-Dr REBUILD's Science Lesson . .....

Today's Lesson: Two forms of solid matter cannot occupy the same place at the same time - or simply stated some Corvette vacuum hoses are just way too FAT

Reference: The Corvette Restorer Volume 28, Number 4, Page 44-45

I read with interest a recent article about Headlamp and Wiper Hoses in the Spring 2002 issue of The Corvette Restorer. It noted that a "POPULAR" reproduction hose was included "to demonstrate how much it differs from the original." I emailed the author several times and asked him whose "POPULAR" hoses he was referring too. He declined to provide identification, but I already knew anyway.

Just to be sure he was not referring to the vacuum hoses we market, I re-measured the hoses we reproduced. It is not easy to measure a hose, as it does not remain exactly round, but tends to droop into an oval. Therefore you get a smaller and larger measurement if the hose is not measured in the round state. The early 68-69 hoses we market and the later model larger hoses we market measures within 5 thousandths of an inch of the originals.

DOC'S HOSES: to the left is a picture of a head lamp wiper relay valve with the 3 hoses we market fully installed side by side: Red, Yellow and Green. These are the later style large 70-82 vacuum hoses, not the smaller early 68-69 style which GM changed for fear of collapse. Note: ours have 3 ribs and 1/8" wide stripes.


The main factor in evaluating oversize size hoses is NOT really whether a concours judge will deduct points because of their excessive size. Their main feature is that you cannot install all 3 of the fat oversized hoses on a relay valve. There is only so much space between the 3 staggered vacuum ports on these relay valves. The oversize hose and their excessive wall thickness prevents the 3 hoses from being installed side by side on any GM relay valve.

Brand "Z" HOSES: to the left is a picture of a head lamp wiper relay valve with the 2 hoses fully installed side by side: Yellow and Green. But all three of these hoses are too Fat and there isn't enough room between the top nipple and Yellow hose to install the Red hose - unless you get your razor blade out. Note the "numerous" ribs a 1/4" wide stripes. Looks purdy, doesn't fit and GM never did not put that many ribs on them, stripe them that wide - or make them that fat. Why pay for this; it's even more expensive.

If you purchase this repro from CC, CVS, MAD, Ecklers, and most other middle men - you get the above Brand "Z" repro.

Since 1995 I have been bringing these "other" kits with the oversize hoses to every Corvette Carlisle as a demonstration. I bring 4 different models of their kits with these oversize hoses and challenge anyone to install the third hose. A few people have nearly busted their knuckles trying however. Some tried so hard, I thought they would break the nipple right off the valve. So far no one has been successful.

Please do not ask me to divulge where these four different head lamp and wiper door vacuum hose kits were purchased. Incidentally, some were ordered by our dear old dog. She is now on their mailing list and their catalogs have been very useful for house breaking.


The very first reproduction of these colored vacuum hoses was from a vendor making them for the sixties Camaro's with hidden head lamps. We purchased their hose, prior to have them reproduced ourself. I believe that since 1995 there have only been two different reproductions of these hoses on the market specifically for Corvettes: Mine and these Fat ones. The only way to get their hoses on is to slice away at their OD with a razor blade. You simply must cut away and reduce the wall thickness to install those hoses. However, I don't think that is the original procedure that the General intended.

The main lesson here is to follow this cardinal rule: Don't ever make a Repro from a Repro, because you may have be copied something that is just not the authentic size, shape, etc. Occasionally, these "researchers" have even been duped into copying parts that were never used on any Corvette ever. These "genuine" parts are for fellows whose research consists of purchasing someone else's repro - not hunting down and examining genuine parts. We even duped some into copying three radiator to hood air dams that the General never ever supplied. They copied them and lots of other parts - lock, stock and barrel. They even copied every 68-82 vacuum hose diagram with errors that simply prevent the head lamps from operating. Some Research eh? But I hear they are very polite and in a feature article in one of the Corvette magazines, the owner even bragged about having two full time girls just to handle returns. I wonder why??????? Thankfully, we don't have or need two full time girls to handle returns,

Stay tuned for more Science Lessons. My digital Sony camera is great. As they said: It's a Sony, no Baloney.

UPDATE ~ MAY 22, 2002

On the above date another one of Zip customers gave up and ordered our Headlamp and Wiper Door Vacuum Hose & Tee Kit. For SEVEN YEARS I have been telling everyone that their large hoses were TOO LARGE. Now fellows like this are writing their experiences in chat rooms and discovering the same - the hoses are TOO LARGE.

QUOTE from fellow on the Corvette Forum "I am kind of disappointed in the kit from Zip. This is the first item I bought in the last year of ordering from Zip that just did not work for me. The hose diameters are much larger than the original and the T fitting must be forced into the hose. Way too much effort. I gave up... Search of the archives shows others had the same problem."

Below are the photos this fellow posted on the Corvette Forum.

Zip actually gave this fellow a full refund. But then Zip tried some damage control that is pure Zip double speak. It just pure Zip Style Baloney: a plain ordinary Lie. Zip wrote on the CF "since there are three different size hoses in the kit, possibly the wrong hoses were pulled for the kit."

That is absolute nonsense. The hose that present the biggest problem are the largest hoses - the large Red, large Green and large Yellow stripe hoses. There are no other larger Red, Green or Yellow striped or even un-striped hoses that are used on any year Corvette. Maybe Zip Baloney wagons use them.

The fact is Zip made a Repro from a Repro and never knew it was not original.

What other hoses could they have accidentally put in that kit? None. They put the same hoses that they have been using for the last EIGHT YEARS - since 1995. Did you think they would admit that they have done nothing for EIGHT YEARS or did not know about this problem? If you don't think they have not heard about this - then they must have had their head in the sand for the last seven years, nor paid attention in Federal Court.

The following picture was taken by a customer of Zip to illustrate his original hoses and the larger ones from Zip. He posted it on the Corvette Forum. QUOTE: . "The hose diamaters are much larger than the original and the T fitting". No kidding.


Zips hose on the left and original on the right. Pretty Close eh?

Zips parts are so accurate.

Here's the link to the CF


I couldn't make this up if I tried.