Vacuum Problem
Thread Starter
Safety Car
Joined: Mar 2005
Posts: 4,255
Likes: 82
From: Brampton Ont.
Vacuum Problem
Can I ask a favour to the 75 Vette owners on the forum to PLEASE post pictures of your engine without the air cleaner on. I need to identify where all the vacuum lines are going, so that I can put mine back together again. I have a major vacuum leak and just put a rebuilt carb on a couple of days ago thinking that would solve the problem, but the leak is still there. I tried disconnection most of the lines and plugged them up but I still can't get the engine to idle lower than about 1100 rpm. I would really appreciate your help, as I have been stuggling with this motor for about 4 months and have spend to many hours trying to figure this out.
Thanks again
Frank
Thanks again
Frank
Last edited by Maymyvetteliveforevr; Jul 3, 2005 at 05:57 PM.
Instructor
Joined: Apr 1999
Posts: 172
Likes: 17
From: Canada
Try this site:
www.corvettefaq.com
Search under "vacuum systems" and you may find some info. that will help.
Good luck.
www.corvettefaq.com
Search under "vacuum systems" and you may find some info. that will help.
Good luck.
Thread Starter
Safety Car
Joined: Mar 2005
Posts: 4,255
Likes: 82
From: Brampton Ont.
Thanks for the info dkw. I tried FAQ already and was unable to find the information needed. What I did was go to search and typed in Vacuum and opened every possible link.
To be more specific re my request I have a 75, 350 L48 with no air. I'm still hoping some one can help.
To get it on the road I need
1. The engine running properly
2. Complete exhaust ( Existing has to many holes )
3. Redye interior but not necessary
4. Cosmetic exterior trim I can't locate.
To be more specific re my request I have a 75, 350 L48 with no air. I'm still hoping some one can help.
To get it on the road I need
1. The engine running properly
2. Complete exhaust ( Existing has to many holes )
3. Redye interior but not necessary
4. Cosmetic exterior trim I can't locate.
Instructor
Joined: Apr 1999
Posts: 172
Likes: 17
From: Canada
I was looking in a "Dr. Rebuild" catalog and they show pictures of vacuum systems for various years including a 75 L-48. It's not big, approx 3x3, but it does show where everything goes. If you want I will cut it out and send it to you by ordinary mail (I don't have the equipement to send it any other way). If you want to pm or e-mail your address I will send it out right away.
As far as parts are concerned have you tried all the local sources?
If you want a couple of fairly local U.S. sources I have used let me know.
As far as parts are concerned have you tried all the local sources?
If you want a couple of fairly local U.S. sources I have used let me know.
Thread Starter
Safety Car
Joined: Mar 2005
Posts: 4,255
Likes: 82
From: Brampton Ont.
This is what I'm up against, I removed the air pump, and the thermostat housing (which had one line in and one line coming out). By the way I had to get my son to not only take these pic. but post them, and he's only 15, don't I look bad. At this point I believe every vacuum line is plugged. 
Thread Starter
Safety Car
Joined: Mar 2005
Posts: 4,255
Likes: 82
From: Brampton Ont.
dkw, I would hate for you to cut out a page out of a catalog that you may need one day, instead with the help of the pictures below can you make sense of the vacuum lines and maybe I can put them back one at a time.
I have to go out of town tomorrow and will be back Friday night. You can bet that the Forum will be one of this first things I look at when I get home. Oh ya after I kiss my wife and kids, can't forget them.
Thanks
Frank
I have to go out of town tomorrow and will be back Friday night. You can bet that the Forum will be one of this first things I look at when I get home. Oh ya after I kiss my wife and kids, can't forget them.
Thanks
Frank
Instructor
Joined: Apr 1999
Posts: 172
Likes: 17
From: Canada
There are 10 hose lines plus one "T" fitting listed for a 1975 so it would be kind of hard to explain where they all go.
Also, from your pictures and the one I'm referencing there are a couple of things I can see.
You have headers and the picture I have shows hoses from a canister (I believe from the heat riser on the manifold) to a valve on the thermostat housing - which your housing does not have.
Without these your probably are still going to have some vacuum ports open???
I don't ming cutting the picture out and sending it to you, then you can have a look yourself. You can always send it back if you want.
Also, from your pictures and the one I'm referencing there are a couple of things I can see.
You have headers and the picture I have shows hoses from a canister (I believe from the heat riser on the manifold) to a valve on the thermostat housing - which your housing does not have.
Without these your probably are still going to have some vacuum ports open???
I don't ming cutting the picture out and sending it to you, then you can have a look yourself. You can always send it back if you want.
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