Vacuum hose installation for 1970

[Kenneth H.]

Forgive me if this is a dumb question, but I want to make sure that I do it right the first time. I recently purchased a set of vacuum hoses from Dr. Rebuild and am going to install them this weekend. Before I install, I was wondering if there is a correct orientation of the colored stripes on the hoses (i.e. facing up, not visible, etc.), or were they installed with no particular orientation? I didn't see anything in the judging guide, but I may have missed it.

Thanks.

[Terry M.]

Re: Vacuum hose installation for 1970

No particular orientation to the vacuum hoses Ken. The sole purpose of the color stripe is to identify which hose connects to which port. During the early part of 1970 model year there were colored marks on the vacuum parts to aid the installers, but during the model year they must have become more proficient because the color indicators went away.

Also during the 1970 model year the filament tape used to secure some vacuum hoses went away. I believe, but have no proof, that they began to use rubber cement at the vacuum connections and the need for the filament tape was thus reduced.

Sorry, I hope you didn't expect a simple answer.

[Kenneth H.]

Re: Vacuum hose installation for 1970

Terry, thanks for the response and additional info. I really appreciate your help. I have an early '70 (Feb 5) and was wondering which vacuum parts had the color markings, and what those markings looked like. I'm certain that at some time in the past the vacuum system on my '70 was replaced with reproduction parts and there's no sign of any markings. Also, since you mentioned it, I was wondering how the filament tape and rubber cement was used on the early '70 vacuum systems. Any additional help would be appreciated.

Thanks.

[Terry M.]

Re: Vacuum hose installation for 1970

You don't ask simple questions, do you?
I am past due packing and getting some shut eye for the trip to Iowa. Once there my time on this board will be minimal. You might have to wait until I get back on Monday, and I can answer from work.

Of course I am not the possesor of ALL the 1970 vacuum information int he world. Maybe someone wants to work at it.

[Kenneth H.]

Re: Vacuum hose installation for 1970

Terry, I can wait until you get back. In the mean time, like you said, maybe someone else might have some thoughts.

Thanks.

[Terry M.]

Re: Vacuum hose installation for 1970

Your car is early enough for all he filament tape, colors and dates on the headlight actuators -- so go for it.

The valves had red, yellow and green dots of paint by the large ports.Headlight actuators had red Dychem on the top, and green on the bottom. Don't use red Magic Marker -- it looks like crap. Use Dychem markers from Fastenal. I am not sure, but there may be paint colors on the controls under the dash too, but others can help with those.

Once you are sure you have the hoses int he right places and the system works perfectly you can glue the hoses to the nipples with rubber cement, but your car is too early for that from the factory.

Filament tape goes around the filter, the check valve, and some of the T connections. The one fight by the driver's side fender drain channel is shown in a picture I posted about the rivet used to hold on the harness bracket at that point.

There are also some pictures of my engine compartment (January 29 build date) in the archives that should give you some ideas. Thanks to the restrictions on this site, I can't post them again -- so you have to learn to search -- there are no short cuts. If you can find them you can duplicate the vacuum system. That ought to save you about five years of research at Corvette meets around the country.

It's past my bedtime. I'll be cranky tomorrow, and I'll never shake my sinus infection.

[Kenneth H.]

Re: Vacuum hose installation for 1970

Terry, thanks for taking the time to give me the info before you left on your trip. Interestingly, whenever you post a picture I save it to my computer and rename it starting with "Terry...". I do this because I know that you have an "original" 'vette and I can use those pictures whenever I'm trying to get something back to what it was at the time of manufacture.

I don't know why I didn't check my picture library before posting. I have numerous pictures of your engine bay, including some pictures of the vacuum hoses and connections that we're discussing. I can plainly see the tape as well as some of the paint markings. I'll use these pics when I install the vacuum lines.

Thanks for all of your help.

[Alan S.]

Re: Vacuum hose installation for 1970

Hi Ken,
Reading Terry's reply about the under-dash vacuum components made me take a look at my notes.
My 71's headlight-door and wiper-door vacuum overides have a blue dab (quite thick and bright) at the bottom (plunger end) and a messy white dab at the top.
What's curious is that only the headlight-door overide gets a blue (and a white) striped hose. The wiper door-overide gets a white stripe hose at the blue dot and an all black hose at the white dot.
I think the dots can only be seen during judging with a good mirror and an agile back.
Regards,
Alan

[Kenneth H.]

Re: Vacuum hose installation for 1970

Alan, thanks for the info. I don't think that my under dash components have been restored so I'll take a look this weekend to see what mine looks like. I'll let you know what I discover on Monday.

Thanks.