Cascade Crew

[chevymad]

Seems like I have to go back to work to rest up anymore. Always yard work to do, and it seems like the lawnmowing has become perpetual. Mowed monday through wednesday, and started on it again yesterday, yuck!

Anyway, still managing to get some things done. I put a new a/c compressor on the formula, then retro'd it to r134 while I was at it. Took the throttle kicker off the 454 and put it on the quadrajet i'm runnin on the bird. Then rewired the relay so it worked right without ecm control. Nice and cool now!

Today I decided to work on the truck. I posted pics quite awhile ago when I put a z28 rear bar on the back of the truck. Then after I lowered it and added an air bag kit so that it could tow again, there wasnt room for the bar anymore and it had to come off. Jacked it up today and played around till I figured out how to put it back on again. Truck drives sooo much better with it. Takes alot of the flexy feeling out of it. Smooths things out somehow too.



What I did this time was cut 2" out of the middle of the bar. Then I ground the ends down to points like a limb a beavers gotten ahold of. Then welded it together in layers. This narrowed it enough that it fit underneath the rear this time instead of on top. And the air bag mounts became good places to mount the end links. I had to lengthen the links. Didnt have any 10" long 3/8s bolts so I made a couple. Had some 3/8s rod, I just cut it to fit and threaded it. Then cut the spacers out of galvanized pipe. Seems to work well anyway.


While I was under there I happened to notice that the old chevy didnt escape with no damage from pullin "somebodys" dodge off the beach. Check out my hitch's chain loop! Wouldnt have thought you could pull that hard on sand with a 2x, and I didnt think I was getting that hard a run at it either.



So whats everybody else up to?

[Mangus]

how did the change to R134 go? Can you give a few details on your personal experience with this (I know, there are articles on how to do it). I need to do this to my TA. Hasn't had pressure (R12) in it for about 3 years. Need to get a new compressor (and any other parts you suggest), so I might as well go to R134 too.

M

[chevymad]

Actually, I'm a/c certified and have done plenty of retro's at work. There are many ways to retro but here's what I like to do. First you need to drain the compressor and change the oil. If you're changin the compressor your good there. New compressors dont come with any oil in them anymore, because they dont know what fluid you might be running. For retro systems I use Ester 100 oil. 8oz in our cars. Pour 4 oz in the intake of the compressor. You'll also need a new accumulator/filter, theres a dessicant in there that goes bad as it absorbs moisture. Even a new one will be ruined if left open more than 15min. Pour the other 4oz of oil in the accumulator. Change your orifice tube, its cheap and it usually catches alot of debris. With my car I bought a variable orifice which costs more but is supposed to give better cooling at idle. This is my first experiment with it. I also used a low pressure switch that is set for r134 pressures. Both these things arent absolutely necessary but will make it work better. You dont need to change o-rings, unless you've disturbed them. You also dont need to change hoses. If you buy a retro kit, it'll have the oil, o-rings, fittings, and labels.

You mentioned needing a new compressor, did it blow up? Hope not. Mine just started leaking and lost pressure out the front seal. If the compressor actually blew up though, you'll have debris scattered throughout the system. The orifice tube's screen is as good place to look. Alot of the debris will be caught there. If theres any, you'll need to have the evaporator/condensor flushed or replaced. Otherwise you can say goodbye to your new compressor.

Also, the orifice tube goes into the lower line in the evaporator. Mine did not want to come out and I ended up cracking the evaporator tube. Turns out this is a common problem. The bracket for the accumulator attaches to this line and bends it. They make a repair kit to take care of it. You cut the tube off the evaporator and a new one clamps on.

When you get all this done, you really need to have somebody apply a vacuum to the system for a good 45 minutes. This will remove any remaining moisture in the system. Moisture and the lubricant make acid. So you dont want that. If the system holds vacuum thats a good sign theres no leaks too. Then you can refill the system with 90% of the original r12 charge. You dont need as much r134.

I know some guys just squirt in r134. But you'll give the next tech a headache.. and possibly ruin his bottle of refrigerant if he drains yours into his. I also dont think it'll last long. The main reason is the oil. r134 will not carry the original oil through the system. Thats why you have to change it. If you just add the new oil to the system then you have twice as much, and no where for it all to go. Each component in the system holds a certain amount of oil. There are several different kinds of oil that work with r134. But Ester is the only one that'll mix with any remaining mineral oil in the system. Also stay away from a/c stop leak. Moisture is what makes the stuff harden to plug any leaks. If there is any moisture in the system(there will be eventually) the stuff starts turning to slime. The compressor can't pump slime.


Most of this can be done yourself. You probably wont have access to a vacuum pump but that part shouldnt cost much to have done. Then you can either have them fill it or use the pound cans and do it yourself. It works fine when you're all done.

[Mangus]

excellent info, thanks.

[Schultzy89GTA]

Nice B. Awesome write up too.

-Schultzy

[85 T/A WS6]

I dug this one up, I too will retrofit soon.

I have a new compressor. From what an A/C tech has told me, if the oil I drain out of the old compressor (shaft seal failure) is clean I should not have to replace the dryer and orifice tube. Would you agree?

Also our other T/A smokes, I dont know if its rings or valve guides. It is white smoke. Is there an easy way to tell? I really need to get this project done and would like to rebuild the HO. I did consider a crate engine but changed my mind.

They only made 1600 or so 85 T/A HO's (All 5 speeds)

Thanks,

Don

[chevymad]

Don change the accumulator. They contain dessicant that absorbs moisture. This stuff really only lasts about 2 years in a closed system then its done. Moisture + refrigerant +oil = acid. If you leave one of these things uncapped for 15 minutes theyre used up as well. Last time I went to a seminar on a/c they were saying the accumulator/filter really ought to be a routine maintenance part.

The orifice tube is really inexpensive. If you buy a variable orifice or one set for r134 you'll have better cooling then just using the old R12 orifice.

As for the smoking, it's hard to tell with catalytic convertors on cars now days. They burn most of the smoke. But if it seems to smoke mainly on the downshifts or startups then its guides. If it smokes worse going uphill or underload its rings(or all the time). Oil smoke should have a bluish tint to it. If your burning coolant its white smoke, and if its too much fuel its black. But catalytics make this hard to tell.

[85 T/A WS6]

Thanks Brandon