Fixing vacuum line through the fire wall?

adamclyde

adamclyde

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San Clemente, CA
Hi folks!
so my air control was stuck on defrost vents and found the problem to be a broken vacuum line right at the junction as the line passes through the firewall. As you can see from the picture, it’s broken off inside the female junction. I’ve tried prying it out with needle nose pliers and tweezers to no avail, which means I can’t just re-insert it. So I thought I would splice the vacuum line, but there is no give in the line as it passes through the fire wall to the engine so I can‘t access the line to splice or fix it.

so two question, first, if I want to access the line from inside the jeep, do I need to dismantle the dash? I took off the glove compartment and couldn’t find the entry point of the hose for the life of me.

second, how would you fix this one? That female part doesn’t give so I can’t pull it out to access any more of the hose. Is there an easy fix without replacing the whole line? I thought of shrink wrap but that junction diameter is pretty different between the male-female hose so I’m not sure it would give a good air seal? Any thoughts appreciated!

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Usually there is slack...you an cut it and splice with a piece of tubing slightly larger than the od of the existing vacuum hose
 
Don’t dismantle the dash-

Several options-get a multi fitting vacuum line accessory kit at a chain parts store - they sell a reducer or you can combine 2 or so

Also google the replacement line set- if that is a hard line that plugs in, thread a drywall screw in by hand and pull it out

Worse case put a larger line over all of it then slide a smaller line in it -

Those lines get brittle with heat - may be good to by the replacement part soon

Easy fix, very little pull on that- be gentle with the rest of it.

Let us know how it it goes.
 
Try using needle nose players to pull the black hose out a bit. If you can get it out you can slip a piece of 3/32” vacuum hose (windshield washer hose) and slide it on to splice the hose. A drop of super glue will make it stay.
 
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Had a similar problem, managed to solve it (so far) with a chunk of rubber hose with a particularly thick wall. One end was left unmodified and slips nicely onto the broken rigid vacuum line in the engine compartment. The other I opened up a bit with a drill so that I could fit it over the outside of the stub going through the firewall.

I don't think it's a perfect fix because it takes 30 seconds to a minute or so after starting the Jeep for the vacuum to pull hard enough to move the vents from the windshield to the dash, but it's enough for now.
 
IOwnCalculus said:
View attachment 367213

Had a similar problem, managed to solve it (so far) with a chunk of rubber hose with a particularly thick wall. One end was left unmodified and slips nicely onto the broken rigid vacuum line in the engine compartment. The other I opened up a bit with a drill so that I could fit it over the outside of the stub going through the firewall.

I don't think it's a perfect fix because it takes 30 seconds to a minute or so after starting the Jeep for the vacuum to pull hard enough to move the vents from the windshield to the dash, but it's enough for now.
Click to expand...

The delay may be caused be the reservoir being empty, there may be a small leak
 
You can remove the broken brittle section of poly Black vacuum source line, feed a new section of 1/8" poly line in, cut off the brittle section until good line is found, join the two sections and slide a small section of rubber hose on the end to connect to the factory vacuum Tee.
This is the most difficult resolution, but you will never have to address this problem again.

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So many great thoughts. thanks folks.

AndyG said:
Also google the replacement line set- if that is a hard line that plugs in, thread a drywall screw in by hand and pull it out
Click to expand...

Great suggestion on the drywall screw. Going to try that this afternoon. If that works, then I'll try and repair like @CharlesHS suggested. If not, I'll do the larger hose fitment like @IOwnCalculus and @NskLJ suggestion. Thanks all! Stay tuned.
Click to expand...
 
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CharlesHS said:
You can remove the broken brittle section of poly Black vacuum source line, feed a new section of 1/8" poly line in, cut off the brittle section until good line is found, join the two sections and slide a small section of rubber hose on the end to connect to the factory vacuum Tee.
This is the most difficult resolution, but you will never have to address this problem again.

View attachment 367277
Click to expand...

Hey Charles, can he go in behind the glove box , splice that and put line with that i.d. over the 2 parts and extend it out under the hood?

Just wondering if that would help him til he finds the line-

And OP, dash removal should not be needed under any scenario if I’m thinking right, which doesn’t happen much.
 
CharlesHS said:
You can remove the broken brittle section of poly Black vacuum source line, feed a new section of 1/8" poly line in, cut off the brittle section until good line is found, join the two sections and slide a small section of rubber hose on the end to connect to the factory vacuum Tee.
This is the most difficult resolution, but you will never have to address this problem again.

View attachment 367277
Click to expand...

I've got a similar hvac vacuum leak that I'm having trouble tracking down, seeing yours laid out like that makes me think I should just attempt to remove it all and inspect it on the bench. Or am I insane?

Really I don't know how to troubleshoot a vacuum leak. Ive read about pressure testers but I don't even know what to hook up to what, and what lines should show what pressure anyway.
 
AndyG said:
Hey Charles, can he go in behind the glove box , splice that and put line with that i.d. over the 2 parts and extend it out under the hood?

Just wondering if that would help him til he finds the line-

And OP, dash removal should not be needed under any scenario if I’m thinking right, which doesn’t happen much.
Click to expand...

Andy,

YES.. you can go in thru the glove box (remove it), but your hands will need to be small since there the vacuum line snakes in where it is difficult to see.
 
hear said:
I've got a similar hvac vacuum leak that I'm having trouble tracking down, seeing yours laid out like that makes me think I should just attempt to remove it all and inspect it on the bench. Or am I insane?

Really I don't know how to troubleshoot a vacuum leak. Ive read about pressure testers but I don't even know what to hook up to what, and what lines should show what pressure anyway.
Click to expand...

I used a MityVac that I used for bleeding brakes and connected the tubing in the kit to each individual colored line at the white connector and applied vacuum watching the gauge to see if it drops. You will need to ensure the connections fit snugly during the test. I applied vaseline to the connections to decrease the chances of leakage.

https://www.amazon.com/dp/B00265M9SS/?tag=wranglerorg-20

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Since everybody seems to act like this is the simplest task on earth, maybe somebody smarter than me can show me how. I’ve got a vacuum tester pump thing from Autozone, and access to the vacuum lines behind the glovebox. But none of these fittings in the tester will mate to these connections.

Or am I supposed to remove the colored hoses from the fittings?

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Mine came with different fittings and a smaller diameter hose.
I slipped the smaller diameter hose over the male connectors and the smaller pointed black fittings into the female connections.
The clear female fitting is removable from the vacuum tubing connectors to expose the male connectors.
 
For the issue of not being able to pull out the broken piece, why not find a tiny screw and thread it in to give you something to grab on to?
 
hear said:
Since everybody seems to act like this is the simplest task on earth, maybe somebody smarter than me can show me how. I’ve got a vacuum tester pump thing from Autozone, and access to the vacuum lines behind the glovebox. But none of these fittings in the tester will mate to these connections.

Or am I supposed to remove the colored hoses from the fittings?

View attachment 368079

View attachment 368080

View attachment 368082
Click to expand...

Nobody said it was the simplest job on earth but it's not overly difficult. First thing to do is throw that vacuum thingy in the trash.

Ok now grab a stethoscope and start the jeep. You will start listening and feeling around the vacuum lines. It will be fairly obvious where the leak is.
 
P man said:
Nobody said it was the simplest job on earth but it's not overly difficult. First thing to do is throw that vacuum thingy in the trash.

Ok now grab a stethoscope and start the jeep. You will start listening and feeling around the vacuum lines. It will be fairly obvious where the leak is.
Click to expand...

It’s a whole lot easier to do a visual inspection, and just bend the lines they will break at the crack. I have only had issues with the lines in the engine compartment never inside the vehicle.
 
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