Hello Friends. I've started this thread as a place where those of us rebuilding our 308's A/C can share tips, pains and successes. Right now, I am in the 'study phase' as my '79 308GTB is in Tulsa and I am in Houston. I have ordered an R143a manifold and guage set along with a cheap vacuum pump. I also have the Haynes HVAC tech-book which I am studying. I am a physicist so I understand thermodynamics. The real question is, how is the concept implemented in this application. It appears that my car uses a receiver-drier system so there is no accumulator. The receiver-drier is on the high pressure side right before the evaporator. When my system failed, it was an electrical fault. I suspect a compressor clutch - or the associated wiring because I have jumpered around all the pressure switches, etc., while testing a few years ago. So please tell me/us about YOUR project. regards, rick
My failure was a hose that wore through. At the compressor, the smaller (high pressure) hose arches up from the compressor and then down behind the fuel tank on the way to the front of the car. In my case, a mechanic didn't notice that the hose was arched up so much that it was rubbing on the square frame rail above and to the right of the compressor. You can see the hole that was worn. It's a simple solution as one just has to rotate the right angle fitting at the compressor down so the hose can't touch the frame. Of course, you can't have any Freon in the system when you do this as you are opening the fitting. Image Unavailable, Please Login
Search, there have been numerous threads on this. If I can find the rebuilt thread I did, I'll post it. I put a Sanden Rotary, R134 and BMW Drier into my car (the drier fits perfect into the dryer clamp on the exising car an looks like like the Hansa unit, only $50 less money).
Just did a complete charge on my R134a A/C system and the results are iffey. I am encouraged to rebuild the entire system as time permits. rick / '79 308GTB Euro. specification, original German delivery
i re-did my evaporator box and added some additional vents. the problem with the 308 a/c is a lack of air volume-the rest of the system is sufficient to cool a much larger car. if you like, pm me and i will discuss the modifications with you.
Mine worked well, until removed........ Sean F. is the man, being in the HVAC industry and all. Your Euro car should have had a Sanden compressor as OEM? US cars had a York usually......get yours fixed, and come do mine!! LOL! My #22641 still has all components in place..probably just needs a charge..yea, sure!
Sean F. et al., A few A/C questions: + If a once working R134a system has failed by a slow leak, does it need to be evacuated before refilling? I can't see how it would be contaminated. + What high and low side pressures might one expect for a 308 running stock hardware but with R134a gas (and a new receiver-drier when the conversion was done)? Ambient being ~95 degrees F. + How much R134a might one expect to load if the pressures have dropped so far that the safety switch was tripped? All help appreciated. rick '79 308GTB
Carr Automotive parts on old Hempstead Hwy. helped Sean with his conversion components...........maybe he'll post the info.. Let's get together for a drive or something..I'd like to see your interior, one of my 1977s has blue carpets, crema leather..
Agreed! I am waiting for my license decal to arrive from Oklahoma before I can do much driving. Plate is expired by 10 months. :-( My seats and door panels are blue. Dash, console and all other trim is black. Carpet is black. Headliner is grey patterned vinyl. My silver 308 was originally Grigio (medium grey metallic). The interior is correct, as is. rick
RIP IT OUT!!! Less weight and one more thing that can't go wrong!! After all, how much hard-drive brain space can we spare when we have to worry so much about fuse blocks, air cleaner stuffing, month-long wheel bearing replacement projects, cam belts breaking every 3 months, suspension upgrades, overworked brakes, engines that run at 300 degree despite $3,000 worth (and 1,000 F-Chat posts) of "overheating" repairs.... I say again: RIP IT OUT!! FREE YOURSELF!! It is AMAZING how much all that junk weighs (and just how junk it IS). I've had about 15 or so "classic" cars and I don't think I've used the A/C in any of them (the few that actually had it). I think of the 308 as such a "sports" car, the posts about A/C always seemed out of place. (Don't flame me for sounding like a sports car snob, part of me IS coming from purist point of view, but as long people DRIVE these cars , I pass judgement on no one!!). And... I'm one of those freaks who grew up in Baltimore, MD (90 degrees with 90 percent humidity, went to college in Tucson (105 degrees), and live in Los Angeles (90 degrees today as a matter of fact) and have NEVER had A/C, so maybe it's just me. I do use the A/C in my Suburban though!!!
I'm in Houston and suffering from 'first summer in Houston syndrome'. My 308 needs air if I'm going to use it - with my wife onboard. As for the Suburban thing, I understand. My daily driver is an SL500; wife drives a Land Rover. Both with A/C cranked.
I would not convert to R134...just pay the little extra and stay with R12. The evaporator and condensor in older Ferraris are not big enough to use R134 efficiently. If you think a 308 a/c system is marginal now, just wait until you convert it to R134!
It was converted to R134a about 6 years ago. Works more-or-less okay now if starting from garage-cool. Left in the sun, it can't possibly keep up.
Now if you lose your window motors AND the A/C, you got troubles! "Just go nekkid, baby....sorry!".....
Women are funny that way. ;^) When my wife asks if I've got my A/C working, it means she'd like to go somewhere in the 308. As long as it's held a bit of pressure it won't be contaminated, just refill it. See this thread in old Fchat. It gives rules of thumb, and a bunch of links to useful A/C service info & parts sites: R134a CHARGEING/TOPPING OFF PRESSURES http://70.85.40.84/~ferrari/discus/messages/256120/105688.html It depends... Most likely between 16 & 24 oz. A full recharge with R134a s/b about 80% of the spec'd R12 charge weight. My experience with R134a has been very positive, In 90 degree high humidity weather the vent blows around 45F when I've got the charge right. In cooler weather it's down around 40F. I agree with stevegtsi, the 3x8 A/C systems main problem is poor airflow thru the airbox & vents. Pulling out the two A/C vents under the dash makes an enormous difference. Even just remoing every other vertical louver from the vents makes a big difference & no one ever notices.
I believe if 134 loses around 10% of its charge, it needs to be evacuated and new put in due to fractionation.
I have been questioning this problem also. This car I have up and running has no A/C at present as one of the hoses broke off at the fitting on the pump. Whomever installed it had to much angle on the compressor fitting and it put to much tension on the line. They also cut open the bottom of the valance panel and sorta attempted to close it up with pop rivets. That really PMO when I seen that, what HACKS!!! I have my other radiator at the shop getting cleaned and checked over and should have it back today with new shiney black paint. Hemming on if I should just take the A/C condensor off and put it in a box. Then what, do I take the evaporator out too? I have always questioned why the 308 ever had that crap in the first place. Why? Its a sports car, it should be light and simple. I dont know what all that garbage weighs but for the few days of the year someone might need it, it seems rather a waste of energy. I had this car out one day several weeks back when the temp was over 100 degrees. I highly doubt the A/C, even if working at peak efficiency would have made the inside of the car any more bearable than leaving the windows down and the vents open. I havnt seen a car yet that can cool very well once temps exceed 90-95 degrees. Any hotter and you almost have to shut it down and open the windows. At least I do.
I don't understand all of you guys with the 134a problems. If you are using the York compressor you will not get it to work well, R12 or 134a. The best thing todo is convert the compressor to a rotory Sanden 507 compressor. I have done 2 cars in Savannah, HOT AS HELL HERE!!!!. Both work wonderful. The compressor and line conversion is the must do on 308's. Joe
Is the Sanden compressor small enough to fit in a hollowed out York? If so, that would be a good solution yet keep your car looking original...
Rick, If the system will allow refrigerant to go out, in general, moisture can go in. That is one main reason for the evacuation. You probably know that moisture not compatible with good AC operation, and 134 will absorb large amounts in the gas state (after you load the system). In addition the PAG oils (one of the two kinds you can use with 134, Ester is the other) are hydroscopic as well, and creates corrosive chemicals when it combines with moisture. Not good for the little parts inside the system that make cold air. For example it is standard procedure to purge the hose of the gauge manifold of air after you connect the to the system you dont even want the couple of ccs of air/moisture in there mucking things up. You got a new vacuum pump right? Pulling a vacuum (29.9hg) and letting hold for 30 minutes will tell you that the system is sealing well enough to operate properly, and will maintain a charge. If it doesnt, find and repair the leak. No point is charging it just to have it leak out after a week. AC experts will also tell you that 134 systems cannot be accurately filled by topping up (ie monitoring pressures with gauges), and that you should evac a system that is suspected of having a low charge to give you a starting point - and fill by weight to the manufacture specs. This is a problem with converted systems. In general, with 134, you run about 80% of the R12 charge. Get an AC thermometer and put it in the center vent and add about 60% of the R12 amount (by weight). Let the system stabilize, and check the vent temp, then add one oz. Wait for a few minutes and check the temp, and pressures (cant optimize by the gauges, but they tell you how things are going). If the temp goes down- try another oz, and continue this process until you get the lowest temps. You can use a postal/ food scale to keep track of the additions. After you see the temps flatten out - stop filling it is easy to overcharge a 134 system - be patient. I guess you could do this with a partially filled system( that's what 60% is right?).. but I always like to know where I'm starting from. Some typical R134 pressures would be on the low side: 19-39psi --- 33-60degF vent temp 25-43psi --- 40-65degF 37-51psi --- 48-65 degF For the high side it depends on the ambient temp 115-200psi --- 70-80 deg 140-235psi --- 80-90 deg 165-270psi --- 90-100 deg If the clutch will not cycle on you may have to jumper to get in the first pound but it will usually not be a problem. Final comments be careful when filling. Always be sure to keep the high side valve closed when attached to your refrigerant can it can explode (165psi)! Always fill on the low side. Ive learned a lot reading the Haynes, Mastercool tech manuals and by reading up on Ackits.com (run by Arizona Mobile Air). Look for the Auto A/C info forum. Lots of info and they have AC experts monitoring and answering your questions . Good luck.. BTW my 79 308 GTB is still R12, (York) but Ive converted a few BMWs including my 735 to 134. 134 is not as efficient (about 6-8% less on a system designed for it), and combined with a marginal system it is worse. So it is worth the time to try and optimize to get the best temps. My BMW gets 42deg at the center vent with 134 and amb temp of 93deg
I tried the package approach with fairly good results. Installed a new dryer and Sanden compressor, (fabricated new mounting brackets which use original bottom bracket to support the new smaller Sanden compressor) changed to R134a with new seals , rebuilt the alternator (now has 85 amps Bosh alternator with Delco guts - more amps to turn the cooling fans faster) and installed qty 2 10 Hayden sucker fans. Also added extra heat shield between engine and firewall and wrapped the headers all the way to the exhaust muffler. Removed the original pusher fans and set them up with min amp load on bench and reinstalled. On an 85 to 90 degree day it keeps the 1980 GTB at 60 to 65 range which was 10 degree improvement over the stock system.
