Captain Obvious

LOL. Hello? Is this thing on? Check your VIN. Is it a CA car? All this stuff I wrote here is incorrect. Registering it as a classic will exempt you from the emissions inspections. Both the visual and the enhanced. See post further down for more detail. I'll double check when I get a chance, but registering it as a classic won't get you out of the visual test. The visual is part of the annual safety inspection. Registering it as a classic would get you out of the enhanced emissions test, but that is moot... Due to the year (1975) you are already exempt from the enhanced emissions inspection.

Agreed. And even if they did, I'm not sure they know what a CA spec car is even supposed to have on it. I mean, in CA I bet they would know. But in PA or NC, I'm not so sure. I've got my PA mechanics inspections license, but back when dinosaurs roamed the earth (when I first got it), I don't even think there WAS such a thing as an emissions inspection. And I'm not sure how detailed the pics and guides are for the older cars. Unless the old curmudgeon mechanic happens to remember what was supposed to go where, I don't think much of anything would fail a visual only inspection. Pretty much everyone would recognize an EGR blockoff plate, but other than that, I don't think any freshie mechanic would know what they were looking for. Can you imagine some thirty-something at Pep-Boys sticking a head up under the dash looking for the altitude switch? In other words... I'd fail the crap out of the thing, but I know what I'm looking for and I'm clearly in the curmudgeon category.

What he said!!

That's not the altitude compensator. That's a vacuum delay device for the EGR. The altitude switch lives under the dashboard above the driver's knees. But regardless... Other than wiring harness changes, the CA differences can be pretty easily removed if someone really wants to. But according to the FSM, the CA spec should be built into the VIN.

So, first of all, if you have the car registered as a classic or antique, you don't need emissions testing at all. Second is, if you drive less than 5000 miles per year, you'll be exempt from the (enhanced) emissions test, although they are always required to perform the same visual test even if you're below the exemption threshold. I checked the dates on the current regs and it goes like this: The subject vehicles registered in counties in the Philadelphia Region will be required to undergo the following tests: 1975-1980 vehicles - One-speed idle test; gas cap test; visual inspection And the visual inspection goes like this: (d) Visual Inspection of Emission Control System. (2) Provided that the make and model year of the vehicle would have originally been equipped with the device, reject if one or more of the following apply: (i) The catalytic converter has been removed, disconnected or is the wrong type for the certified vehicle configuration. (ii) Exhaust gas recirculation (EGR)valve has been removed, disconnected or is the wrong type for the certified vehicle configuration. (iii) Positive crankcase ventilation (PCV) valve has been removed, disconnected or is the wrong type for the certified vehicle configuration. (iv) Fuel inlet restrictor has been removed, disconnected or is the wrong type for the certified vehicle configuration. (v) Air pump has been removed, disconnected or is the wrong type for the certified vehicle configuration. (vi) Evaporative control system components have been removed, disconnected or is the wrong type for the certified vehicle configuration So the bottom line for the 280's are... You need an EGR, PCV, and the carbon can. And if the car came with a catalytic converter, you need that too. The 280 never had a fuel inlet restrictor or air pump so those don't apply. But there is no functional test for anything other than the gas cap. It's all "make sure it's still there" kind of thing. So still, the biggest thing you need to do is determine if your car was a CA spec or not.

Killian, If your car was originally sold into MI, then if did not have a cat from the factory. And as mentioned above, the first easiest way to know if your car was a CA spec. And about the PA inspection rules... It's been a little while since I dug into the requirements, but last time I checked, 75 would have a "visual inspection" only. So your note about "equipment on and working" is a little more restrictive than necessary. If I get a couple cycles, I'll refresh my details on the inspection regs, but my understanding is there are no tests to determine if anything is working. It just has to be present. Some things often removed on a 280? Top of the list would be EGR valve and controls. Second on the list would be the carbon can. And that's about it. BTW - We're probably pretty close to eachother. If you're interested, shoot me a PM!

Yeah, since most of us here (including the OP) aren't running Wilwood stuff, then that datasheet is pretty much moot About the only thing that Wilwood data sheet did for me was confirm that "residual pressure valves" are really a thing, and (for me) raised the question of "Is Wilwood the only people who do this, or does everybody do it?" And after some digging "on the internet", the answer appears to be "everybody does it and have been doing it for decades." So my bottom line takeaways from all this are pretty much identical to yours... Some sort of residual pressure valve is a good idea if you are running drum brakes with return springs*. And if you are running disk brakes and have your master cylinder mounted lower than the calipers, you should also use one, but it should be a lower pressure rating. There could easily (probably?) be a difference between F and R outlets on the stock master cylinders and there could be issues if you don't account for that in some way. I think we're all on the same page! * I can get into my take about the "why" if anyone is interested, but not sure anyone wants to hear it at this point.

Haha! Yes, of course I did. And I found it completely lacking any explanatory detail whatsoever. In that data sheet there was one statement of fact with absolutely no explanation as to the WHY the situation exists. It said "This master cylinder contains internal residual pressure valves for drum brake use only which should be removed and not used in disc brake applications." Well that's great, but so what? So Wilwood puts a valve into their aftermarket master cylinder. Got it. But I want way more than that so I dug around to figure out the theory as to the WHY and I found (what I consider the best, most well explained and credible) info at that link I pasted above. I'm just trying to provide some clarity as to the WHY they are in there because I believe understanding the issue might be the first step in coming up with alternatives. So with that in mind... How about swapping the check valves between F and R instead of the hard lines? Wouldn't that fix any potential issues for the people who want a different solution other than bending the hard lines?

Haha!! Well glad that things got worked out at least enough that work can resume!

Labor disputes with management?

I took a quick look on the web and came up with this. Seemed to be the best detail of the situation(s): https://www.jalopyjournal.com/forum/threads/tech-brakes-residual-pressure-valves.74978/ After reading through that, I'm not buying the "return springs" part of the theory, and I'm all in that the residual pressure is required only to prevent sucking air into the system at the wheel cylinders. But of course, I'm just a guy who read it on the internet. I've got a master cylinder here that I've taken completely apart, including the outlet valves. If I can find it, I'll see if I can determine any differences between the valves from F vs R. Of course, when I took them out, I didn't bother to mark which is which, so...

Here's another link that talks some about the internals of the master cylinder and the possibility of switching the front and rear lines. https://www.classiczcars.com/forums/topic/66168-brake-master-cylinder-identification/

Correct. With the original system the only location exit for air-conditioned air is the dash vents. There is no way to get air-conditioned air to blow directly onto the windshield for defrost. Other complications include... The system (being so much smarter than you are) automatically blocks all water flow to the heater core when you switch it to defrost. So it's not like you could even blow hot air out the defrost vent at the same time you're blowing dehumidified cold air out the dash.

I did some digging on-line to try to find good theory description info about that little capillary tube and didn't come up with anything great. I'm probably just not using the right search words, but I couldn't find anything I'm comfortable linking to here. I found stuff, but nothing good enough to link to. My read on the design is the capillary tube is filled with "something" (either a liquid or a gas)* and it's job is to provide some regulation of the temperature of the air coming off the heater core. As the temperature of that coiled tube heats up, the fluid inside expands and will push the little piston out at the far end and that will (depending on the position of the temperature control slider) close down the valve some amount. Been a while since I looked at it in detail, but memory says that sensor/piston device can only CLOSE the valve. It cannot open it. Memory also says that sensor/piston has a limited range of effect on how much it is able to close the valve. I think if the slider is moved to full hot, that sensor has no effect. And since the sensor/piston can only close the valve and cannot close it, it has no effect when the lever is on full cold. It only provides some temperature control between the two extremes. * I found sources that say "freon", "ether", "alcohol".

Same thing happened to Spinal Tarp. Suuuuuuuuure they were.

OK... You got my attention. Nice pics! So your car is a 75 or 76, right? Someone who really knows what they're looking at would probably be able to nail the year just from the pics you posted, but that's not me. Couple thoughts on your original question... First, the EFI system is wired pretty much independent from the rest of the car. There is one sub-harness that does nothing but EFI and the rest of the car will pretty much function normal whether that harness is installed or not. So I'm thinking the work has been done for you already. Just put the stock stuff back with the exception of the EFI sub-harness. Second thought is if you're looking to strip stuff off the car (I see you've removed the mounts for the CARB can and the A/C controls) and you want to get that stuff out of the wiring harnesses also, maybe you could just open up the originals and take out what you don't want and then re-wrap?

Couple pieces of input. The metal end-cap on the heater core where the inlet and outlet tubes are attached should just pull off. If you're going to send the core out, don't send that end cap. It's just one more piece to get misplaced along the way. And as for the tube coming out of the valve... Yes, that's an automatic temperature compensation feature that is supposed to regulate the temperature of the heater core. There's supposed to be compressed gas inside that capillary tube (freon maybe? Nitrogen maybe?) that expands and contracts with the temperature and opens/closes the valve accordingly. But, that said... None of that probably works anymore. The gas has probably leaked out, and the valve has probably either frozen up solid inside, or the seal inside has turned to dust and dissolved into the coolant over the years. In any event, I would be very surprised if that valve is any good at all.

Doing movie reviews? "Interested.... Interested.... Very interested.... VERY interested. Then suddenly lost interest."

3000 to one, huh? Bring it on!! Haha!! Happy New Year everyone!!

Two thoughts... FIrst, they used the same control arms on both sides of the car, so you don't have to look for a "right rear" arm... Any rear arm from either side will work. The later years will work as well, but there are some small (I believe non-functional differences). So unless you're looking for concourse correct for your year, then I believe any year will work*. Second, I've got the original arms off my 77. The PO did some damage to them when he pounded the old bushings out. Not nearly as bad as what happened to yours, but they're not pristine. They annoyed me enough that I replaced them when I redid all my suspension stuff. But if you get stuck, they're yours for the cost of shipping. *The really early cars might be different as well, but I have no experience there. And with the cost of anything really early shooting up, it's unlikely you'll turn one of those up anyway.

Hope the tank works out! Do you have a pic of where it was leaking?

Rather than taking the bowl covers off, you could just pull off the vent line and stick something down the hole and see if it comes out wet. Like testing a cake.

@Mike

Well I'm no brake expert, but I certainly appreciate the callout. With that in mind, here's my read. I agree with Zed Head that since the bore and stroke is the same, everything would be the pretty much identical when you pressed the pedal DOWN. However, I'm less confident that everything would be OK when you let the pedal back UP. There are check valves built onto the pistons inside the master cylinder and there are also check valves screwed into the outlet ports of the master where the brake lines exit. I haven't studied any of it in great depth, but there is no guarantee that the characteristics of each pair of check valves are the same. You need to make sure that when you RELEASE the pedal, you never create enough of a vacuum out at the ends of the system such that you would pull air backwards past the wheel cylinder or caliper seals into the brake system. Those check valves are all a balancing act between the return forces at the destination ends and the vacuum created inside the master cylinder chambers when you let up on the pedal. And since one chamber is filling large calipers that don't have any return springs while the other chamber is filling small wheel cylinders that DO have return springs, I could be easily convinced that the smart people who designed the master cylinder knew that and designed different check valves for each circuit. So, what could go wrong? When you let off the pedal, you could suck air in backwards past your corner seals (wheel cylinder or caliper). This could make it hard to bleed the system, or even worse, it could cause spongy brakes if it happens under normal use. Or it could all work out just fine.