Hey, first time posting. I just recently bought a 90 SE. Now that the weather is getting warmer i have decided to convert it over to r-134. I have a set of gauges, and I have evacuated a system and refilled before. Know how to test for leaks and all. My question is when refilling with r134, what pressures should I be looking for. I decided to buy my own gauges and one set goes to 250 psi and the other 450. Was just needing to know if i should spend the extra money for the higher pressure.

Also, just out of curiousity, what is the diffrence between a SSE and a SE?

If you have a large fan in front of the condenser, car at 2000 rpm, high side should be 2.2 - 2.5 x the outside temperature in F.

well, If I am not mistaken, if your car wasn't originally r134 then it will ruin your system. I think they started using r134 in '95 or '96, somewhere around there. I cannot answer on the psi question, for I have never done that before.

The difference of SSE and SE is that SE is the lower end trim model of the two [I am pretty sure the base trim model is LE]. SSE will have buckets in the front and a bench in th eback [leather of course]. There is a better Driver Information Center [the SE has just a few lights and and a few less features warning you of door ajar and low washerfluid and maybe one or two more functions] SSE has a digital display, displaying all the SE has plus a service reminder, to remind you basically when the car needs service [user inputted, it just counts down milage] There will also be a better audio system [probably just a better head unit]. Thats really about it, if anyone would like to add to that please do.


-justin

Our '90 Bonne was converted to R-134A about five years ago. Just had to replace the evaporator but that was a corrosion problem. If done properly (evacuate, flush, evacuate, fill) so that all of the R-12 oil (which is what is incompatible) is removed, the system will work very well.

I now have three cars (88, 90, 92) that have been changed over and all work well in central Florida.

Most people just check the low side so 250 psi guage is adequate. High side can run to 300 psi. Proper pressure depends on the air temp but the low side should be in the 25-45 psi range at a fast idle at 85F.

One key is that less R-134A is used than R-12. If the same amount is used it will not cool well and pressures can go through the roof. A proper retrofit will have head pressures about 10% higher than R-12 & is well inside the design limits.

If in doubt, ask a professional but conversions are very common today.

Thanks for the help guys. This is just the first thing on a long list of things I am going to do to this car. I am quickly becoming a bonneville lover. Anyone know where I can get the service manual for it though. Only found one on ebay and forgot to bid on it before it ended.

Yes you can convert this car over to R134a. These things have to be done or you will be doing it all over agin soon!
1 All lines need to be blown out real good. Also blow out the condenser and evaporator coil. Change all the O-rings you can get to.
2 Remove the compressor and drain the oil. Turn it over a few times by hand while holding it upside down to clear all oil out. Change those O-rings also. Refill with 4 ozs of new Ester100 oil. Put it back on the car while trying not to spill it. After lines are connected, turn the compressor a few times by hand to clear oil out the cylinders.
3 Replace the orfice tube and the accumulator. Put 2 ozs oil in accumulator, other 2ozs goes in the condenser or wherever else you can get it in. Immediatly after putting the oil in and changing the accumulator, pull a good vacuum.
4 Recharge with 80-85% of the original R12 charge with R134a. Mine came to 32ozs. This should be weighed in for accuracy.
5 Enjoy your cold A/C
I hope I didn't leave out anything. This is how I converted my 87 over last month. Compressor had fried. Got lucky flushing out the condenser.