The floor looks good. As for the hoses, the ones of the side of the firewall that I can see appear to be fine, but trying to look on the other side of the firewall proves to necessitate removing a lot of the dash to get to the heater core, to the point that I gave up half way through trying it because it was taking so long, so I’m not 100% sure of the condition of the heater core or the hoses on the cab side of the firewall.
My car came with the owner’s manual, and I’ve acquired the ford service manuals from the time. When I got the car, it had a coolant leak that had been probably leaking for 10+ years, so the coolant was almost completely gone, so it’s basically all fresh stuff.
I disconnected both of those hoses that go through the firewall, & hooked up a garden hose to one the lines & flushed the heater core out through to the other line and into a bucket. Then I flushed it in the opposite direction for good measure. I did this job on my truck a few years ago, wasn’t an overly complicated thing to do. You could try that method, accomplish two things at once, flush out the heater core, and get some idea if it leaks or not. Since your floors seem to be in good shape, you might get lucky and the heater core actually isn’t working.
Also, try using a flashlight and mirror to see if you can spot where the hoses connect to the heater core. There’s just two connection points is all you need to see. With some clever optics you might be able to see what you need to see without taking the dash apart. Removing the glove box might be helpful when doing this. Also, this might be an opportunity to purchase one of those cool vdo inspection cameras. I think you can round one up for under a $100, might be a good investment, as they come in handy for all sorts of diy’er projects, cars, and home projects.
Might suggest you acquire the book “Fix Your Ford”. Many public libraries carry it. Covers all Fords from around 1965 to 1976, sort of from the time they switched from generators to alternators until the time they switched from carburetors to fuel injection. I have specific service manuals for my Ford truck, but I find “Fix Your Ford” pretty useful for general Ford-fixing problems like this one. Best of luck.
Classy?
Yes!
As to their driving dynamics, all I can say is…Yikes!
A co-worker of mine had a nearly-new Mark IV, and she insisted that I drive it one day when several of us were going out for lunch.
Little did I know that–in contrast to my Volvo–the brakes on her Mark IV were merely…suggestive…of a device that would actually be able to stop the car.
After 20 minutes behind the wheel of that VERY badly-handling car with drastically undersized brakes, I decided to never again get behind the wheel of her Mark IV.
My 3 year old Volvo had all kinds of other problems at that point, but its brakes were so far superior to those on her nearly-new Lincoln that they were just in two entirely different categories.
@VDCdriver … Do you know if the old Lincoln you drove had power brakes? My truck – no power booster and drums all around — takes a good deal more pedal effort than my power booster disk-brake equipped Corolla to stop, but the truck stops ok as long as you press on the pedal robustly.
@VDCdriver and @GeorgeSanJose My Mark IV has 4-wheel ABS disk brakes, and they work very well. It is a 5200 pound car, so it certainly isn’t super easy to stop, but I’ve never really had any issues. My understanding is that my car is among the first to feature this (to the point that they weren’t even called ABS).
Of course it did!
Power brakes, steering, windows, seats, etc., had already been standard equipment on Lincolns for several years by that time.
The brake pedal was very easy to push, but the brakes were just not up to the task of stopping a heavy car with 5 people inside it.
I imagine that, with just the driver onboard, the brakes were probably…okay.
Probably not great, but…probably barely adequate by comparison with my Volvo.
However, with 5 people on board, the brakes were so ineffective as to be…scary.
Well, then please make sure that you never sell that car, as it is apparently the only '76 Lincoln in existence with 4-wheelABS!
Yes, your car has ABS, but it is a very early version of ABS, and its ABS mechanism only controls lock-up of the rear brakes.
Chances are good the heater core leaks, that’s a common problem for a car this old. Given all the features of a Mark IV, I’d hate to be the guy that gets to take apart the dash to get it out…
There’s a Haynes manual for it, you might see if it’s available at the library. It’s $20 for an online version. You might also look for YouTube videos.
Good post Nevada. That’ doesn’t sound too bad at all. Since the OP is an 18 year old student, while they have not much in the way of money, they’ll have plenty of time to get the job done. So OP, take it slow and easy and you’ll have your heater working in no time I expect. And the good thing about this job, if you get stuck halfway through the job, no problem, you can most likely still drive the car.
So I tried the garden hose test, and I noticed that the water didn’t seem to be flowing almost at all into the supply line. I noticed that the supply line seems to have a vacuum-controlled valve near where the supply goes in, and it seems that even if I set the temperature to the highest possible setting (my car has ATC, so I don’t have a direct option to turn on the heat), but the valve does not open. It seems that when the car is on, the valve can’t easily be opened manually (but when the car is on, it can), so it seems that the vacuum does seem to be functional. Does this perhaps suggest a problem with the ATC? I noticed the AC compressor engaged no matter what I set the temperature to, but above around 70 degrees, I heard what sounded like some vacuum-related thing opening or closing.
So I’ve purchased the heater core, and I’m working on installing it. As far as I can tell, there is a large cover over some component of the AC system, and over the heater core:
I’ve taken out all of the bolts holding it together, but I can’t seem to get the cover off. I’ve noticed there is this bolt on the bottom left corner of the left half of the cover.
Being a senior in high school, I don’t have a super big budget for car repairs 
