Rambler65

Propane by itself will result in too much head pressure and you'll probably wind up blowing a hose or damaging other components. The hydrocarbon R12 replacements like Enviro-safe and Duracool mix in isobutane to keep pressures under control. I'm not sure of the percentages used.

Rambler65

Your old R12 drier won't be compatible with R134. Any new one will be unless it is old stock that has been sitting on the shelf for over 20 years.

Technically the drier should be changed whenever the AC system is open to atmosphere, though if open for just a short time you can usually get by with just pulling vacuum a bit longer.

Moisture is a bigger problem with R134 because it forms acids that wind up eating microscopic holes in your evaporator and other metal parts. The oil used in R134 systems absorbs moisture from the atmosphere about 1000 times more readily than the old R12 mineral oil and it is not removed by pulling vacuum, so you want to be careful about that as well; only use a fresh/sealed bottle of oil put in just prior to buttoning up the system.

You can also install a new expansion valve calibrated for R134 to get a little better performance than with the old R12 valve.

The results really depends on the system being converted. R12 systems that have excess capacity work quite well, sometimes you can hardly tell the difference. Systems that are marginal with R12 will yield a noticeable loss in cooling.

BTW, the worldwide safety record for hydrocarbon refrigerants is actually very good. They have been used overseas for many years, even in household appliances. The stuff dissipates really quickly when there's a leak. You obviously need to be careful working with it, treat it like working on the fuel system. (Remember that the mix of R134 with oil is also flammable and it yields toxins when it burns. In fact R134 with a lower flash point is used in flash bombs!) There are "demos" floating around purporting to show horrible explosions with hydrocarbon refrigerants but every one I've seen has either been rigged or the participants were doing something really stupid.

In the U.S. the problem with HC refrigerants is primarily legal. The EPA says it is illegal to retrofit them directly to an R12 system, but legal to do so with an R134 system. So if you convert first to R134 then you can convert to HC. (Typical bureacratic BS.) However there are also state and local laws regulating their use. Additionally no repair shop will want to touch a system using any alternative refrigerant.

Rcaggiano

Alrighty. Thank you

93XJeeper

thanks, is there a way to remove and check the injectors for leaks? Also, bubbles on the dip stick are not there when I have the engine off. I'm hopefully getting insurance and the tags this week and then I'll be driving it on two 20 mile trips everyday. I got a set of 703 injectors that I plan on installing. Only problem is i only have 4 of them, still need two more.

salad

Yea, you basically pull the rail and injectors as a complete assembly and turn the ignition to "ON". Any leaks should be apparent.

Not sure what you mean by bubbles with engine off... You're pulling the dipstick with it actually running? Some small foaming is hard to avoid but we'd need a photo.

There are lots of folks here that can help you with injectors lol

93XJeeper

thanks, I'll try that. And sorry if I wasn't clear. With the the engine off, there are no bubbles, with the engine at idle, there are bubbles.

Joecam18

Would this possibly cause my rattling?

NewKindOfClown

I called it. Don't worry, no charge for the diagnosis this time

Joecam18

Now the questions is, how do i fix it if i cant weld or get a new exhaust lol

NewKindOfClown

However you can.

First thought? An exhaust clamp around the pipe there, a bolt through that rubber hanger with a washer on each end, and use steel zip ties to hold the clamp and the bolt together.

If you wanna be fancy, get a longer bolt and use two fender washers on each end with a nut between each pair. You could loop the zip ties around those nuts, between each pair of washers, so you don't have to worry about them slipping off.

I suspect it would hold for a while, but it may allow enough play to continue rattling.

Joecam18

Thank you sir!

gigemjeep

Bump. Btw, 99 4.0 XJ if that's necessary.

XJ=mistress

Theres a few threads on here that have lots of info on that.

Basslicks

Didn't they switch to an electronic speedo sensor around that time or was that just on the WJs?

FANTASTIC! Thanks for the information there. Good thing about what I'm going to do - er well, attempt so long as the system is in good condition - is swap the aforementioned components from the 96 parts heep I have onto my 92. My grandfather has a vacuum pump and the refrigerant gauges so the only challenge is going to be keeping the drier and compressor sealed until I can drive out there to swap them.

EDIT: After MONTHS of searching, I may have just diagnosed my problem to an overcharge. According to http://www.youfixcars.com/air-conditioning-noises.html ,

"A buzzing noise from the compressor when the air-conditioning clutch is engaged is often a sign of an overcharged system. In this scenario the buzzing sound is caused by liquid refrigerant entering the compressor.

Of course, this condition is most common after an air-conditioning service when too much Freon has been added. If this is the case it needs to be corrected as soon as possible, because it can damage the compressor. Also note the AC will not cool properly when it's overcharged."

I'm going to remove some of the refrigerant from the system and see what happens.

Rambler65

What I would probably do in a case like that would be to leave the new compressor and drier factory sealed until you get to where you'll be working on it. In particular the drier should not be left open for more than a few minutes if at all possible. You might also want to consider getting some Nylog to use on the fittings, I've found it helps quite a bit in getting a good seal:



(Nylog blue works for R134 systems, Nylog red for R12. It's more of a matter of compatibility with the type of oil used, so if you were going to say use an alternative refrigerant and stick with R12-type mineral oil you would use Nylog Red.)

When installing the refrigerant oil you want to put the proper type and amount in the compressor as specified by the manufacturer after dumping out any old oil (or shipping oil if new). Put the rest required by the system in a couple of other places to distribute it. (Usually I'll put some in the drier and some in one or two of the hoses.)


A noisy compressor can definitely be caused by overcharging but I would not expect this to be the case unless more refrigerant had been added recently.