1978 F250 400 vacuum diagram
 

I bought my F250 used and am not sure of the vacuum routing.
Most parts used in this system are obsolete. I'm looking for original vac. diagram and any changes to eliminate these obslolete parts, but still pass emissions. This engine does NOT have an air pump system, no connection to the exhaust manifold. Does have a vacuum amplifier to the EGR and TWO(2) temp controlled vac switches on the thermostate housing.

1978 F250 400 vacuum diagram
 

Check here it shows a 79 400 maybe it is the same.

http://www1.autozone.com/servlet/UiB...3d800ce605.jsp

1978 F250 400 vacuum diagram
 

OR, you could go to the top of this forum & look in a sticky thread titled FAQ's , to figure out which diagram Number you need first.

1978 F250 400 vacuum diagram
 

Post the cal number and we can go from there.

1978 F250 400 vacuum diagram
 

If I am reading his post correctly. It seems like he is looking for a diagram that will eliminate the emissions controls but will still pass emissions testing...

1978 F250 400 vacuum diagram
 

Thanks to Mil1ion and sparkys help I found the cal codes. So to answer Tetaruby, cal code is 7-74-R10, Where DO we go from here? ....Torque1st, I am looking for original vac. diagram for this engine, but also, any help from anyone who ran into the obsolite problem and how they got around it, but still pass emissions.....I'm looking for things like a more up to date vacuum accelerator, or something more modern that will give me the same end result as the old type vac. accel..... Or hook me up with a buddy that might have an old one laying in his junk drawer...anything...HELP

Thanks guys for the help

1978 F250 400 vacuum diagram
 

The only source for those obsolete parts are the junk yards or somebody's junk box. This testing routine is part of the gov't-automaker "conspiracy" to get the old cars off the road and make you buy new ones :D The automakers only made the parts for 5 years and they test for 25+...

1978 F250 400 vacuum diagram
 

Normally there are diagrams here.


http://www1.autozone.com/servlet/UiB...3d800ce605.jsp

1978 F250 400 vacuum diagram
 

I have checked out the autozone vac diagrams in the past and now but no luck, nothing comes close. I purchased a ford factory service manual for my year, guess I'll wait til it gets here and see what new info it has, maybe I can make up my own vac sysem to get me thru emissions.....maybe i should move to an area where they don't test..haha. Thanks for the responces guys. Feel free to e-mail me if anyone comes up with anything that will help.

1978 F250 400 vacuum diagram
 

7-74-R10 is the one I DON'T HAVE :( I have about 10 different prints for the '78 400, but not yours. I do have a California one, but I think it would be too radical to consider from my past experience. I do have the initial release (R0) from '77 if your interested. I can scan and forward it to you. Unfortunately, there's not too much you can disable (other than the EGR) for any kind of performace gains over the stock plumbing. The service manuals are usually useless for emissions specific details.

1978 F250 400 vacuum diagram
 

You can probably go to your local emissions Testing Place to get a diagram of the emissions needed for your truck, Most of the places have it for something to go by. with yours being a F250 it'll have less emissions then the 1/2ton trucks, You might find out less you'll really need that way.

1978 F250 400 vacuum diagram
 

Tetraruby-I'll get back to you on the initial release (R0) from '77 if I can't find the correct one...thanks.

Txquad...that's a good idea but the testing stations around here barely have enough room to stand while your waitting. I haven't seen anything inside resembling a library, not even a pc.

1978 F250 400 vacuum diagram
 

Bobby, did you finally get your vacuum diagram? I have the same ford and same 400 and I cant find a vacuum diagram to save my life. Can you help me out?!? I need to get these damn vacuum lines hooked up. Alaska has damn Emissions and I have to have these hooked up or instant fail!
Thanks
Bob......

1978 F250 400 vacuum diagram
 

Bob, Welcome to FTE!

Did you follow the instructions that are already posted ?

Bobby's will be different than yours

All I need is info about the truck.

Model (F150 ?),Transmission ( A or M),Rear gears, & the Altitude you are at.

1978 F250 400 vacuum diagram
 

I have a 1978 Ford Ranger Supercab, with a 400, 4 spd manual trans, 4wd. The truck is an ALaskan truck, altitude of around 100 ft I beleive. My engine has no cat or air pump and no where to put one. Origonal exhaust is on it and there is no plumbing for emissions.