Author Topic: Vacuum hose cluster bomb 1985 c10 silverado  (Read 27035 times)

Offline fragmental

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Vacuum hose cluster bomb 1985 c10 silverado
« on: August 11, 2012, 11:20:09 PM »
I'm working on a 1985 chevrolet...I thought it was a silverado, but just read that silverado is a trim designation for this year.  It's probably a c10.  I know it has a 305. 

The engine was rebuilt over a year ago and the guy who put it in made a mess of all the other parts.  I think he he considered anything that wasn't part of the engine unnecessary.  Right now I'm just trying to get all the vacuum hoses routed correctly but I know very little about the vacuum system.  I'm not a mechanic. My knowledge is limited and what I do know is mostly for the 92 jeep and 84 toyota that I ocassionally work on.

The vehicle emission label is missing.  I think I've found the right vacuum diagram but I'm not sure.


I spent all of this afternoon trying to identify everything in the diagram.  I think some things may be missing.  I've identified most things but there are still some things I'm unsure of. 

1. The only thing that should not be put back in the vehicle, as far as I know, is the smog pump.   From this diagram that looks to me like only 1 hose being plugged, yet I think the "dvtvr vlv" has 3 hose ports on it.

2.  What I think I've identified as the manifold vacuum source looks like it has 3 hose ports on it.

3. What is this? (Edit)  I'm fairly certain this is the "egr bleed sol" on the diagram.  It may also be called an egr vacuum solenoid.

I have more pictures of this if needed for identification.


I have a lot more questions, but the truck is not with me and I think this is enough for now. 
« Last Edit: August 13, 2012, 03:06:07 AM by fragmental »

Offline 1980c10

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Re: Vacuum hose cluster bomb 1985 c10 silverado
« Reply #1 on: August 12, 2012, 10:19:43 PM »
You really don't need a lot of that stuff for the truck to run good. If the truck runs good now; you may want to leave it alone. reinstalling everything back to stock may require a new tune and more work. Also if these parts sat idle for years some of then may not work anyway.
Ultimately consider your goals with the truck and engine and go from there.

Offline fragmental

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Re: Vacuum hose cluster bomb 1985 c10 silverado
« Reply #2 on: August 13, 2012, 01:56:23 AM »
I need it to run well and efficiently, and also for the cruise control to work.  The cruise control worked before the engine overhaul.

Offline 1980c10

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Re: Vacuum hose cluster bomb 1985 c10 silverado
« Reply #3 on: August 13, 2012, 02:34:40 PM »
I need it to run well and efficiently, and also for the cruise control to work.
I am assuming this is all you want, that you aren't looking to keep it 100% stock and dont need it to pass inspection.
its easier to let you know what you need rather than what to scrap;
-connect you vacuum adv. to carb vacuum source.
-manifold source to brake booster.
-pcv to vacuum.
-trans, vacuum modulator to vacuum.
-I'm not familiar with a vacuum cruise set up.
Hopefully I rembered everything and If I didn't hopefully someone will chime in and also give some cruise info.
After doing this You'll need to cap any open vacuum sources, adjust your timing and possibly readjust the carb.
I have done this with three of these trucks and it has made everyone of them run great and get nice fuel mileage.
Also make sure your choke is operating properly.
Hope this helps and if you need any more direction just post back and be specific as you can with your questions.

Offline fragmental

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Re: Vacuum hose cluster bomb 1985 c10 silverado
« Reply #4 on: August 17, 2012, 09:10:12 PM »
I don't need the decel valve, efe, egr&solenoid, charcoal canister, or thermostatic vacuum switch?

Also, there are 6 vacuum ports on the carb.

Offline fragmental

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Re: Vacuum hose cluster bomb 1985 c10 silverado
« Reply #5 on: August 17, 2012, 11:52:46 PM »
Did I mention it has the stock carb?  Apparently there was a holly for it but it didn't fit or it was stolen or something.

Also, I might need some help identifying what the parts I need to hook up actually look like and where they are.