wilpetty
1/2 ton status
I have a question...Are vacuum lines essential? I have 75% of mine capped off. Is this anything to worry about? Most of my lines are cracked or cut...Anywhere where I could get a new set or should I just let it be?
CK5
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Vacuum Lines!!!
- Thread starter wilpetty
- Start date
454Sub
5/8 ton status
Well that depends, they are essential for emissions. Your dizzy also uses one for advancing spark. And your charcoal canister uses one to burn vapors so you dont smell them. With no emissions, you only need the one for the dizzy. I like the charcoal canister as it makes the truck not smell like gas fumes, or the garage for that matter, as I am not fond of the smell.
wilpetty
1/2 ton status
Any pic of the line and the charcoal canister? I def. smell alot of fumes
Vac line costs like $3 for 5 feet at any auto zone. If its cracked, replace.
You should have one going from carb to advance on the dizzy.
Then I beleive cruise control takes vac.... if you have it.
Your charcoal canister yes, but most seem to always be disconnected anyway.
Im sure theres a couple more I can think of.
You should have one going from carb to advance on the dizzy.
Then I beleive cruise control takes vac.... if you have it.
Your charcoal canister yes, but most seem to always be disconnected anyway.
Im sure theres a couple more I can think of.
I'd say EGR, vacuum advance, TCC (if 700R4), and EVAP are the only ones "needed". Thermac is one for those who have issues with cold ambient temperatures. Unfortunately most vacuum tubing is tied together in one way or another, such as with thermal vacuum switches.
EGR (and Thermac maybe) is the only one you don't really have to have, but without adjusting the carb, I had an issue with a lean surge at light throttle/low speed cruise when I disabled it.
Trading a mess of hoses, for a mess of wiring (TBI or other EFI) is an option.
Edit: 454 got two I missed, if AC blend doors, and if cruise control, that too.
He's thinking ported and manifold vacuum.
Edit Edit: who needs vacuum booster?? Cut it and cap baby! lol
EGR (and Thermac maybe) is the only one you don't really have to have, but without adjusting the carb, I had an issue with a lean surge at light throttle/low speed cruise when I disabled it.
Trading a mess of hoses, for a mess of wiring (TBI or other EFI) is an option.
Edit: 454 got two I missed, if AC blend doors, and if cruise control, that too.
He's thinking ported and manifold vacuum.
Edit Edit: who needs vacuum booster?? Cut it and cap baby! lol
Last edited:
454Sub
5/8 ton status
Ok, first if any of them leak, and they are tied into the intake/carb/anything drawing vac out of the engine directly, it will cause problems. Lean conditions = kaplow! = engine disaster = 
= 
I dont have any pics, as I cant post them, and I have TBI. But if your lucky, on your radiator support, there should (sometimes, if lucky) be a sticker that displays where all the lines are supposed to run. Most of them are for emissions and all that other nonsense, so if you dont have to pass them, your cherry in that aspect. Also, most Haynes/Chiltons have this diagram, and it is easily searchable with the Godly Google.
The canister has a line that runs to the gas tank, and one vent (it is bigger than the rest), and one that runs to the carb. (what carb do you have btw) The top of the canister should be marked somehow, some way. I would go check, but its like 15* outside, so thats out of the question.
Then the dizzy has a line that also runs to the carb.
Remember, there are 2 types of vacuum an engine produces. One has high vacuum at idle, and it drops as RPM increases, and obviously, the other has low vac at idle, and it raises as RPM increases. The latter is only on certain ports on the carb. The former is intake vacuum. I cant remember the correct names for the two anymore.
Edit. Ac blend doors and cruise control also use vacuum.
= I dont have any pics, as I cant post them, and I have TBI. But if your lucky, on your radiator support, there should (sometimes, if lucky) be a sticker that displays where all the lines are supposed to run. Most of them are for emissions and all that other nonsense, so if you dont have to pass them, your cherry in that aspect. Also, most Haynes/Chiltons have this diagram, and it is easily searchable with the Godly Google.
The canister has a line that runs to the gas tank, and one vent (it is bigger than the rest), and one that runs to the carb. (what carb do you have btw) The top of the canister should be marked somehow, some way. I would go check, but its like 15* outside, so thats out of the question.
Then the dizzy has a line that also runs to the carb.
Remember, there are 2 types of vacuum an engine produces. One has high vacuum at idle, and it drops as RPM increases, and obviously, the other has low vac at idle, and it raises as RPM increases. The latter is only on certain ports on the carb. The former is intake vacuum. I cant remember the correct names for the two anymore.
Edit. Ac blend doors and cruise control also use vacuum.
Here is the sticker off of my 86 Cali emissions burb.
Definitely check the vacuum line for the converter lockup, which runs near the brake booster. Issues with that can give you transmission problems.
buy a variety of vac hose and start replacing one at a time..
and always watch out for flaming nuns being launched from your windows like mortar pods...
and always watch out for flaming nuns being launched from your windows like mortar pods...
I'd ensure the PCV valve is hooked up,otherwise you could blow seals and cause oil leaks,and the oil will sludge up badly eventually and could cause engine damage after awhile...the brake booster and spark advance and tranny modulator if it needs one,is important too...
wilpetty
1/2 ton status
Yes all good to know! I do have the diagram on the front so it is pretty easy to see what is going on...I plan on replacing all of the ones possible
