1956 -1957-1958 Cadillac vacuum check valve ???????

[Bill Balkie 24172]

This is the vacuum check valve that screws into the right side of the engine block by the starter. Are these valves available, and if so  where can i purchase one . i once had a problem where i was sucking oil into the intake , Because of a faulty valve . I would like to have one for a spare . Thanks Bill

[David King (kz78hy)]

Bill

Those are not difficult to repair.  I did not know to fix mine while the engine was out and had to remove it on the car.  It is a lot harder that way, at least on the Brougham.  The oil filter and oil pressure sending unit obstruct the access to it.



Once you have it out, it comes apart easy.  Just clean it and keep the parts in the original orientation.  The spring in there is very weak and will  probably be ruined.  I went to the hardware store and bought some light Stainless steel wire (like .020" or so) and a 3/8 dowel rod and wound the wire around the dowel to make a new spring, counting the number of coils on the original.  It does not take much force to close the metal disc so you can play with the new spring to get it where you want it.

When you have it reassembled, suck on the end that screws into the pipe to ensure there is no air coming through.  If it does, then the disc is not seating correctly and the check is not working.

Here are some shots of mine.







David

[Bill Balkie 24172]

David, Thank you so much for the detailed photos ,A picture is worth a thousand words . i Guess the only thing that can go wrong with this check valve is the spring. I am a toolmaker by trade so the spring .020 is no problem .When mine went bad i was burning so much oil i thought the car was on fire .One more question what is the actual function of this valve . Again thanks  so Much 

Bill

Those are not difficult to repair.  I did not know to fix mine while the engine was out and had to remove it on the car.  It is a lot harder that way, at least on the Brougham.  The oil filter and oil pressure sending unit obstruct the access to it.



Once you have it out, it comes apart easy.  Just clean it and keep the parts in the original orientation.  The spring in there is very weak and will  probably be ruined.  I went to the hardware store and bought some light Stainless steel wire (like .020" or so) and a 3/8 dowel rod and wound the wire around the dowel to make a new spring, counting the number of coils on the original.  It does not take much force to close the metal disc so you can play with the new spring to get it where you want it.

When you have it reassembled, suck on the end that screws into the pipe to ensure there is no air coming through.  If it does, then the disc is not seating correctly and the check is not working.

Here are some shots of mine.







David

[David King (kz78hy)]

One more question what is the actual function of this valve .

Bill

You answered your own question.  The check valve is to keep oil from being drawn up from the oil pump.  This is especially bad when the vacuum pump has failed on the oil pump since it is not providing any vacuum, so the engine vacuum pulls the oil up like a kid drinking soda through a straw.

My rebuilt pump/vacuum is not working, so I had the same problem.  I was in the garage today cleaning up a mess and saw my pull off oil/vacuum pump on the bench and took it apart.  It was locked up pretty good.  I think the case for the vacuum portion will clean up and could be reused some day.  I think I will get this pump rebuilt and reinstall back to the car someday.  I first have to get a job, though, no money for toys right now. 

David

[Frank Puma]

David,
Very nice detailed pictures of the vacuum check valve. On the picture of the assembly apart on the brass fitting on the right, there should be a strainer that looks like a screen at the bottom of the large opening where it reduces to the pipe size. From the one picture you have it looks like it is missing. I just sold one of these assemblies on eBay. eBay number 380193237043. If you go to 1958 Cadillac on eBay motors search and click on sold items it will come up and you can see the pictures posted. One has a good shot of the strainer. Thanx Frank Puma CLC #10721

[David King (kz78hy)]

Hi Frank

You are correct, the screen in that one was bad.  The unit shown was one I pulled from EB 494, which is a parts car.  While Morgan Murphy was on his drive across the county in EB 702 he spent some time at my garage fixing some odds and ends that were bothering him on the trip.  During a check of his car, we noticed that this check valve and pipe were missing from his car.  He was running with an open vacuum hole in the engine, and as it turns out, his vacuum pump worked.  So, I offered him a loaner off one of my parts cars.  It was pretty cool to have 4 58 Broughams sided by side in a large 3 car garage.  So I walked over 2 cars and pulled off the valve and pipe.  Now that sounds easy, but those are difficult to access with the starter, oil filter, and oil pressure sending unit in the way.  After an hour or so of frustrating labor on our backs and several choice words, the parts were freed from the car. 

Those photos were done while we rebuilt that unit and it was decided to forgo the screen there.  The one in my driver (615) was intact as was the spring, so I'm good for now.  To bad my vacuum pump does not work and the line is plugged.

Great eye and thanks for the info, others will no doubt benefit from that.

David

[abob5]

If some of my fellow members do not have a check valve at all which I had when I got my Cadillac. You can find them in McMaster Carr they are bigger is size so I just had to relocate mine a little father up the firewall just get the one that has the least amount of vacuum to open. HTH Bob

[Bill Balkie 24172]

Thanks Bob , I buy from that company almost daily . I will check it out . Thanks again for all of your input .. Bill

If some of my fellow members do not have a check valve at all which I had when I got my Cadillac. You can find them in McMaster Carr they are bigger is size so I just had to relocate mine a little father up the firewall just get the one that has the least amount of vacuum to open. HTH Bob

[Bob Kielar]

Hi Bill
          I found my invoice from McMaster Carr the part number is 7775K51 with shipping the cost is $17.73. HTH Bob

[Bill Balkie 24172]

Thanks Bob  , The new price is 13.48 ... Does the original valve screw right into the block ? And to use this one i would have to plum an extention because of a clearance issue .  Again , i do not need one ,but would like to be prepared just in case . Bill

Hi Bill
          I found my invoice from McMaster Carr the part number is 7775K51 with shipping the cost is $17.73. HTH Bob

[Bob Kielar]

I DID NOT HAVE ROOM TO PUT IT RIGHT INTO THE BLOCK. I HAD TO RUN A PIECE OF COPPER TUBING FORM MY BLOCK TO THE CHECK VALVE. I HAVE A 55 MAYBE YOU HAVE MORE ROOM IN YOUR CADILLAC. HTH BOB