robertfrost

I want to fit a larger oil sump to my 454 C3 (1974). How is the oil dipstick tube fitted and sealed to the pan orifice? Anything special how to remove it from the old pan and fit it into the new one?

thanks & regards

Fritz

flyeri

If it is a stock style pan it is probably held in with silicone. Mine has an o-ring that slides up the tube to a flange. The tube just slides in and the o-ring/flange bottoms out in the orifice. Put a bit of silicone around it to help seal and keep it in place.

robertfrost

Thanks for this info! My pan is still the untouched original from 1974. Due to "nowadays" traffic in Germany (jams and high speed) I think it is better to fit a pan with extended capacity (about 1 additional liter) although I always try not to torture the engine anyhow.

7T1vette

Silicone is not the best product to use for that purpose...unless it is RTV UltraBlack. It would be better to use something made to seal fuel/oils. Most silicone products are not good for that and will leak in short order.

jb78L-82

I need to seal my dipstick tube as well. I am going to get an o ring to fit the tube from Lowes/HD first and if that does not seal the tube totally, RTV ultra black or ultra copper, either one will work…just cleaner looking with the correct O ring…

robertfrost

I wonder how the tube had been sealed to the pan orifice by the factory?

jb78L-82

That's a good question…When I rebuilt my L-82 last Spring 2014, there was nothing on the dip stick tube to seal it to the block. Looked in the the 78 AIM manual and no reference or pictures to dip stick tube. Anyone know what the factory did?

flyeri

Thanks for correcting. RTV is what I was referring to.

jb78L-82

Stopped at Home Depot today and picked up a pack of O rings for $2.77…needed just one but it slipped on tight and is in. Will see the next time I drive the 78 what it is worth...

7T1vette

I believe the factory process is that the dipstick tube is a slight press-fit into the hole in the block. With years of vibration, etc. that fit loosens up some. If the PCV system is still functional, there should not be any positive pressure in the crankcase that would force oil out of the tube or around it.

Zorro O

When I put the new motor in my car, the old dipstick was way to small. The new stock one for it needed to be tapped in. No RTV needed, just a block of wood a hammer and a gentle touch. Funny those words don't seem to go together, but it works.

Zorro

7T1vette

I'm sure that GM designed, then purchased, a $5000 precision tool for that installation process. But, on the assembly floor, the workers probably used the "block of wood" approach.

Cavu2u

Permatex #2 perhaps?

7T1vette

Good choice...

Frankenvette

I faced this question about 15 years ago. I too simply added an o-ring... no use of RTV, permatex etc... I've never had a leak since.

jb78L-82