Found a big puddle of gas under my 1977 L-82 powered vette. It looks like the leak is coming from the fuel pump. I put the car up on my ramps and started it. Gas is dripping off of the fuel pump, but it doesn't look like the lines that attach to the bottom are the source. I also checked the fuel line where it attaches to the carb and that conneciton is bone dry. It appears that the fuel is leaking from the top of the pump and is running down. Is this possible?? Also, it looks like it is a devil to get at to replace. Any advice on how to do it from someone who has done it?

 

Daniel - I have a 79 model, getting to the pump was not that bad, I loosened the A/C compressor and it was right there. I removed the 3 lines to the fuel pump and then removed the 2 mounting bolts and it came off. After replacing the mounting gasket slip the pump back in making sure the pump shaft is on top of the pump lever and bolt it back on. Inspect the fuel lines, replace if necc

 

Another way is to put the front up on jack stands, and get to it from the bottom. I'm not sure when this started, but the 81 has a bolt in the front of the block that will let you hold the fuel pump rod in place when you put the new pump in. You just snug it up to hold the rod, replace the fuel pump and back it off. Another method I've used is to let the pump rod drop, then use wheel bearing grease on the end, slide it back into the block and it stays up in the hole so you can get the fuel pump under it.

 

Thanks to you both. Looks like I will be busy this weekend. Any suggestions on where to get a pump (other that the local chevy dealer). I have seen them various places on line ranging in price from about $35 to $70.

 

The leak is most likely from a ruptured diaphragm. Make sure that the engine oil is not contaminated before you run the car again.

Most places like NAPA carry replacements. Beware aftermarket pumps with only two ports.

 

Mike, Thanks for the heads up. I didn't realize that this could cause gas to get into the engine oil. Oh well, it's due for a change anyway.

Dan

 

Well, I finally got around to doing this a couple weeks ago. Here is what I learned.

1. On my 77 with air conditioning, there is no way to get at the fuel pump from the top.

2. Put the front up on jackstands and remove the right front wheel. The suspension will drop down enough to allow just enough room to remove the pump.

3. Use a long extension (12 inches) on a socket wrench to access the two retaining bolts through the wheel well.

4. Use a golf tee to plug the fuel supply line. Gravity causes the fuel to run out after the line is disconnected from the pump.

5. After 30 plus years it is really tough to unscrew the metal line that runs from the pump up to the carb. Buy a 5/8 inch flare nut wrench BEFORE you damage the nut.

6. Remove the separate cover from the block and let the rod drop out. Goop it up good with grease and insert in the block. The grease will hold it in place so you can re-install the pump. To get the rod in its max in position, use the starter motor to rotate the engine to TDC on number 1. This will be either max in or out. I figured it out using trial and error.

7. Try to put everything back together. Make sure no small children are within earshot. Tip the pump up to get the lever arm on top of the rod and slid it down in position.

8. Use sealant on the threads of the nut when you re-attach the metal supply line up to the carb.

9. As long as you are at it, for 19.95 you can replace the two short rubber lines that connect the pump to the metal supply and return lines on the frame rail about 6 inches above the pump.

10. I got my replacement pump and rubber lines from Ecklers. The pump was a genuine Delco part. All in for the pump, hoses and shipping was less than $100.

Good luck!

 

Hello
DanielA has some good advice on his post.
If you can replace the two rubber S shaped hoses that go from the ard line to the pump you should do that also. Depending on the age of the car, how long you had it, previous history, etc. you might not know how old these hoses are.

I replaced the hoses on my 75 soon after I got it. They were cracked and leaking from either being too old, or not driven enough.

kdf

 

Yeah...and fun reading as well!

I came across a leak on the 78 but it the rubber hose off the ports on the top of the gas tank. The rubber hose connector was cracked that connects the fuel tank sender ports and the fuel lines. I ended up having to loosen straps on tank and drop it slightly enough to get up in there to remove and replace all rubber hose connectors. Some effort but I don't smell gas no more.

 

Hi I just discovered the same problem on my fuel pump yesterday leaking from the top on my 1977 L82 non-ac manual 4 speed.
Can you help me with Line Item#6 ? Remove the separate cover from the block and let the rod drop out. Goop it up good with grease and insert in the block. The grease will hold it in place so you can re-install the pump. I do not understand what your explaining in this step. Also, did you purchase your fuel pump from ecklers or NAPA?
Thank you
Mike

 

Mike, I has been a while since I did this, but I will try to describe it as best I can. I got my pump from Ecklers (see my point 10). As to step 6, there is a steel rod about 3/4" in diameter that rides on the camshaft and pushes on the lever arm on the pump. The rod is inserted into the block at an upward angle of about 45 degrees. As soon as you remove the old pump, gravity causes this rod to drop down about an inch. In order to get the new pump on, the rod needs to be held in the up position so that you can get the arm on the pump under it. Some folks try to use a hacksaw blade to hold it up while they insert the pump, but I had no luck with that. Once you have your pump off, you will see a separate cover on the block. When you remove this, the rod can drop all the way out of the block. If you goop it up good with some heavy grease, the viscosity of the grease will hold it up against the cam when you reinsert it in the block. Then you can put the cover back on and install the pump. Good luck. This is not easy. Dan

 

Thank you Dan!
I will attempt to R&R Mid June when I get back to the states.
Stay tune for an update.
Regards,
Mike

 

There's an easier way. There is a bolt hole in the block in front of the fuel pump push rod passage which goes all the way through to the push rod. remove the bolt that seals the hole and get a longer bolt in the same size/thread. Insert the longer bolt in the hole and snug it up against the fuel pump push rod to hold it in place while you swap the pump. When the new pump is installed, remove the longer bolt and insert the original to seal the hole from oil leakage. A little sealer on the threads is helpful. I use Teflon pipe sealant.

 

Exactly what I did when my 70 dropped half a tank of fuel on the garage floor after the diaphragm failed, the holes in the pump housing are there to allow fuel to leak out rather than into the sump which is where you'll see the fuel coming out of. A bit tricky because of the tight space but didn't take too long to change.
Graham

 

Does anyone remember the thread pitch and length of bolt for this? Looks like I'll be doing this project soon.

Also for the hoses...order these two?
https://www.ecklerscorvette.com/corv...1970-1981.html

https://www.ecklerscorvette.com/corv...1968-1981.html

Or alternatively:
http://keenparts.com/CorvettePartsDi...lex%20S%20Line

Thanks,
Vick

 

It's a 3/8" NC bolt and I think 1-1/4" is long enough.