Vacuum Diagrams, Documents, and Service Manuals

Dakota Kid

New member
Hey all,
so I'm the newest guy on the block but I've got a pretty quick question for the masses, and couldn't find previous posts related to it.

First off, I have a '73 Scout II with a 345 (I believe), auto tranny. At some point in this 'ol girl's sordid life someone hacked up the vacuum lines pretty badly. Despite lots of miles, being cold-blooded, and signs of very poor maintenance I got upwards of 18 mpg on a recent road trip from mt to ok, so it's got me thinking. The diagram on the air cleaner is all but gone, so I was wondering if anyone had access to a pdf of the vacuum system on this engine. I don't have an extra $100 or so for a full service manual, but if anyone has the entire thing that would be amazing too. Thanks in advance from an active duty air force member in oklahoma.
 
Welcome to the forum dk!

And up front...thank you for serving our country!

I've attached a partial scan from the m/y 1973 "introduction" service letter sent to all ihc motor vehicle dealers dated aug. 14, 1972 (service letter slf72-41). This training document explained in detail all the changes in engine and emissions systems for the m/y 1973 rated under 6,000lbs. Gvwr.

This is the pair of vacuum diagrams that you have asked about. These are good for either 304 and 345 2v applications, witha sub-section for the 392 4v app. The 392 engine was not an oem item for the Scout II platform.

This should provide what ya need. If it turns out your rig is "earlier" or "later" or really po-scruud, then we'll need good pics of your engine bay to help ya work out the plumbing.

If you have more questions or need help with this, please post in the "carb tech" sub-forum so we can try and keep all the common schnizz together. You will also finds tons of related info in that forum along with many others. Your carburetor should be one of the "22xx" series mixers, you'll see those are a major topic in the carb tech section!
 

Attachments

  • 1973 SV Vacuum Diagram.PDF
    3.7 MB · Views: 3,212
I take it your missing the decal on the cowling. Sometimes they have been painted over.

Here what they look like, this is from a 1976 Scout traveller

attachment.php


attachment.php
 
Last edited:
You guys are the greatest, thanks for the info. I'll dive into it this weekend and see what I can see. Sorry for the posting shenanagins, I'm a certified meathead. Cheers.
 
Hey ! Started reading that pdf. Of the service letter pertaining to the vacuum system, this would really help me to map out the vacuum system of my 1973 258.

If there's more of the publication that you could post on here.

The info in that letter is wicked :icon_up:
 
See your other post, you now have the diagram available for the 258. Sorry for the delay, I've been without a computer for several days now and I'm still barely able to get back in the loop.
 
I have a 1973 Scout II that I am trying to do the vacuum lines on. I do see similarities with the one you posted, but the ports off of the carburetor are different. I only have 1 vacuum port off of the mounting plate at the front. It is a closed top carburetor. Would you happen to have a diagram that would match this configuration?
 
I have a 1973 Scout II that I am trying to do the vacuum lines on. I do see similarities with the one you posted, but the ports off of the carburetor are different. I only have 1 vacuum port off of the mounting plate at the front. It is a closed top carburetor. Would you happen to have a diagram that would match this configuration?

What engine do you have? That PDF file pertains to model year 1973 Scout II having SV8 engines (304 or 345) and factory original Holley 2210 2bbl carb. If any aftermarket equipment is in place on your engine, that would certainly change the equation. I don't know what you meant by "closed top" carb. Please post pics of your engine with air filter housing out of the way if you don't know what you're looking at.
 
I do have IH original service manuals. I forget the exact catalog number. The bih red ones ya know if you seen one before and if you happen do find one. Grab it if possiblile! I have 4 thanks to my grandpa...and specifics of info perhaps anybody needs I'll try to support.
 
Does this diagram also work for a 1973 1110 with a 304 engine? I'm having difficulty reading the one on my air cleaner and would like to reference this. Also I noticed both reference an air pump. What does that part look like as I don't see it in my engine compartment.
 
I’m also working on the vacuum lines on a 1210 with a 304, is this black tank part of emissions control?
image.jpg
 
That is a vacuum storage canister for your HVAC system. The purpose is to provide enough sufficient, steady vacuum to actuate the various blend flappers in the system during low manifold vacuum situations such as heavy acceleration.
 
There should be two hoses. One between the canister and an intake manifold fitting and the other going through the firewall into the cabin and connecting to the distribution port on the HVAC. Without both connections being made, there will be a vacuum leak when the engine is running.
 
Thanks, I will address that next, the Rewire went well, long overdue, but the alternator is only supplying 12.2 volts, could it be loose belts, slight change up to 12.4 when revved up.
 
Back
Top