In that case, in general the R4 is good for about 100K+ miles or 10+ yrs. You can try to turn the R4 comp. by hand. If that doesn't work, use a rachet on the center nut in front of it. If it won't turn then, it's best to get a new one.

Tech in general again. You might want to do a topic in tech. after that test.

 

Ah yes - switch it to high!

 

Last year when I did my engine swap and also changing my '75 over to a 4spd car, I completely changed my '75 L-82 coupe to a non-A/C car. This car is my "driver", the one I drive the most(4400mi so far this year)and has over 144,000mi on it. I wouldn't remove the A/C from a nice original car, but seeing as my '75 has no EGR, no A.I.R., true dual exhausts, no heat riser, it's far from "original". My A/C in it was virtually "shot"-hoses were split, the metal plate behind the evaporator(in the A/C housing itself)was rotted 2 inches up, compressor was locked up. I bought a '69-'77 non-A/C inside heater box, the non-A/C engine side heater core cover and a non-A/C heater core. I also purchased the correct non-A/C center bezel that says C-O-R-V-E-T-T-E below the wiper switch. I also sold the good usable A/C ducts, condensor, inside & outside A/C plenum boxes for over $300, so I pretty much broke even money wise. I also love the uncluttered engine compartment of a non-A/C car, but hey, that's me. I'm not a fan of A/C either-I have a '99 Ford Ranger & a 2004 F-250 SuperDuty I bought brand new with NO A/C.



I also had to fabricate this "L" shaped piece to accept the smaller non-A/C heater core cover & inside heater box. It came out so slick I have yet to have one person comment that I removed the A/C. Someone has to look close & even know what they're looking at to determine what I did.