cruise control vacuum lines
Thread Starter
Racer
Joined: Aug 2014
Posts: 287
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From: Toledo
cruise control vacuum lines
where do the two vacuum lines come from and go to? I can see the one dives under the power brake booster then disappears from there. both my lines need changed. thanks in advance.
chad
95 Lt1
chad
95 Lt1
Last edited by chadk; Jun 14, 2015 at 12:57 AM. Reason: include year
Race Director
Joined: Aug 2000
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not 100% sure on an LT1 car, but on my 85, there are two lines - one 5/32" hose that connects to a "tee" just under the master cylinder. one side of the "tee" goes to the fuel vapor emission system at the far-forward LH side of the car. not sure where the other side goes, but I'm thinking somewhere to the intake manifold. the other line is a 7/32" line that goes through the firewall just under the brake booster. on the interior side of the firewall, I have no idea where the 7/32" hose goes, but i'll soon be finding out. I'm replacing most of the vacuum lines on my 85, and that 7/32 hose is fairly deteriorated at the cruise control module, although I may do a splice repair since most of the hose looks to be in fairly good condition. just not cherishing the thought of getting under the dash of my 85 just to replace a piece of vacuum hose. 
Last edited by Joe C; Jun 14, 2015 at 05:44 AM.
Race Director
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I just did my 94 and did it the hard way pulled the bottom of the dash and the seat also the battery.
Now the easy way. The line that goes threw the firewall goes to a switch on the brake pedal.
Don't take anything off or out. Just reach up under the dash and grab the hose most likely still in good shape there if so cut it in a easy spot. Then cut it in half long ways about six inches. Then run some bailing wire in the hose a fair bit. Then use electric tape to hold it make it tight. Then lube up the hose and pull it out from under the hood. Put your new line back in revese. Then cut flush and put a connector to the hose to the switch. Or pull the car apart and lay on your back and cuss trying to get the hose off and on the switch.
Now the easy way. The line that goes threw the firewall goes to a switch on the brake pedal.
Don't take anything off or out. Just reach up under the dash and grab the hose most likely still in good shape there if so cut it in a easy spot. Then cut it in half long ways about six inches. Then run some bailing wire in the hose a fair bit. Then use electric tape to hold it make it tight. Then lube up the hose and pull it out from under the hood. Put your new line back in revese. Then cut flush and put a connector to the hose to the switch. Or pull the car apart and lay on your back and cuss trying to get the hose off and on the switch.
Race Director
Joined: Mar 2015
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I just did my 94 and did it the hard way pulled the bottom of the dash and the seat also the battery.
Now the easy way. The line that goes threw the firewall goes to a switch on the brake pedal.
Don't take anything off or out. Just reach up under the dash and grab the hose most likely still in good shape there if so cut it in a easy spot. Then cut it in half long ways about six inches. Then run some bailing wire in the hose a fair bit. Then use electric tape to hold it make it tight. Then lube up the hose and pull it out from under the hood. Put your new line back in revese. Then cut flush and put a connector to the hose to the switch. Or pull the car apart and lay on your back and cuss trying to get the hose off and on the switch.
Now the easy way. The line that goes threw the firewall goes to a switch on the brake pedal.
Don't take anything off or out. Just reach up under the dash and grab the hose most likely still in good shape there if so cut it in a easy spot. Then cut it in half long ways about six inches. Then run some bailing wire in the hose a fair bit. Then use electric tape to hold it make it tight. Then lube up the hose and pull it out from under the hood. Put your new line back in revese. Then cut flush and put a connector to the hose to the switch. Or pull the car apart and lay on your back and cuss trying to get the hose off and on the switch.
8th Gear
Joined: Oct 2015
Posts: 8
Likes: 1
I just did my 94 and did it the hard way pulled the bottom of the dash and the seat also the battery.
Now the easy way. The line that goes threw the firewall goes to a switch on the brake pedal.
Don't take anything off or out. Just reach up under the dash and grab the hose most likely still in good shape there if so cut it in a easy spot. Then cut it in half long ways about six inches. Then run some bailing wire in the hose a fair bit. Then use electric tape to hold it make it tight. Then lube up the hose and pull it out from under the hood. Put your new line back in revese. Then cut flush and put a connector to the hose to the switch. Or pull the car apart and lay on your back and cuss trying to get the hose off and on the switch.
Now the easy way. The line that goes threw the firewall goes to a switch on the brake pedal.
Don't take anything off or out. Just reach up under the dash and grab the hose most likely still in good shape there if so cut it in a easy spot. Then cut it in half long ways about six inches. Then run some bailing wire in the hose a fair bit. Then use electric tape to hold it make it tight. Then lube up the hose and pull it out from under the hood. Put your new line back in revese. Then cut flush and put a connector to the hose to the switch. Or pull the car apart and lay on your back and cuss trying to get the hose off and on the switch.
Race Director
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Hi antfarner. I'm trying to repair/replace the line that goes through the firewall on my 96. Got under the dash and located the 7/32 hose that goes through the firewall. There is a large 2" grommet plug that is very tight and I can't dislodge it, and the hose will not push through or pull through. I thought of cutting the hose and using a 3/8 socket set to link it to the new line and push/pull it through the Firewall and connecting tho the controller, but could not get the existing line (which is good under the dash) through the grommet. Any ideas hos to get the grommet loose or to get he hose to slide through? Not much room to work under there, can omly get one hand in there laying on my back....too many wiring bundles, other junk in the way.
Last edited by antfarmer2; Oct 24, 2016 at 05:14 AM.
Team Owner
Joined: Sep 2003
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JimmyC - a fellow here locally generally uses a "hard-tube" to feed through the existing hose that's in the grommet. Requires little or no lube to accomplish and you do hose on either side to complete the connection. I've never needed to replace a pass-through for vacuum but I believe it's what I'd do.
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8th Gear
Joined: Oct 2015
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Thanks, I'll give it another go...tomorrow. After spending almost two hours taking the seat and lower dash out and laying on my back struggling with the stuck line, this 71 year old needs a little recovery time.
Race Director
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Do not mess with the grommet just the hose.
1st Gear
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I just did my 94 and did it the hard way pulled the bottom of the dash and the seat also the battery.
Now the easy way. The line that goes threw the firewall goes to a switch on the brake pedal.
Don't take anything off or out. Just reach up under the dash and grab the hose most likely still in good shape there if so cut it in a easy spot. Then cut it in half long ways about six inches. Then run some bailing wire in the hose a fair bit. Then use electric tape to hold it make it tight. Then lube up the hose and pull it out from under the hood. Put your new line back in revese. Then cut flush and put a connector to the hose to the switch. Or pull the car apart and lay on your back and cuss trying to get the hose off and on the switch.
Now the easy way. The line that goes threw the firewall goes to a switch on the brake pedal.
Don't take anything off or out. Just reach up under the dash and grab the hose most likely still in good shape there if so cut it in a easy spot. Then cut it in half long ways about six inches. Then run some bailing wire in the hose a fair bit. Then use electric tape to hold it make it tight. Then lube up the hose and pull it out from under the hood. Put your new line back in revese. Then cut flush and put a connector to the hose to the switch. Or pull the car apart and lay on your back and cuss trying to get the hose off and on the switch.
Pro
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Not sure he will get your message. He hasn't been active on this forum in over 5 years. I learned when I first joined this awesome forum to check the dates of the post.
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