buelldude

So on with the project 72, I have been fixing the things that are the most obvious.
carb
battery
vacuum lines- 600 hundred ft of them
tires
pinion snubber
battery box/jack box/glove box
carpet.


So the big thing that I had question on, the length of the lines that the kit comes with. I have always gone by one rule, the shorter you can make it the better. This kit I have came with lines that are sometimes 10-12" longer than you need???? Is there a madness to the thinking that you need to use those lines at that length because of some engineering bubba made it that way from the factory? Maybe its just the kit comes with extra so you can run it differently? What do you think?

Alan 71

Hi b,
I've not really heard that people are finding that the vacuum hoses are longer than they NEED to be.
I really don't think an engineer specified that a line be longer than needed since Chevrolet watched every dollar that went into producing a car. Generally if they could save even 5 cents on a part they did.
I think the same thing is true for the couple of companies that reproduce hoses… they're not going to give away extra hose.
I can understand a hose being an inch or two long but not really more than that.
So???
Regards,
Alan

7T1vette

To that end.... Do you have a copy of the AIM to know 'how' those lines should be installed? There was a lot of thought and analysis done to determine exactly how those vacuum lines were run. Just connecting new lines to their endpoints without routing them as intended will eventually present problems.

Secondarily... Are you verifying that the line you chose is the correct one for the line you are replacing? If not, there will also be some lines that are way too short.

I'm not intending to find fault--just making you aware that if you have lines that vary much in length from what you are replacing, there is a "problem" somewhere. It could even be that the kit you received was labeled incorrectly for your model year.

GM wasn't worried about a 5 cent difference on part costs. They were worried about fractions of a cent differences!!

buelldude

If I could find a local person that has their car done back to concours quality I could see if they were run the right way. The kit I have is from ecklers and the diagram seems to be right on the money. I don't mind the extra length, it makes it nice to have it if your trying to hide the hose. I put them in one at a time, replacing them accordingly. I'm doing it that way to see if one of them is the issue as to why my lights/wipers are not working right. If I get to the end and find the same results then its time to replace other things. The one thing I would like to find out is the tank connections, are they correct.

Alan 71

Hi B,
Are you asking about the hose connections at the vacuum storage tank behind the left side apron?
If so, here's the Willcox diagram:
One large hose running from the check valve.
One large yellow striped hose running across the firewall from the wiper door relay to a T near the storage tank and then a short hose from the T to the tank
One large yellow striped hose running forward to the headlight relays.
Rather than just starting to buy parts to make the systems work you might consider getting a trouble shooting guide so you can determine what's working and what isn't. It's a LOT cheaper to approach it that way.
Regards,
Alan

DUB

When we all do work on our cars or for me doing it for my customers. We have a philosophy that may differ with what GM did or what others may do.

I myself do not like the hoses to be the shortest possible because I might have to get back into that area...and if the hose...when removed...is now swollen and taken that shape. I want the ability to trim it back so it can seal tightly again. It is not like I have miles of extra hose because I am also concerned that the area looks clean.

I really do not trim too much off the hose kits I use. I can generally get the hoses routed in a way that they do not look all messed up and looking like spaghetti when I am done.

Both Alan and '7T1vette' gave good advice...and I would verify what is wrong with the system...unless you already have done so.

If you need help in that area...we are here to help...or at least I will 'speak' for myself that I can help you if you can not find the answers you need.

DUB

buelldude

So far this site has been great, everyone on this thread has great info. We all have our ways to work on cars and go about it differently but I still go by what my grandfather told me to do. Shut up and listen to what people have to say.


I don't have a way to test the system for problems so I went with the new line kit. I found some of the old lines (not the right size, put together with clamps------) so this was an area that had to be fixed anyway. I'm taking the list (numbered hose) with the hose and replacing it. I see if it fixes the issue and make a note of it. I go to the next and so on. I have found that two of the lines were cracked and it did change the idle. The lights came up a little higher but not all the way. I will get to it little by little.


Who has this trouble shooting guide???? I would like to see how this system works

Alan 71

Hi b,
There are several options for help on the vacuum controlled part of the headlight and wiper
systems.
You can google Corvette Vacuum 101 and you'll a see some very general information about the vacuum system and it's parts.
Mid America sells a Trouble Shooting Guide that's helpful. Various other vendors sell it too.
Dr. Rebuild sells a Vacuum System Guide that shows each component of the systems, describes what each part does, and explains how to test each part to see if it's functioning properly or not. (This guide is what I was referring to when I posted that just buying parts without knowing if they're functioning properly or not gets expensive quickly.
The GM Chassis service manual has good information about each of the systems in the Body/Chassis Electrical Sections… sec. 12-5 for the headlights and sec.12-38 for the wipers.
Good Luck!
Regards,
Alan

There really are no questions that member Dave J can't answer since he truly understands how the systems work.

DUB

I personally do not have any guide out there on the internet...even though they are out there.

But doing this for over 3 decades..I could find your problem(s) in under 5 minutes if the car were at my shop because I know the system (which is quite easy to understand).

If you need to do so. PM me and I can get you my shop phone number and I can talk you through how the system is designed to work and how to easily test it....if all other options have failed and you begin to get frustrated.

DUB