Cruise Control
Melting Slicks
Joined: May 2015
Posts: 2,365
Likes: 428
From: Cape Girardeau Missouri
They haven't been made in years. When looking for one I found an old post by someone saying he probably found the last "new" (new old stock) one in the world.
The good thing is that many V8 GM cars from the 70s and 80s used a very similar servo. The one I found was NOS intended for a Chevy Nova. The mounting tab at the front was different but all I had to do was shorten the connecting linkage.
The good thing is that many V8 GM cars from the 70s and 80s used a very similar servo. The one I found was NOS intended for a Chevy Nova. The mounting tab at the front was different but all I had to do was shorten the connecting linkage.
Thread Starter
Advanced
Joined: Sep 2017
Posts: 63
Likes: 1
They haven't been made in years. When looking for one I found an old post by someone saying he probably found the last "new" (new old stock) one in the world.
The good thing is that many V8 GM cars from the 70s and 80s used a very similar servo. The one I found was NOS intended for a Chevy Nova. The mounting tab at the front was different but all I had to do was shorten the connecting linkage.
The good thing is that many V8 GM cars from the 70s and 80s used a very similar servo. The one I found was NOS intended for a Chevy Nova. The mounting tab at the front was different but all I had to do was shorten the connecting linkage.
Safety Car
Joined: Oct 2007
Posts: 4,383
Likes: 1,753
From: Seattle Area Washington
If you're looking for a servo that will mount to your current 77 bracket 1977-1978 and some early 1979 corvettes servos had the metal backing and securing nut. Later servos had plastic backs that excepted 2 self tapping style screws for mounting. Completely different brackets. Unless you find a 77 servo you will have to modify the ball and chain setup to connect to your cable. If you find a servo, the 77 service manual says servo must hold 14" of vacuum for one minute, any less is considered defective.
Last edited by bmotojoe; Sep 24, 2017 at 02:22 PM.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
Functionally, about ANY GM cruise vacuum servo will do the work. But, you may need to adapt it for mounting and to rig the connection to your throttle cable. So, get something from that vintage of GM vehicle....it doesn't need to be from a Corvette.
Thread Starter
Advanced
Joined: Sep 2017
Posts: 63
Likes: 1
If you're looking for a servo that will mount to your current 77 bracket 1977-1978 and some early 1979 corvettes servos had the metal backing and securing nut. Later servos had plastic backs that excepted 2 self tapping style screws for mounting. Completely different brackets. Unless you find a 77 servo you will have to modify the ball and chain setup to connect to your cable. If you find a servo, the 77 service manual says servo must hold 14" of vacuum for one minute, any less is considered defective.
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Safety Car
Joined: Oct 2007
Posts: 4,383
Likes: 1,753
From: Seattle Area Washington
Len,
The 1977 model servo mounting bracket is located along the driver's side inner fender forward a little of the steering gearbox, your 1978 servo brackets are bolted to your intake and head. Here is a link to a forum members Late 1979-1981 brackets and servo. This setup will work on the 78 but not correct. Anytime you inquire about a used servo make sure it will hold a vacuum as described above.
https://www.corvetteforum.com/forums...g-bracket.html
The 1977 model servo mounting bracket is located along the driver's side inner fender forward a little of the steering gearbox, your 1978 servo brackets are bolted to your intake and head. Here is a link to a forum members Late 1979-1981 brackets and servo. This setup will work on the 78 but not correct. Anytime you inquire about a used servo make sure it will hold a vacuum as described above.
https://www.corvetteforum.com/forums...g-bracket.html
Burning Brakes
Joined: Jul 2017
Posts: 1,114
Likes: 149
From: Frisco TX
Len,
The 1977 model servo mounting bracket is located along the driver's side inner fender forward a little of the steering gearbox, your 1978 servo brackets are bolted to your intake and head. Here is a link to a forum members Late 1979-1981 brackets and servo. This setup will work on the 78 but not correct. Anytime you inquire about a used servo make sure it will hold a vacuum as described above.
https://www.corvetteforum.com/forums...g-bracket.html
The 1977 model servo mounting bracket is located along the driver's side inner fender forward a little of the steering gearbox, your 1978 servo brackets are bolted to your intake and head. Here is a link to a forum members Late 1979-1981 brackets and servo. This setup will work on the 78 but not correct. Anytime you inquire about a used servo make sure it will hold a vacuum as described above.
https://www.corvetteforum.com/forums...g-bracket.html