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leaky hvac controller

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Old May 6, 2018 | 03:26 AM
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wishitwascamaro's Avatar
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Default leaky hvac controller

My 85 corvette has the vacume operated hvac control head and it leaks. this causes a manifold vacume leak and also causes problems with the cruise control since it is on the same vac reservoir any place to get repair parts or to get an overhauled unit?
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Old May 6, 2018 | 09:07 AM
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Originally Posted by wishitwascamaro
My 85 corvette has the vacume operated hvac control head and it leaks. this causes a manifold vacume leak and also causes problems with the cruise control since it is on the same vac reservoir any place to get repair parts or to get an overhauled unit?
have you actually identified the cause of the vacuum leak? there is a two-way check valve, a small round accumulator, and a bunch of vacuum hose that adds to the system. if it is indeed the AC head unit, there are actually two "select manifolds" on the head unit. is it the manifolds, or the vacuum couplers or hoses that attach to the manifolds? as far as I know, repair parts are not available, and new, replacement head units have been long discontinued. there is nothing in the FSM about unit repair of the head assembly, only to replace the unit if problems exist. your only option is to find a used unit and replace your assembly, or buy one for parts. I recently replaced my "AC/heater/vent select switch" on my 85 with one from another assembly, that I purchased from fleabay years ago.



if you need to replace one or the other, both manifolds are only held in place with one small screw. should be an easy fix. good luck....

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Old May 6, 2018 | 09:39 AM
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Default o.k. Thanks Joe c

Originally Posted by Joe C
have you actually identified the cause of the vacuum leak? there is a two-way check valve, a small round accumulator, and a bunch of vacuum hose that adds to the system. if it is indeed the AC head unit, there are actually two "select manifolds" on the head unit. is it the manifolds, or the vacuum couplers or hoses that attach to the manifolds? as far as I know, repair parts are not available, and new, replacement head units have been long discontinued. there is nothing in the FSM about unit repair of the head assembly, only to replace the unit if problems exist. your only option is to find a used unit and replace your assembly, or buy one for parts. I recently replaced my "AC/heater/vent select switch" on my 85 with one from another assembly, that I purchased from fleabay years ago.



if you need to replace one or the other, both manifolds are only held in place with one small screw. should be an easy fix. good luck....


There are a couple of them on ebay I might pick one up and hope for the best.
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