Fresh air intake water drain replacement techniques

[bugstrider]

When I removed our fresh air box for repairs, the brittle plastic tube attached to the bottom of the air box exploded like a grenade. I have acquired a couple of different replacement possibilities that I can try. However, our 78 911SC has/had(compressor failed) AC and I noticed that the water drain tube drops down and through the smugglers box to the outlet through the floor and that the drain tube is snugly tucked in behind the A/C evaporator housing, if I have my terminology correct.

Which leads me to our delima. Do any of you have any suggestions on how to replace this entire length of drain tube with the AC component in place in the smugglers box and can I expect the remaining tube to fracture upon contact?

I guess I should ask if this drain tube is a single piece that runs the entire length from the air box to the floor outlet or is it two pieces? The Bentley book doesn't really cover this and my search on PP hasn't turned much up regarding a successful method even though I was changing up my search criteria.

Thanks for your impute on this matter.

Cheers Trevor

I can post pictures if need be. I will just need to wait until Tuesday or Wednesday depending on work schedule.

[pete3799]

It is a one piece hose. I had to remove the ac to access it. There's a metal tab on the rear wall of the smugglers box that the hose passes through (or gets bent around the hose). Doubt you can fish it through without removing the evaporator.

[jlynch1960]

There was a guy on the used parts section selling the replacement tubing a week or so ago. $10 plus shipping if I recall.

[SCadaddle]

No A/C in the smugglers box of my 69 912 but I did use a suitable size piece of heat shrink tubing for the drain. Very flexible.

[bugstrider]

Originally Posted by pete3799

It is a one piece hose. I had to remove the ac to access it. There's a metal tab on the rear wall of the smugglers box that the hose passes through (or gets bent around the hose). Doubt you can fish it through without removing the evaporator.

Thanks, I was figuringing my hand would be forced on this. Since you have done this, do you have any pointers or suggestions? Any of those " wished I would have know that before I started" moments? 🤔

Cheers

[DRACO A5OG]

If your car is like the 3.2 AC system, after taking the large outlet hose and motor off the evaporator box. Go to the passenger side foot well and remove the relay housing under the foot board, it holds the evap box in place. You can now lift the box out, keep the evap connected and move it out of the way. You can now look down the bottom of the smuggler's box. Be prepared, it can get ugly.

[bugstrider]

Originally Posted by jlynch1960

There was a guy on the used parts section selling the replacement tubing a week or so ago. $10 plus shipping if I recall.

Yup, my section of pipe arrived yesterday. One of my options. In looking at the flex pipe provided, it's the black corrugated fish pond hose. My only concern will be the OD and if it will fit into the drain hole. Another option I have read about is using a washing machine drain hose. It's OD is a little smaller and it too is quite flexible.

I'll start into the repair just as soon as I figure the best way to remove the evaporator/blower asymbly. Oh joy

[DRACO A5OG]

Oh yeah that large hose is brittle too, so be prepared to be gentle. No biggy, if you do kill it, just get some 3" laundry dryer hose at the hard ware store. Works just fine.

[bugstrider]

Originally Posted by DRACO A5OG

If your car is like the 3.2 AC system, after taking the large outlet hose and motor off the evaporator box. Go to the passenger side foot well and remove the relay housing under the foot board, it holds the evap box in place. You can now lift the box out, keep the evap connected and move it out of the way. You can now look down the bottom of the smuggler's box. Be prepared, it can get ugly.

As usual, thanks Draco for your insight and pointers, very valuable to this forum and its members.

I'll be sure to do that. I haven't looked yet, but do you know if the small 6-8" piece of flex ducting that is attached to the evaporator is available? Mine looks very crusty and I'm concerned that it too will tear apart the moment it gets moved around.

[bugstrider]

Originally Posted by DRACO A5OG

Oh yeah that large hose is brittle too, so be prepared to be gentle. No biggy, if you do kill it, just get some 3" laundry dryer hoes at the hard ware store. Works just fine.

Wow! That is freaky, you read my mind. Obvious by the fact I posted that exact question three minutes after you posted this comment.

Proves my point just how helpful you are to everyone....��

Thanks again,
Trev

[DRACO A5OG]

:-D, oh shucks just doing my part Brother Trev!

I wish we all had ESP, it would make communication so much more efficient :-)

[bugstrider]

Ok then,

Having a day off today I decided to get started on replacing the fresh air drain hose in our 78 911SC with a defunct AC system. Essentially I will be posting a description and pics of my progress with the intent of assisting someone like myself that knows enough about these great cars to be really, really............really dangerous.

The area I will be working on.


The AC blower and Evap box I will be removing.


And the little bee-o-tch of a brittle drain hose that is the cause of my misery.






Some of the items that need to be pulled apart and removed from the trunk area.







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[bugstrider]

First thing first, get the car out from its car cover silver tarp cocoon.


Then I busted out one of the best Harbor Freight goodies I've purchased in a long time. In fact everyone should have one stashed in the trunk of the 911.

The magnetic fender guard.




Really is a piece of mind now knowing I will lessen the change of damaging the pain due to a wayward button or buckle since I will darn near be balancing on the fender. Boy does it suck having short legs and T-Rex arms.





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[bugstrider]

Getting started I began removing the four 10mm bolts that hold on the barrier that covers all the inerts of the ventilation system.(not shown)

I did take some yellow marker pen paint and marked the metal lines that control the flapper valves of the system. I also marked the flex hose as it came off so that I would be sure which one went where. Marking isn't a necessity but your like me, I have gone deep on several different items on this car and now on the verge of mixing things up. Totally my bad but hard not too.
This all started with a ball joint that lead into a suspension make-over going from ER rubber to poly bronze, brake Referb, cooling fan overhaul by Mark Motshagen. Seat covers and a steering wheel hand stitched re-cover, you all get the idea.... The list goes on.

Squirrel moment past, marker paint.






Removed the aluminum grill and screen.







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[bugstrider]

I then began pulling the valve cable retention clips apart.







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[DRACO A5OG]

Damn those are shinny fitments, like new I say

[bugstrider]

Hahahaha, thanks.

Sorry to read about your rocker issue. That really sucks. On the bright side, you caught it before major damage occurred.

Your ride looks fantastic, even on the flatbed.

Gotta ask, what size tires are you running as well as your height settings? Me likes!


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[bugstrider]

It continues;

Once the cable retention clips are off, the cables can be removed.




On the top wire, it slides through a small drilled bolt and the cable/wire is trapped in place by a series of washers. Just keep this in mind so you don't drop them loosing them in the pit of the unknown. Unless you like hunting things with an extension magnet. If so, rock on and fish strong.





Now I began removing addition items to commence with the fresh air box.










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[bugstrider]

Once all the boxes, brackets, cables and hoses have been removed, the Air box can be pulled out after its two retention screws are pulled.




On the lower section of the fresh air box, you will find the electrical connector to the fan. This needs to be removed as well, light pressure to remove it only..... No prying with small screwdrivers.




After this is completed, the air box will rotate out of its location and out of the car.







Now I show everyone my level of ignorance regarding this drain hose!

When I removed all of this schtuff last year so I could replace my environmental control head w/cables, this is when the brittle drain hose fragmented into teenie weenie little shards. Not understanding that it was a small piece of a larger hose that descended into the smugglers box through the bottom of the car.

This clearly supports my earlier state me of knowing enough to be dangerous........

Thinking it was just a straight outlet and that the tube was just there to direct water and debris into its opening, I thought I could be clever and rig my own fix.







Which would have done me absolutely no good by just dumping water into the smugglers box. The lessons we learn on this journey.


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[bugstrider]

Once the air box is removed, I now get to tackle the evaporator unit.

I begin with removing the brackets and associated wire connections.











Once that was done, I went to work on the AC hose connectors.


Not really sure what this gooy crap is that covers the evaporator fittings. Want to eventually referb the AC in the car at some point so I wonder if I should replace the evaporator with a more efficient one while its out of the car.



The larger hose was really tight and I had to use a penetrating oil.

Great stuff, although kinda tough milking those little critters.



Another good tool set to have are thin wrenches. Got this set at a small tool shop here locally. Used them on several things, one being the ball joint upgrade and have been pretty useful on this project.