: 1963 Cadillac Coupe having a few issues..

09-14-11, 11:07 AM
Will the original Rochester carb from my 1973 472 fit my 390 on my 1963 Cadillac?
I just purchased a 1963 Cadillac Coupe Deville and I finally got around to driving it after painting it. I noticed that it has a gas leak behind the carburator on the driver's side. The carb is operating normaly. Not much of a mechanic, so I am guessing the carb is in need of a rebuild but I want to drive the car this weekend because I am supposed to do a parade and photoshoot. Is there anything I can check for as far as the leak? Don't want to catch on fire..

I am also having problems with the transmission. It seems to struggle to shift into gear when coming to a stop sign and then trying to get off. In the mornings when the car is cold it makes a hiss sound in the tranny when it finally shifts into gear. All other gears are operating normally. I dropped the pan on the tranny and changed the gasket because it had a small leak when I bought it.

I don't know why it would do that. The car was operating normally when I bought it and drove it two hours from Milwaukee, Wisconsin to Chicago.

Thanks in advance...This site and it's users have always been very helpful.

09-14-11, 03:39 PM
gas from behind carb,,,, check for line leaks or loose clamp

did car sit long before you bought it? rotted base gasket?

sounds like the tranny filter is not on properly as it is sucking air

or it could be clogged up, when fluid is cold it has hard time getting thru the filter

did you change fluid when replaced gasket?

was there many fillings in the bottom of the pan?

do not really know if the carbs are inter changeable for those years and if they are probably would have to rejet

09-15-11, 11:02 PM
The carbs are different... would take a bit of adapting to make it work... I agree with Hardley. Change the filter.. If that does not fix it, then I would change the govenor in the transmission..If you go that route to remove the govenor, as long as it's still has a 63 trans, you have to pull the driveshaft and then take off the tail and the govenor will be right there.. Just pull it out and put in a new one if you can get one . or get a good used one..

09-15-11, 11:45 PM
I think that it probably is going to be the filter. After flushing out the old fluid, I took the filter off thinking I was going to be able to just go to the local Autozone and get a replacement. There is a slight posibility that I did not re-install the filter correctly. I am going to try to get a hold of a new one. As for metal shavings, there wasnt any in the pan. I am going to get under it this weekend. Going to take a look at that carb gasket too.
Thanks alot for your help.

10-18-11, 06:50 PM
Well I changed the transmission filter and made sure everything was good, but I am still having the problem where it wont shift properly. To top it off now I am having trouble with the 390 motor oil pressure. I am not getting any pressure at all. The dummy light is on. and this is not the first time it happens. When I had just bought the car in the beginning of the summer 2011, I encountered the same problem after driving it 2 hours home from where I bought it. I fixed the problem by purchasing an oil pump rebuild kit, and changed the oil & filter. but now after driving it all summer I am having the same problem.Im not sure what else it can be. Now I am wondering if my pump plate (where the gears ride) is severely scored. This is a link to a picture of my oil pump plate.


10-23-11, 11:55 PM
this scoring can cause a loss in pressure.. But there may also be scoring on the bores for the gears any may need a new oil pump.. I would start with sand the plate down to get it smooth and get all the scoring out.. I would take the pressure valve apart and put some sticky back paper on a flat metal surface and sand it flat.. I would start with maybe a 120 or 150 paper and then finish with maybe a 400 grit... How are the edge of the gears? Are there scraches ? When putting the gears back in back the pump and gears with grease so it will prime and start to pump..

10-31-11, 03:05 PM
I did just that..I took the plate which was scored and some sheets of 320 grit wet or dry sandpaper and wrapped it on a nice size piece of mirror and i went at it. Then I finished it of with some 600. To my surprise it worked and this got rid of all the scoring. The gears are not scratched because i changed them but the housing was scratched. I packed the pump with some vaseline and when I turned it on, I no longer had the oil light on and was getting good pressure. Eventually, I am going to rebuild this engine. The problem with the 390 in my '63 is that the oil pimp housing is part of the front engine cover and the only way of changing the scored pump housing is replacing the whole front cover which is very hard to find. When I rebuild it in the future I will probably try to find a new one.
Thanks Abraham