NEED HELP,FUEL PUMP BOLT ISSUE,LEAKS OIL

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1968 Dart 270

1968 Dart 270

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Hi,I’m having another problem now with my 1968 Dart. It has a 360 in it. Anyway when I bought it I started noticing a leak under it. I assumed it was gas but it’s oil. I replaced the fuel pump today with a new one and new gasket. When I went to remove the rear bolt,the one closest to the firewall,I noticed it wasn’t tight like the one closest to the front of the car. I made a note of which bolt came out of where. The longer bolt came out of the side facing the rear. I put in the new pump and gasket and went to tighten the bolts. The front tightened down fine. The rear is stripped and just spins. That’s why the car was leaking oil (which I assumed was gas). Any ideas what I can do?
What size threads are the original bolts? Should I go a size up? How long is the back bolt supposed to be.
So far it’s been one thing after the other with this car. Don’t know how someone managed to strip the bolt. I just need to get this fixed so I can drive it.
 
Try a 1/4" longer bolt and just snug it up.

Clean the pump gasket surfaces clean, and then break parts cleaner to remove any and all oil film.

New gasket, Black RTV gasket maker on all surfaces including both sides of the gasket, thin film.

Assemble snug but not extremely tight. Let it sit overnight to cure.

Fire it up again, should not leak.

Screenshot_20230131-220220_Gallery.jpg


1964 Norway Dart 340 ^^

☆☆☆☆☆
 
I’ve never seen two different lengths of those two bolts.
I suspect the different length was the cause of the problem.
 
George Jets said:
Try a 1/4" longer bolt and just snug it up.

Clean the pump gasket surfaces clean, and then break parts cleaner to remove any and all oil film.

New gasket, Black RTV gasket maker on all surfaces including both sides of the gasket, thin film.

Assemble snug but not extremely tight. Let it sit overnight to cure.

Fire it up again, should not leak.

View attachment 1716042438

1964 Norway Dart 340 ^^

☆☆☆☆☆
Click to expand...

Thanks George,I used Gasgacinch on the gasket the first time and did clean the surface with brake cleaner. I was really disappointed when I discovered someone stripped the bolt.
Do you know what size threads the bolts are? I haven’t pulled it off the car to take it with me. I’m not sure how far the bolt can go into the block.
 
Could you run a tap in there and a larger bolt without any metal/aluminum getting into your crankcase?
Will a larger bolt pass through the pump to mount again?
 
QUINN FORBES said:
I’ve never seen two different lengths of those two bolts.
I suspect the different length was the cause of the problem.
Click to expand...

I wasn’t sure if they were supposed to be different lengths but the bolt appear to be original. It looks the the shorter one in the front is that way because it can’t go as far back. I sure wish people would be more careful when they put things together. Once the carb is working good and this oil leak is taken care of this will hopefully be a reliable car.
 
Google helicoil.

That would be a propper fix.

If you go that route you will need to figure out a way to catch ALL the metal chips.

You could always replace the timing cover.

The bolts may be correct or not.

My bet is they should not have a shoulder, but if they do it will be short.

A long shoulder can bottom on the timing chain cover before the pump is torqued to spec, leak then PO decided it needed to be tighter and wham! Now it's stripped. The FSM calls for 30ft lbs on a 383 but that is into cast iron. I would suspect that into the aluminum triming cover 15 would be max. (I could not find a reference in the 67 FSM)

Whenever I am in doubt I take a piece of coat hanger wire and insert it into the hole that the bolt goes into. When it bottoms out I mark it. In this case you would mark it at the edge of the fuel pump where the head of the bolt would sit when installed.

That is the longest bolt that can go into the hole.

Take another wire and bend a short "L" to the end. Insert it in the hole but pull it back till it catches the back side of the hole. Mark it, that is the shortest bolt.
Just because you can insert a 4 inch long bolt into the hole does not mean you should. The bolt should be just a bit longer than the shortest.

My bet is both bolts are supposed to be the same length maybe 1.5 to 2" long.

Both bolts are going into the timming cover, the rear one into the timing chain space with oil, the front one to outside the engine


Back side of front bolt hole
Screenshot_20230131-200409~2.png

Back side of rear bolt hole
Screenshot_20230131-200429~2.png
 
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QUINN FORBES said:
Could you run a tap in there and a larger bolt without any metal/aluminum getting into your crankcase?
Will a larger bolt pass through the pump to mount again?
Click to expand...
I was concerned about that very thing. Metal shavings in the engine if I tried that.
 
Dana67dart,Thanks for the great post and the photos. That explains why the rear bolt was longer. It can go further into the casting. What a pain in the *** because if a stripped bolt. Hope it can be fixed without replacing that whole assembly.
Do uou happen to know what thread size the bolts are? I can’t pull mine out until tomorrow morning.
 
1968 Dart 270 said:
Do uou happen to know what thread size the bolts are? I can’t pull mine out until tomorrow morning
Click to expand...
Nope sorry. Try googling fuel pump bolts small block Mopar.

If you inlist the help of a friend with a vacuum you could probably slowly drill out the hole and tap it without getting too much material inside the engine

REALLY BAD IDEA.....

you MUGHT be able to put a bolt in through the fuel pump hole then into the stripped hole to the outside. The bolt would need to have a way to keep it from rotating, like cutting a slot in the end for a screwdriver and a way to keep it from slipping back into the engine. (Speed nut / one-way washer, JB weld???)


Good luck
 
Not sure what the hole diameter is on the small block but a manual brake master cylinder stud, or other if that's the wrong size, could be put in through the pump hole and then drawn tight using a nut as an install tool.
1966plysathp2ptd 129.jpg
 
1968 Dart 270 said:
I was concerned about that very thing. Metal shavings in the engine if I tried that.
Click to expand...
I would stuff a new microfiber cloth in the fuel pump hole. That will keep shavings from getting in the engine. I'd get one about the size of a washcloth and leave enough hanging out so that it can be pulled out easily. You could also clean off the mating surface on the engine and use GOOD duct tape. I really like Gorilla brand duct tape. It costs more, but it is heavier and sticks better than most. Anyway, I would definitely go the Heli Coil route. I have used them a lot, and I have always had good luck with them.
 
If you use a tap to put in a Helicoil, coat the flutes of the tap with wheel bearing grease and go very slow. The grease will catch the aluminum pieces and the won't fall in the pan. Other than that, pull the timing cover and Helicoil it.
 
The fuel pump bolts are a special bolts. They are the same and have a fixed face on them . Heli-coil is your only fix. I would do it in the car as stated above with grease on the tap. or have someone hold a small hose at the tap and the drill bit taped to a vacuum. A small amount of aluminum won't hurt anything It will get caught in the filter.
 
Heli coil it. It's not gonna get fixed blabbin about it on a forum.
 
Oldmanmopar said:
The fuel pump bolts are a special bolts. They are the same and have a fixed face on them . Heli-coil is your only fix. I would do it in the car as stated above with grease on the tap. or have someone hold a small hose at the tap and the drill bit taped to a vacuum. A small amount of aluminum won't hurt anything It will get caught in the filter.
Click to expand...
Do you know which size helicoil kit I would need? What does “fixed face” mean?
Thanks for the tip about putting grease on then tap. Hope there’s room to do that.
I watched this video last night. It shows there being a “tang” that needs to be broken off with a punch after the helicoil is installed. How would I drive that out within the it falling inside the engine?



He also shows other methods. One is soom “thread restorer” stuff by locktite.
 
When I fix things, I like to do it once and permanently.
To me that means Heli-coil or Keensert. There may be enough room to do it on the car but if not, remove the cover first. The hole has to be drilled out and tapped to the proper size for the insert. Right angle drill?

And any fastener that that goes into a cavity must have sealant on the threads. That's the rear hole, the front one is blind and doesn't need sealant.

Reminds me of the time I took my car out of storage and while blowing the carbon out, the rear exhaust header bolt actually blew out. Steam everywhere. Small block heads have exhaust bolts on the end that go into a water passage and the wall is very thin. Previous owner had stripped it. Took the heads off and heli-coiled them.

Sounds like a previous owner just grabbed whatever was on hand and threw it together. Typical.

BTW, if the bolt head has a 1/2" head it's 5/16-18 UNC. If it's 9/16" then it's 3/8-16 UNC. A general rule of thumb is aluminum should have 2X the bolt diameter thread engagement. One bolt diameter engagement for steel or cast iron.
 
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1968 Dart 270 said:
Hi,I’m having another problem now with my 1968 Dart. It has a 360 in it. Anyway when I bought it I started noticing a leak under it. I assumed it was gas but it’s oil. I replaced the fuel pump today with a new one and new gasket. When I went to remove the rear bolt,the one closest to the firewall,I noticed it wasn’t tight like the one closest to the front of the car. I made a note of which bolt came out of where. The longer bolt came out of the side facing the rear. I put in the new pump and gasket and went to tighten the bolts. The front tightened down fine. The rear is stripped and just spins. That’s why the car was leaking oil (which I assumed was gas). Any ideas what I can do?
What size threads are the original bolts? Should I go a size up? How long is the back bolt supposed to be.
So far it’s been one thing after the other with this car. Don’t know how someone managed to strip the bolt. I just need to get this fixed so I can drive it.
Click to expand...
Seems like you are new to the car, why not get what you need to replace the timing chain and water pump and bond with your car. You will learn a lot and you can fix your fuel pump problem while you're at it.
 
mrs49 said:
Seems like you are new to the car, why not get what you need to replace the timing chain and water pump and bond with your car. You will learn a lot and you can fix your fuel pump problem while you're at it.
Click to expand...
I like the idea. New or good used timing cover at the same time.
 
Use a standard heli-coil kit. 3/8 - 16. The bolts look like they have a washer built on but it is part of the head of the bolt and thicker then a normal washer. It does not spin separate from the bolt.
 
The thing we are all overlooking is the fact that even with a helicoil, he would first need to drill out the existing threads

Not sure if you can grease a drill bit to catch those shavings

I like the idea of removing the pump and snaking a bolt on from behind IF there is room

Of course, one fals move and that front cover will need to come off
 
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