Vacuum/boost hose location

92stockbird

Registered User
Hey y'all,

The vacuum/boost gauge quit on my 92 sc, and I'm thinking it's either the hose has come loose, or cracked. I've found the hose at the cluster, but I do not know where it connects at the back of the engine, nor can I see it come out of the firewall to be able to trace it.

Thank you,
Jim

John 3:16
 
Hey y'all,

The vacuum/boost gauge quit on my 92 sc, and I'm thinking it's either the hose has come loose, or cracked. I've found the hose at the cluster, but I do not know where it connects at the back of the engine, nor can I see it come out of the firewall to be able to trace it.

Thank you,
Jim

John 3:16

Hi Jim,

It connects to the return plenum where it turns down to enter the lower intake manifold. The connection point is right near the ACT sensor. The hose comes out of a bundle of stuff running along the firewall.
 
Does the cluster need to be removed in order to change this hose? Or can I just reach up laying on my back? I need to do this myself today, mine finally cracked beyond repair after 19 years
 
Does the cluster need to be removed in order to change this hose? Or can I just reach up laying on my back? I need to do this myself today, mine finally cracked beyond repair after 19 years

Yes tom i think u need to remove cluster in order to plug a new vacuum hose into the gauge
Find a spot to route out of the firewall into the engine bay and connect new one to return plenum

Laying on ur back may be quite uncomfortable and very hsrd to get the hose on there but I never tried that way
Mine is actually apart on dash since im adding gauges and my wideband so I can take pics so u see where the vacuum hose goes through or if there is space from beneath , ill post em up on fb so u can see
 
Jim I hope this helps u couldn't find a better pic from there u can follow the small hose
 
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Yes tom i think u need to remove cluster in order to plug a new vacuum hose into the gauge
Find a spot to route out of the firewall into the engine bay and connect new one to return plenum

Laying on ur back may be quite uncomfortable and very hsrd to get the hose on there but I never tried that way
Mine is actually apart on dash since im adding gauges and my wideband so I can take pics so u see where the vacuum hose goes through or if there is space from beneath , ill post em up on fb so u can see

Awesome thanks Miguel, I had a feeling i would have to remove the cluster, as nothing with these cars is ever easy lol. Although it shouldn't be terrible to do. I just gotta make sure I can pull it through the firewall in the same spot as the original
 
Awesome thanks Miguel, I had a feeling i would have to remove the cluster, as nothing with these cars is ever easy lol. Although it shouldn't be terrible to do. I just gotta make sure I can pull it through the firewall in the same spot as the original

You are right on that one some so simple is always a pain on these cars lol
Yes once u remove the cluster its easier to follow the hose/line, I tried following it from the engine bay side but the crimped wire bundle made it hard to follow
I ran a new line from my gauge that was thinner and made it easier passing through the firewall


Had this pic on my phone but ill take better ones later on today
 
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You are right on that one some so simple is always a pain on these cars lol
Yes once u remove the cluster its easier to follow the hose/line, I tried following it from the engine bay side but the crimped wire bundle made it hard to follow
I ran a new line from my gauge that was thinner and made it easier passing through the firewall

I have a thicker, yet more pliable hose, so hopefully i can just push it through and get it to a spot in the engine compartment where it can be grabbed and ran to the return plenum, however only time will tell lol
 
I have a thicker, yet more pliable hose, so hopefully i can just push it through and get it to a spot in the engine compartment where it can be grabbed and ran to the return plenum, however only time will tell lol

Should be able to get it
If u ran a 12v cable for ur audio u can use the same path to get to the engine bay and then route to return plenum if u find that the original spot is too hard to get through

BUT it will make alot more sense once ur in there
 
Okay Jim, I just did this this morning, and i have a few bits of advice:

1) You'll need to remove the drivers side inner wheel-well cover in order to get to the line

2) There are 2-3 "junctions" underneath the dash that the wire goes to (meaning it isn't one straight piece of vacuum hosing).

3) It will be very difficult to reuse the factory routing for the line, so I personally would recommend coming through the firewall at an easier location. I personally did this through the hole i made for my LC-1 wiring

It is about a 2 hour job, mostly because you have to be careful when handling the dash pieces so you dont end up cracking them

Hope this helps,
Tom
 
vacuum/boost hose location

I had thought the hose ran from that nipple to the gauge. I' am going to do this tomorrow, as we are getting showers, and I don't have a garage to work in. Thank you for the pics, and help.

Jim

John 3:16
 
It does run from the gauge to the nipple,
However there are a couple of like connectors that go along the length of the hose
 
vacuum/boost hose location

From inside the car, we found where the hose routes through the dash, but we are unable to find where it enters the engine bay. Also can't find a hole to run the hose into the car. Where is a good place to drill a hole?
 
From inside the car, we found where the hose routes through the dash, but we are unable to find where it enters the engine bay. Also can't find a hole to run the hose into the car. Where is a good place to drill a hole?

As LIVipers alluded to earlier, the hole is there. Take off the fender liner and you should see the hose coming out of the passenger compartment, into the space above the wheel, then into the engine bay.

The only question is, can you reach the broken part of the line? If it is broken behind the dash, it may be hard to fish a new line through the same routing. If it is broken in the engine bay or inside the wheel well, then there's nothing to it. Just splice with a section of rubber hose.
 
vacuum/boost hose location

The line broke about 2 feet from the nipple inside the engine bay. The hard part is, finding where it broke.


Jim

John 3:16
 
If you have about 2 feet of hose left, then it probably broke right where the line comes through from the inner fender. I would try pulling the wheel well liner and see if you can find the line in there. If so, just put a splice at that point.
 
vacuum/boost hose location

My youngest brother came to return my Mustang GT, and while he was here, we took flashlights and found here it had broken. In the "hole" next to the clutch fluid reservoir, and in front of the round green n white part. Now I need to get smaller dia. hose to fix it.

Thank you for ALL your help

Jim

John3:16
 
vacuum/boost hose location

My brother found where it had broken, and I as able to patch it.

My next question is: Where in the 5spd trans is the speedo gear, and ho do I access it? Also, what tool is used to remove th ring on the top of the down tube, to replace the pc valve?

Thank you,
Jim

John 3:16
 
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