VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1912-1928 vacumm tank tubing

In most of the picture's and setup's of the 28 engine, I notice that the vacumm tank line coming off the top of the intake manifold to the tank has a loop in the copper tubing? is there a reason for that? and if so, what purpose does it serve ??? and is it necessary ? thank you in advance.

Hi n j horst,

The purpose of the loop in the line is to reduce the damage done by vibration. Although the movement between the engine and vacuum tank is slight, the constant vibrations would eventually loosen the connections if the line were taut.

Mr Ray: thank you so very much in taking the time you do to help us all, It is most appreciated by myself and i believe from everybody that seek's the knowledge we need in restoring and preserving the early chevy's ! you are quite a gentalman!!!!

N.J. I knew there was a reason that Goodyear invented rubber fuel hoses!

Hi guys was the loop standard on tubing to the vacume tank ?I have a number of books that don't show the loop 1928 sales data ,and the new features for the bigger and better chevrolet perhaps Ray or Mr Mack I could send you a scan and you could post them.

Have completed a partial survey of my library and find a few pictures that will answer the vacuum line question. As they are all basically the same, I have chosen to post the page from my 1928 Dealer’s Album (Chevrolet Sales Data Book). This is page 41-Album 1-1-28. As this shows the 1928 vacuum tank, which is unique to the 1928, it can be assumed this is not a ”˜carry over picture’ and is accurate for the 1928. For clarification this picture is from a closed car. Note the smaller vacuum line that enters the firewall and goes to the windshield wiper. This connection does not exist on the open cars.

This should put to rest the configuration of the 1928 vacuum line from the manifold to the vacuum tank.

Now for the $ 64k question were the fuel lines originally: brass, copper, steel or ? I will give my answer later.

Thanks Ray you are a mountain of knowledge

A question arising from the supplied pictures..... Is that the correct angle for the air cleaner? Mine is mounted vertically.
Tim.

The Capitol series (AA){1927} mounts vertically and the National series (AB){1928} mounts horizontally.

Tim
The Australian 28's had a different manifold than the US 28's. This was a reslult of the steering column (RHD) not fitting with the US manifold. The US manifold goes between the steering column and the engine. The RHD maninifold goes around the outside of the steering column.
The air cleaner sits vertical on Aus. cars and horizontal on US cars. I have a US 28 2 door sedan and an Aus. tourer, and I used to make exact copy reproduction exhaust systems for all model Chev 4's
Hope this helps
Chris

lot's of great information! now would the current tubing(cooper) that has a 1/4 dia. outside measurement be correct? as found at home depot & hardware store's?, or have some of you had better result's with other dia. if so would you please list inside and outside dia. for us and in fact would you use copper or other material? thank's everyone.

I'm trying to plumb my restored fuel pump. The line from the manifold to the "T" on top of the pump looks like it should be 5/16" because of the size of the nut that goes on the "T". The copper tubing I purchased is too big to go inside the fitting but the nut fits fine. Do I use smaller tubing and find a special nut? If so where do I purchase what I need.
Thanks again for all your help.
Mike
P.S. Some of the old posts the pictures appear as a red "X". Is there a way to reload these?

Hi, The instruction sheet furnished with your rebuilt vacuum tank is a copy of the picture that is denoted as the dreaded red X.

The RED X has now been replaced with a picture.

Thanks Ray
The picture provided has been a big help, but I still can't figure out the tubing and brass nut.
The picture makes the nut on one side of the "T" look bigger but the line looks the same size on both sides.
The picture on this post reminded me of some other posts with the same problem. I have found many older posts by you that are very informative about 1928 cars but some of the pictures don't display. I hoped there was something I could do to view them with out troubling someone else.
Mike

Mike B,

The Vacuum fuel pump Vacuum feed line from the inlet manifold on a 1928 is 1/4 inch outside diameter. If you still have the original brass T on the vacuum fuel pump, a 5/16 OD tubing will not fit into the fitting. The confusion on this issue comes from the fact that a modern 5/16" tubing compression fitting will screw onto the original fitting, has a 9/16 inch hex like the original, but has a 5/16" diameter hole for the tubing. The original tubing compression fitting has a 9/16" hex, but incorporated a 1/4" diameter hole at the tubing entry location. (A modern 1/4" tubing compression nut has a 1/2" hex.) Same logic holds true for the windshield wiper port on the original vacuum tee where a 3/16" OD tubing was used. A modern 1/4" OD tubing compression nut
uses a 1/2 hex and can be installed, but it will have a 1/4" hole where the original 3/16" tubing compression nut has a 1/2" hex, but a 3/16" hole for the tubing.

Oldie
It sounds like I need a 9/16" hex nut for 1/4" tubing. Where do I find this fitting? Maybe I'm looking in the wrong places.
Thanks
Mike

If you are not going for the high point car, get on your bicycle and peddle on down to your neighborhood True Value Hardware store and purchase a modern brass "T" fitting and associated crush rings and nuts.

If you are going for all the points in judging then you better use brass line instead of copper or steel.

Is brass more brittle than copper; could that cause a problem or not?

I get the correct size copper and steel tubing and connections for automotive vacuum and fuel lines at a good auto supply store, some of the smaller NAPA stores have to order it on overnight delivery. I have yet to find an affordable supply of brass tubing. buy steel and powder coat it brass colored, or plate it, what the heck, it is only money....Isn't it?.

Yes, brass is more brittle than copper and more prone to vibration cracking than steel. That is likely the reason that brass was replaced with steel in ca 1930.

I had no success finding a "T" or the proper nut. So I took a 5/16 ferrul and ground it in half. This centered the smaller ferrul in the nut and alowed me to connect it. This won't pass inspection for judging but allows me to drive the car until the Portland Swap Meet where I hope to find the proper part. Thanks again for all your help.