturer that they were using the wrong diaphragm material! Currently, about 1%-2% of the fuel pumps continue to have problems. The problems have usually been seepage of fuel or complete failure resulting in no fuel or a rupture of the main diaphragm. The main supplier (C3403) is now using "antiwicking" diaphragms & has returned to all 3 diaphragms having fabric reinforced material. We've also added a pump from a 2nd supplier (C3403A). Our experience with both is nearly identical. A spare pump is always a good idea

Part number C3403: NON-GM FUEL PUMP-62-69 FITS 60-61 IF C259 ROD USED. ** LIMIT 1/ORDER

Notice: This part C3403 is currently out of stock. You may still order, you will not be charged and you will be notified when we have this part.

Weight: 2 lbs 4 oz
Catalog Page(s): 65
Price:
1 - 1 $66.60
2+ $64.60

Part number C3403A: 62-69 FUEL PUMP REBUILD KITS ARE NOT AVAILABLE

Notice: This part C3403A is currently out of stock. You may still order, you will not be charged and you will be notified when we have this part.

Weight: 2 lbs 4 oz
Catalog Page(s): 65
Price: $99.75

Since these pumps are now in short supply (Clark's is currently out of stock from both of their supply sources, and it is unknown when they will be renewed with more pumps), your best bet may be to make the change to an electric fuel pump coupled with a good inline filter to protect the pump and engine (place the filter between the tank and the pump) and an electronic pump controller. see the following...

ELECTRIC FUEL PUMP CONVERSION IDEAS & SUGGESTIONS

viewtopic.php?f=225&t=17257

Fuel pump not pumping, replace with electric?

viewtopic.php?f=55&t=17355

I noted that the second Clark's pump is now $100 each, and out of stock. The cost of the electric pump I recommended, plus the electronic controller, is about $105. Switch over would also add the cost of a metal-canister fuel filter, and some plumbing hardware change costs. But the Corvair mechanical pump cost is rising and is also unavailable, even from Clark's! It looks to me like the time is now for a switch to an electric pump!

gbullman · Post by **gbullman** » Sat Sep 25, 2021 9:44 am

I reached out to the supplier that I purchased the pump from and we'll see what they say.

As I'm doing more checking I'm concluding that I can't use this pump. My old pump travels at least 1/4" while the new one is about 1/8", something would have to give if I were to try this.

Should have bought a second spare when Clark's had them in stock.

Post by **bbodie52** » Sat Sep 25, 2021 1:12 pm

Whether you can return the poorly designed pump for a refund or not, there are many possibilities of additional internal design and production materials faults that would make it undesirable in your Corvair, as I outlined above and as mentioned in the quote from Clark's Corvair Parts. For the same reasons you cannot expect to cannibalize from the new pump to make the old pump serviceable. You simply cannot trust any portion of the new pump in your Corvair.

As I also outlined above, the availability of replacement mechanical Corvair fuel pumps — now or in the future — is highly questionable. And the price for replacement Corvair mechanical pumps seems to be climbing to far more than a brand-new electric fuel pump! The cost of redesigning and modernizing your Corvair fuel pump system to include an appropriate electric fuel pump with the correct output pressure and fuel delivery volume, proper safety cutoff components, safe, well-designed, and carefully routed fuel lines, a new metal-cannister fuel filter to protect the new electric pump mechanism, and the recommended electronic fuel pump control system, is not that much-more than the $100 (currently unavailable) mechanical fuel pump listed by Clark's. (Click on the link below for more details of my suggested replacement)...

: ELECTRIC FUEL PUMP CONVERSION IDEAS & SUGGESTIONS

viewtopic.php?f=225&t=17257

gbullman · Post by **gbullman** » Sat Sep 25, 2021 1:17 pm

Brad,

More than likely this incident is going to force my conversion to Electric Fuel Pump. My intent is to go with a kit from Clarks and just do it right.

I came to the same conclusion that attempting to take parts out of the new one would not work properly in the old one.

Post by **bbodie52** » Sat Sep 25, 2021 10:15 pm

The total price for the Clark's kit is expensive and the components are somewhat outdated.

Part number C10295: ULTIMATE ELECTRIC FUEL PUMP KIT INCLUDES BOTH STYLES OF SAFETY SWITCHES
This part is a Multi Kit, which contains the following parts:
Part Number C5606: 1 x ELECTRIC FUEL PUMP & FILTER -ALSO ORDER
Part Number C5607: 1 x ELECTRIC FUEL PUMP INSTALLATION KIT *
Part Number C5607X: 1 x SAFETY SHUT-OFF SWITCH WITH FITTINGS TO
Part Number C9848: 1 x FUEL SAFETY INERTIA SWITCH

Weight: 2 lbs 8 oz
Catalog Page(s): 66
Price: $ 250.65

$39.78...Airtex E8251 Universal Solid State Electric Fuel Pump for Marine Applications
Unlike most electric fuel pumps, this pump design draws fuel long distances from the source tank and is recommended for installation near the engine compartment, instead of close to the fuel tank. Operates at 2.5 to 4.5 P.S.I., delivers 30 G.P.H. at free flow, 1/8" N.P.T., 5/16" hose.

https://www.amazon.com/gp/product/B0027 ... UTF8&psc=1

$15.79...K&N PF-1000 Fuel Filter

https://www.amazon.com/gp/product/B00OX ... UTF8&psc=1

$64.99...Revolution Electronics Electric Fuel Pump Controller. Primes the pump on key-on and turns the pump off if the engine stops.
Includes an internal self-resetting 7 amp fuse/circuit breaker and 15 feet of 16 gauge wire to connect the fuel pump.

https://www.amazon.com/gp/product/B00BN ... UTF8&psc=1

https://www.revolutionelectronics.com/P ... _Pump.html