Leaky Edelbrock Fuel Pump

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KOZ45

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I have an Edelbrock Performer #1723 mechanical fuel pump

It is either leaking fuel from one of the two fittings or from the gasket for the two halves

Anyone else have this issue? I am ready to junk it!

I have removed it three times this weekend and its still leaking

Any ideas?
 
I noticed in mine the NPT threads were not tapped deep enough. Mine to seals, but I used a liquid seal that was gasoline rated. You can gall aluminum threads easily. What all did you used for fittings and sealant? I have had NPT fittings that never would seal and replaced them and all was good.
 
dano said:
I noticed in mine the NPT threads were not tapped deep enough. Mine to seals, but I used a liquid seal that was gasoline rated. You can gall aluminum threads easily. What all did you used for fittings and sealant? I have had NPT fittings that never would seal and replaced them and all was good.
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I used Teflon tape

Snapchat-1081776269.jpg


Snapchat-1081776269.jpg
 
If you over tighten it, you’ll crack the case…. I did once :(

Edelbrock sells rebuild diaphragm kits, BTW.
 
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dano said:
I noticed in mine the NPT threads were not tapped deep enough. Mine to seals, but I used a liquid seal that was gasoline rated. You can gall aluminum threads easily. What all did you used for fittings and sealant? I have had NPT fittings that never would seal and replaced them and all was good.
Click to expand...

do you have a link to the gasoline rated liquid seal ??
 
im not a big fan of teflon tape near the fuel system
it can get into the lines and clog stuff up

for my money, i use permatax aviation #3

its the franks red hot of sealants

Permatex 80019 Aviation Form-A-Gasket No. 3 Sealant, 4 oz. | eBay


of course, you can seal the fittings all you want, if it is leaking from the diaphragm, that wont do you any good

so what have you done to inspect that?
 
I removed both fittings

The Teflon tape was falling apart, like the gasoline deteriorated the tape

I then chased each hole with a 3/8" tap, since one fitting was only 2-3 threads deep (shown below by the tape line)

I'm going to buy some gasoline rated thread sealing compound and reinstall both fittings

Snapchat-900153453.jpg
 
KOZ45 said:
I removed both fittings

The Teflon tape was falling apart, like the gasoline deteriorated the tape

I then chased each hole with a 3/8" tap, since one fitting was only 2-3 threads deep (shown below by the tape line)

I'm going to buy some gasoline rated thread sealing compound and reinstall both fittings

View attachment 1715754131
Click to expand...

Exactly what mine did, they seem to not be tapped deep enough. I know there is a "L1" Gauge that tells you the proper depth for NPTs to be tapped for proper fit. For the price, I'd think these would be tapped correctly.
 
dano said:
Exactly what mine did, they seem to not be tapped deep enough. I know there is a "L1" Gauge that tells you the proper depth for NPTs to be tapped for proper fit. For the price, I'd think these would be tapped correctly.
Click to expand...

i think that’s how I cracked one. Didn’t look like it was screwed in far enough…. Kept tightening till it cracked the case.
 
And a regular tap wont work unless you grind it shorter or buy one. I've dealt with this a lot at work. Most shops need to make there own tap to get the L1 right if they can't go any deeper when even the short taps are not short enough. Probably why other pumps are 1/4 NPT, that would give you more tap depth.

This might help if someone is looking to tap theirs deeper or need to repair.

McMaster-Carr

And if you want it right.

McMaster-Carr
 
Thanks

I'll pick up a short projection tap also to make sure
 
Found this:

As a general guideline, after hand-tight engagement, tighten 2 full turns for sizes up to 1 inch for NPT thread fittings.

You should have between 3.5 and 6 engaged threads. Any number outside of this range may indicate either under or over tightening of the joint or out of tolerance threads.
 
CRUZE 418 said:
Chrome plated probably doesn't help either.
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Mine were anodized aluminum Earl's. It messed the thread up on one of them.

Those could be nickel plated brass or steel too. I have had fitting be out of spec and have split them tightening them for small leaks. Its uncommon but does happen.
 
I might also use a small wire wheel in the threaded port and try to remove the chrome plating
 
The reason I mention the chrome plating, I couldn't get my thermostat housing to stop leaking, didn't like the chrome anyway, it came wiuth the car. I sanded the chrome off the bottom and a pass on the intake base, finally stopped the leak. Do not know why they chrome that pump , it just adds to the cost. Come to think of it, their carbs look kinda chrome too. Do not know if they heat treat the chrome, chrome causes hydrogen embrittlement, cracking, failure.
 
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I'll try the new sealant and if all else fails, I'll just buy a new plain Jane Carter
 
Hopefully it will seal, it should. The plain Jane seems to to be on back order till sometime next month, M6270. Says now September. Hope that you are able to get a handle on yours!
 
New fittings, new thread sealant

Still leaks and cant maintain pressure

I am going to buy a new pump, plain bare metal finish

I am using 3/8" barb fittings with 3/8" NPT ports, that go to rubber fuel hose

Whats a good solid pump with 3/8" ports?
 
Summit has the M6903 Carter Street Super in stock for $87
1/4" NPT IN/OUT and 120 GPH
 
The M6903 should be good.
'Should be' because companies change stuff and we only find out the hard way.
The Holley '110' mechanical pump p/n 12-360-11 has been a solid performer for me.

Mechanical Fuel Delivery for Mopar LA Engines

Mopar Performance and Edlebrock had 6 valve pumps which should work fine IF installed on an engine with a '69 down water pump.
 
I ordered a new Carter pump and new fittings.

Should be delivered Monday
 
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