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vacuum question

  • Thread starter Thread starter streetdemon70
  • Start date Start date Sep 8, 2005
S

streetdemon70

New Member
Apr 4, 2005
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Sep 8, 2005
#1
  • Sep 8, 2005
  • #1
On my 70 coupe the vacuum canister that is mounted in the fender well has a port for two hoses. I have the bottom port hooked up to something but i dont have anything hooked up to the top port? does anyone know what hooks up to the top port?
--A
TIA
 
C

cgstang

New Member
Mar 5, 2004
16
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0
Sep 9, 2005
#2
  • Sep 9, 2005
  • #2
one is vacuum in and the other is vacuum out
 

mudbilly

Member
Jun 3, 2005
175
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South County, Maryland
Sep 9, 2005
#3
  • Sep 9, 2005
  • #3
what it's purpose is?????

i have been looking at that thing for 5 years and always wondered why it was there......
 
C

Clark

Founding Member
Aug 5, 1999
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Rowlett,Texas
Sep 9, 2005
#4
  • Sep 9, 2005
  • #4
My 69 should be very similar to the 70 application, but the vacuum can is there like a storage tank so when you need vacuum to move the heater/AC controls it will provide a large amount of suction to move the actuators quickly. This is different from earlier models that had some cables.
 

65ShelbyClone

Founding Member
Sep 9, 2000
4,675
38
119
Antelope Valley, SoCal
Sep 10, 2005
#5
  • Sep 10, 2005
  • #5
Clark said:
My 69 should be very similar to the 70 application, but the vacuum can is there like a storage tank so when you need vacuum to move the heater/AC controls it will provide a large amount of suction to move the actuators quickly. This is different from earlier models that had some cables.
Click to expand...

Dang, so THATS what its for! I have a vac canister too, but had no idea what it was needed for. Thing is, mine only has one port .
 
J

jbuening

Member
Apr 28, 2005
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Sep 12, 2005
#6
  • Sep 12, 2005
  • #6
The vacuum cans are for A/C cars only. You should have a grommet with two small vacuum hoses coming through the firewall right above the passenger valve cover towards the top of the firewall. One goes to the heater hose valve that stops the coolant from going into the heater core and the other vacuum hose goes to the small port in the vacuum can. Then there should be a hose going from the large port on the vacuum can to the plastic vacuum tree on the firewall. You might want to test the vacuum can for leaks, cause mine had a hole rusted through it and would cause a vacuum leak and is the last thing that most people think of when diagnosing a vacuum leak. If you need pics please let me know. There is a J clip on the firewall that holds the two vacuum hoses when it runs along the firewall to the vacuum can.
 

mudbilly

Member
Jun 3, 2005
175
0
16
South County, Maryland
Sep 12, 2005
#7
  • Sep 12, 2005
  • #7
jbuening said:
The vacuum cans are for A/C cars only. You should have a grommet with two small vacuum hoses coming through the firewall right above the passenger valve cover towards the top of the firewall. One goes to the heater hose valve that stops the coolant from going into the heater core and the other vacuum hose goes to the small port in the vacuum can. Then there should be a hose going from the large port on the vacuum can to the plastic vacuum tree on the firewall. You might want to test the vacuum can for leaks, cause mine had a hole rusted through it and would cause a vacuum leak and is the last thing that most people think of when diagnosing a vacuum leak. If you need pics please let me know. There is a J clip on the firewall that holds the two vacuum hoses when it runs along the firewall to the vacuum can.
Click to expand...

thankyou very much........
 
J

jbuening

Member
Apr 28, 2005
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Sep 12, 2005
#8
  • Sep 12, 2005
  • #8
One thing i did forget is that the vacuum can is also used for the tilt release for cars that came with tilt steering columns. Not sure what years it was used but i've heard of 67 and 68's having the cans for the tilt columns. Oh and you are welcome
 
S

streetdemon70

New Member
Apr 4, 2005
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Sep 12, 2005
#9
  • Sep 12, 2005
  • #9
thanks turns out mine had a hole in it. got it fixed and the car runs much better. thinking since i got rid of my ac i can get rid of that vacuum can right? all i really need vacuum for is the brakes correct?
--A
 
J

jbuening

Member
Apr 28, 2005
399
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Sep 12, 2005
#10
  • Sep 12, 2005
  • #10
I wouldn't see why not. You would have a hole in the inner rear fender panel though. Do you have a stock cam or a beefier one? The more radical the cam the more vacuum the cam needs, thus the reason for aftermarket vacuum canisters that are sold by summitracing and jegs. As long as the hole was patched i wouldn't think it would hurt anything, if anything increase your vacuum a bit. If your A/C is gone and you don't have a tilt column (not sure if the tilt columns in 70 used the can) then its up to you to remove it.
 
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