My 1987 Mercury Colony Park

[TecNickal]

Much better to enjoy a birthday tinkering under the hood of a fine Ford motor company product Thanks again for spending the day here.

Look forward to the heater core job on this car in the future!

Security torx is a funny name for a fastener that you can buy the proper tool for...

[friskyfrankie]

Heater core jobs on these cars are NOT fun! With all the old plastic and vacuum lines I would REALLY test everything prior to putting it all back together again. You really don't want to go in there again. As an aside, a few years ago, I was watching a video of two guys up maybe in Tenn. that did the job in like 1.5 hours but it looked like they took several short cuts.

[gadget73]

not that many vac lines involved honestly, its just a miserable job pulling the dash loose.

Pressure test the heater core before it goes in. I put in an OE Motorcraft once that leaked right out of the box. Had to do the job again a year later when I could no longer put up with the smell. The second core got cobbled up with an air pressure regulator set to 15 psi and whatever hoses were around to connect to it. The other side I just jammed my finger into the outlet to plug it and stuck the thing in a bucket of water. If it leaks, you'll know it pretty quick. Annoyingly the Motorcraft wasn't just a cracked solder joint at the pipe, it was actually leaking from a tube inside the core. Not practical to fix that.

[Kodachrome Wolf]

Heater core got here surprisingly quick, ordered it Monday.

Looks like the box went around the block a few times:


Original Ready-Aire sticker was redone with an OSC, then superseded to a Four Seasons part number (399002 → 98620). Maybe if I'm careful I can peel away the old stickers and see when it was boxed.

Listing showed an aluminum replacement, but given all the relabels, a more traditional brass/copper unit appeared instead.


I'm also considering using a different heater core restrictor. I've got an appropriate sized socket jammed in the hose, but that mod wasn't done until the HO swap was done, and I still regularly would open up the car, so I dunno if the core started to go then, or after. I can grab a LMR Mustang one if I really need to since I'd like to extend the life of the core and I'm not sure how well these cores handle pressure compared to an aluminum one.

Quaint reminder that a LoPo blew apart a "off-the-shelf" inline restrictor for Chrysler vans...



I will certainly pressure test the core before any installation is attempted. No fun doing certain jobs twice, and having already done a heater in a '99, it's certainly worth doing right the first time.


Unrelated to installation and more-so just reading stuff online: Should I be excessively worried about electrolysis in my system? I've been using conventional green antifreeze (due to be changed next year given the 2yr/36K recommendation) in this particular application, however, some people claim aluminum radiators and brass/copper heaters don't play well. I've converted my '97 to the Zerex G-05 gold antifreeze without any issue, and it was also a conventional green car, but carries an original aluminum radiator and heater. I am familiar though that it does offer better protection even with dissimilar metals. Since I'm already due for a flush-n'-fill, would anyone be dissenting regarding just converting to a later coolant like G-05?

[gadget73]

shouldn't be a problem but it might be worth doing a voltage check to make sure nothing funny is going on. Where you have to worry about is where things have an electrical connection. The core isn't tied to anything, so as long as the coolant hasn't gotten funky it won't really care.

[Kodachrome Wolf]

Went up to Nick's yesterday and we knocked out the heater core swap.



Dash drop was reminiscent of that '99 I did last year, just the "magic stud" changed spots and was below the instrument cluster directly above the steering column. Took only about an hour and a half to get the dash down. Firewall stud didn't even really fight us much.

Someone has already done a heater core on this car, and I managed to somehow get the exact same brand and style of heater core.


I definitely ballooned this core.




Certainly made it a little more fun trying to pull that out of the heater box.

No idea how long the old one was leaking in my case. For the longest time I'd get a slight whiff of antifreeze usually the first time I'd start using the heater, and it would go away. Same thing would happen if the car was parked for several days and you first turned on the air, just a slight whiff. Antifreeze loss was so slow, I just chalked it up to the car being the way it was. I just knew the game was up when I goosed it one day and steam started coming out of the vents and then stopped.

Anyway, that 13mm socket "restrictor" is still in place on the inlet side. Heat is great again. Didn't find any leaks, so I'll take it easy on this heater, at least until it's warm outside again. I did install a manual shutoff switch. Not the prettiest thing, and I'll probably have to move it out of the way when I do spark plugs and such, but I suspect it'll be useful in summer to help the A/C not contend with all the heat.



I had wanted to find a vacuum actuated style that would work in Max A/C, but a proper bypassing style one is not offered with 3/4 fittings, and I didn't want it to just stop the flow on the inlet line since I have my concerns about just blowing that apart.


Nick also had a few things for me. We swapped on a moderately better tan dash pad that has some minor imperfections, but not excessively cracked like my old one. He also gave me a very nice leather wrapped wheel that I need to try and recolor. The final part was something found while he was in the northeast:


Finally have that air deflector I've been looking for.


I've only got two minor dash things left to do. The shifter indicator I think broke internally behind the cluster bezel since after adjustment on the column, it just quit indicating properly and I found slack in the cable. Not too concerned, I think it had a crack in itself anyway and it's serviceable separately. Also need to adjust the trim on the driver's side as it picked up a slight squeak, but if you apply slight pressure, the noise stops. Overall not horrible for moving a bunch of old plastic around.

[87gtVIC]

Good deal. Nice to have help on big jobs like that. Some of this stuff just is not the same once ones hands have been into it a time or three....You will get used to the squeaks in time.

Nice score on the wind deflector.

[gadget73]

Sly did one that was vac actuated, off a Ranger I think?

can't just shut the flow off. Not because it will blow something up, but the ECT is in the heater hose fitting on the engine and if you stop flow through it the ECT will not have an accurate read on coolant temp. Makes the fuel mix all stupid if that happens.

[sly]

Yeah... Ranger/Explorer heater bypass. Hooked the vacuum into the panel vent actuator. Did that on the Mark VI. Wonder if sxcpotatoes still has that in place.

[TecNickal]

You're very welcome for the help Zach. Glad I could help. And enjoyed learning how the dashes come out on the 89 and older box body cars. Cheezy is how I would describe it compared to modern cars. The heater core bypass idea is a good one.

[gadget73]

never had one of these dashboards made of razor-sharp sheet metal and crappy plastic out before? They're a real joy aren't they?

[Kodachrome Wolf]

Sly did one that was vac actuated, off a Ranger I think?

can't just shut the flow off. Not because it will blow something up, but the ECT is in the heater hose fitting on the engine and if you stop flow through it the ECT will not have an accurate read on coolant temp. Makes the fuel mix all stupid if that happens.

Yeah... Ranger/Explorer heater bypass. Hooked the vacuum into the panel vent actuator. Did that on the Mark VI. Wonder if sxcpotatoes still has that in place.

I saw that one, but the 5/8" hose barbs turned me off. I guess I could have cinched the 3/4" hoses down over the barbs, but that really didn't seem too appealing, and I didn't want to add four reducers to 5/8 hose to run in and back out. The vacuum style is definitely nice though given the automatic operation. I did see a vacuum one for an Astro with the right sized hoses, but it wasn't a proper bypassing type. Looked like it would only cut the flow to the core, but still allow for some to circulate into the return line each way, unlike the Ford design that does a 100% return operation.

Given how usually the weather drops from hot to cold around here, the manual one shouldn't be much trouble at all, since it'll probably only see action twice a year unless something bad happens to the heater again.

[gadget73]

why do you have 3/4 hose? both ends of what it connects to should be 5/8.

[Kodachrome Wolf]

why do you have 3/4 hose? both ends of what it connects to should be 5/8.

All my connections are 3/4". Heater core and the ports coming off the intake and water pump are all the same size. 5/8" would never fit over those fittings. Even the original molded hoses had 3/4" inlets. I think the one that went to the pipe that run under the intake was an exception, but that pipe is long since gone and was replaced with bulk hose.

[gadget73]

pretty certain my heater core is 5/8. Mine has the double pipe under the intake so my hoses there are different but those are definitely not 3/4.