I started my '64 L76 today for the first time in about 2 weeks, and something happened I have never had happen before. It kicked off immediately and perfectly, as it always has over the years, on fast idle and I had the hood up as I was going to go through some checks for my upcoming PV, and I saw gas shooting up out of the two weep holes in the top of fuel pump for about 2 seconds, and then it stopped and all was fine. I started it a dozen times over the next 6 hours and it was perfect, no leaks, so what just happened? I am assuming my fuel pump may be toast and I should rebuild it, but I am wondering if there is something else going on, any advice? Thanks.
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Big Tanks In the High Mountains of New Mexico -
Re: Fuel Pump weep holes
Fuel leakage may now be going into the oil pan instead of out the weep holes. I would check the oil. I would also plan a pump rebuild in the VERY NEAR future.
Larry -
Big Tanks In the High Mountains of New MexicoComment
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Re: Fuel Pump weep holes
Michael------
I would not drive the car again until the fuel pump is rebuilt. Fuel pumps are a maintenance item and should be replaced or rebuilt regularly. This is not just for reliability purposes but also for SAFETY purposes.In Appreciation of John HinckleyComment
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Big Tanks In the High Mountains of New MexicoComment
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Re: Fuel Pump weep holes
Thanks Joe, the parts are on order, and it is spooky to see gas sloshing around in the pump through the weep holes when you shine light down on it. Does that front bolt, when replaced with a longer 3/8th " one, on the block really keep the cam pin in place when you change the pump? I have always used axle grease or a Tampon to do that…...
Michael------
Actually, the holes are not really "weep holes". They are venting holes. However, they effectively become "weep holes" when the internal rubber parts fail.
Yes, installing a longer 3/8" bolt in the upper hole of FRONT motor mount upper bolt. This is, by far, the easiest way to retain the push rod while replacing the pump. I like to use a brass or nylon bolt to avoid any possible damage to the pushrod.
One more thing. You might think about putting a pinch clamp on the inlet hose to the pump. With a Corvette, the fuel tank is higher than the pump. So, the gas can siphon out of the tank and onto the floor of your garage if the pump "gives up the ghost". This actually happened to me many moons ago.In Appreciation of John HinckleyComment
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Re: Fuel Pump weep holes
Been there, done that too. I used to use a stick (dowel) fashioned to a point as a plug, but that still can be messy. The clamp is the best way to keep the gas at bay during the procedure. Sometime ago I bought a special bolt to use in the motor mount hole; it has a spring in the end which holds the pushrods in place. I've only used it once or twice, but even then it paid for itself. I think one could make one of these if you had the machinery to hold the bolt and drill a hole in the end for the spring - naw, never mind.
Stu FoxComment
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Re: Fuel Pump weep holes
My method when doing these in the trade back in the day was to take a bent feeler gauge slipped under the end of the pushrod to lift it up. Slide the pump arm under the feeler gauge and pull the gauge out. Rotate the pump slightly clockwise to line up the inboard bolt hole and start that bolt. Rotate the pump ccw, now against the diaphram spring, to line up the frt hole. Tighten alternately to draw the pump in.
If you're going to lock the pushrod b4 removing the old pump you need to be sure it isn't into it's stroke. Loosen the bolts and turn the engine, watching the pump. If you don't ensure it's off stroke you are fighting the spring to try and line up the bolt holes, no matter what method you use.
Note, there is still a small amount of spring compression even when the pump is not being stroked. It's what stops them from clacking.
SteveComment
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Re: Fuel Pump weep holes
If you don't know the age of that hose, REPLACE IT!!! Engine heat deteriorates the elastomers, and if that hose cracks or ruptures, the entire contents of the fuel tank will drain.
...happened to me once many moons ago in 1975 when removing my SWC from about three years storage in my parent's Seattle garage while the Air Force had me trapped in North Dakota. It was stored with the fuel system drained, but when I added a couple of gallons to the tank it began leaking out of that hose, which was the original that had developed a cracked during storage. I took off the hose and plugged the pipe with my finger while my dad went down to the local gas station with the original hose to get a proper length of 3/8" fuel hose. I think it took him about 15 minutes to get back with the new hose while I played Little Dutch Boy plugging the dike.
Modern fuel hose is more durable, but it should be replaced, AT LEAST every time the fuel pump has to be removed.
DukeComment
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Re: Fuel Pump weep holes
Michael,Thanks Joe, the parts are on order, and it is spooky to see gas sloshing around in the pump through the weep holes when you shine light down on it. Does that front bolt, when replaced with a longer 3/8th " one, on the block really keep the cam pin in place when you change the pump? I have always used axle grease or a Tampon to do that…...
One thing I want to mention when you overhaul the fuel pump is to broach all the surfaces to make sure they are flat.Comment
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Re: Fuel Pump weep holes
Thanks for all the tips guys, and some things have improved in the idea department since my '57 283 and the tampon trick……..
Big Tanks In the High Mountains of New MexicoComment
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Re: Fuel Pump weep holes
This is the bolt hole you want to use to keep the push rod from dropping. Also, if you ever have an application that doesn't use a bolt here for a motor or accessory mount, this hole needs a sealed bolt in it to avoid an oil leak.
SmallBlockChevyOilLeak.jpgComment
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Re: Fuel Pump weep holes
Very few people, other than us old duffs, know what these holes were originally used for; the passenger application for 55 through 57 motor mounting brackets. These engines used a four (4) point mounting vs. the three (3) point (side of block) system begun in 1958. Corvette mounting was even different, as our C-1 owners can attest to.
Although my 63 has a bolt w/washer in that location, I have had a number of Chevy V8 powered vehicles that came from the factory w/o a bolt/plug in this location. Perhaps on the lower HP/RPM engines, the "leak" was so minor that it wasn't worth the price of a bolt and/or a typical passenger car engine would get all mucked up with oil and dirt soon enough anyway as to plug itself.
Stu FoxComment
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