Repair vacuum line

[SirFoxx]

Hello-- on my '86 TC, the po bypassed my heater core by looping the coolant hose from the thermal blower shutoff back to the return line, I think. (haven't looked too close at it). I currently have the two vacuum lines originally going to the TBL plugged so that my A/C isn't going through the defrost vents. In my adventure of looking for vacuum leaks, I found them both to be broke / melted, hence why I plugged them.

Is there a way to repair those tiny vacuum lines? What is the purpose of that TBL? Is it 100% needed? What is the best solution to restore heat to my car?

[His Royal Ghostliness]

The TBL's purpose is to prevent idiots from freezing their feet in wintertime by running the heat on floor setting while the engine is still cold. Funny how passenger cars got that, but trucks did not, and a 14k GVW F-Superduty can do a whole lot more damage than a Panther can should driver's feet get cold enough to where he/she cannot move them properly to safely operate the vehicle. In any case, keeping those vacuum line capped off is the proper thing to do - it eliminates a stupid "safety" feature that is more trouble than its worth. However, this is only half of the job - the other half is taking those two fat wires that plug into the TBL, and cutting their connector off and connecting the two wires together - I prefer weatherproof butt connects for this, but in a pinch even a household wire nut will do. Once you got that done, replace the TBL with a simple straight-thru 5/8" barb union (parts store have it in plastic, hardware store may have it in brass), then use your factory-style hoses for the heater core.

Do keep in mind there's probably a reason why the previous owner bypassed the heater core, maybe it leaks? You'll find out when you plumb it back in, but just so you know replacing it is really not a fun job, at all!

[DerekTheGreat]

...Do keep in mind there's probably a reason why the previous owner bypassed the heater core, maybe it leaks? You'll find out when you plumb it back in, but just so you know replacing it is really not a fun job, at all!

LoL, yeah that should be fun to discover. I remember when I dropped the new engine in the Fury and hooked the heater core back up as a teen.. "Hmm, it smells like breakfast in here... What's this orangish green goo--Oh.. Great.."

Rather than cut the connector for the TBL and put the barb union in I was thinking of doing the following for my car: Reman the heater doohickey thing with it's little plunger that moves as the engine heats up, dust a tad of silicone grease on the rubber thing for the vacuum lines and then join the contacts together by some means so it works again. Only to retain the factory appearance. I've already tried to reman a few of these and it works for about a week. The floor vent continues to open but for whatever reason I lose the blower. I've checked the operation of it all and it moves the stupid slider thing to make contact between the two tabs yet I get no current flow, blows my damn mind. Maybe the tabs are too worn? They do have grooves in them...

[His Royal Ghostliness]

I think reliability and safety should take priority over factory appearance. Two important things to remember here:

1) you're working with plastic that's been baked at almost 200 degrees for almost 30 years now, even if it wasn't happening every day. Fatigue has built up into the part, there have been reports of them things just blowing apart at higher engine speeds, especially if the core has a restrictor at its inlet to prevent ballooning.

2) all the current for the blower flows thru the TBL, on high speed that's a lot of juice. Marginal contacts make for high resistance, which makes heat, which melts things down.

If you wanna keep messing with an unnecessary overcomplicated setup with (mostly age-related) reliability issues that's your call, but I'd much rather do away with it all and know there are no more weak links in the system. I'm thinking no one will really notice the thing is gone anyways unless they know Panthers very well, and if they do then they'll also know why it's removed.

[Tiggie]

How much of the lines are left? If you have the ends you can patch them with small rubber hose. Mine have been like that for almost a decade.

[gadget73]

The TBL itself usually leaks even if the lines don't. I seal them off and go on with my working climate controls. The electrical bit on the TBL is bypassed and the TBL itself hasn't been on the car in a very long time. If my tootsies get cold, I just shut off the heat until the car warms up enough to make heat.

[SirFoxx]

So I got my heater core reconnected and found out why it got disconnected... Boy did it reek in my car! Guess I get to replace my heater core this weekend.

[His Royal Ghostliness]

Figure 6-7 hours taking your time, drop the column with the steering wheel resting on the seat to make dash removal easier, and you don't need to actually remove it all the way, just unbolt it and swing it back away from the firewall far enough to get to the plenum with the core. Annoying job for sure, but all in all not too horrible.

[VicCrownVic]

Check out the heater core writeup thread, the first section should be most similar to your TC. There may be some minor differences between CV/MGM and TC, but there is a lot of detail in that thread that should be useful for you if you need it.

[gadget73]

Get yourself a right angle ratchet screwdriver. The line of small screws up against the windshield have clearance problems and most other things don't fit in there very well. I have done it with a #2 phillips bit and a 1/4" wrench but that sucks. Harbor Freight sells one. The $3 it will cost you will be very much worth it.

[sly]

like this

http://www.harborfreight.com/8-piece-right-angle-screwdriver-92630.html

I used one of these when I did the core in my 88...

[SirFoxx]

So I got my core changed this weekend, and I didnt have to pull my dash off. There is a video on youtube of someone changing the core on a crown vic, and basically what he did was he took out the passenger and middle dash bolt, undid the glove box, and pulled his dash outwards a bit, and rotated the entire box downwards. I did this method, and while I was able to get mine changed, I dont think I would recommend it to anyone. It left gouges in my heater box, and I pinched a vacuum line.

[gadget73]

Thats actually the factory method believe it or not. Personally I think its more difficult, and on later models they revised it to bringing the core out through the top rather than from below.