A/C not cold on '91 300E>>

[nissanzx1]

Hi guys, I have a '91 300E that has been converted to 134a. I have had the car for a couple years plus, and the a/c has always worked great. Now it's just slightly cold. Compressor sounds like its turning on fine.

I am handy, but know nothing about automotive a/c systems. Where do I start? I am on a budget and would like to try something myself before bringing it to a shop.

Thanks for any advice...

-GH

[pifcat2]

buy a diy recharge kit with the gauge. It will indicate if it needs more gas or if it's another problem...

[david s poole]

with 134 the system only has to be a little short to impair the cooling performance.a converted system also will not have had the hoses swapped for barrier hose so it will lose refrigerant slowly---add a little every year.

[nissanzx1]

Okay, I feel stupid. Recharging the a/c was simple. Got myself one of those handheld machines and a can of R134a, and it was a breeze. A/c is back working great and just in time. Total cost was only about $50. Hopefully I don't have any major leaks...

Also had really squeaky brakes on the 300E and fixed that today as well. I got some of the Benz brand break pad paste and put in new wear pad sensors. Squeaking is gone at least for now...

It has been a good day. Thanks guys!

-GH

[tarheel75]

I have a 92 300E that I had converted over to 134a in 2002. About every other year I have to have can added. I had new hoses put on at that time but I think that there is a sloooow leak through the compressor. Question, where is the valve to add freon located?? You had brake pad noise which you fixed with grease. I have a left front rattle that sounds like a front bumper or whatever when I go over a small bump. I just replaced my front shocks and couldn't find a tie-rod or stabilizer problem. I've had my shop put it up on a hoist and tried using a rubber mallet and had no luck??? An suggestions from cyber space????

tarheel75

There is no valve for adding freon. Strike that, R134a is not freon. Freon was a trade name for R12. Use a manifold set connected to low and high side and monitor both. Charge through the low side.

DO NOT USE A DEATH KIT!!!!!!!!!! This is the cheapie green zone, red zone gauged can from your local store, referred to in this thread as a DIY kit. Monitor BOTH sides and charge properly. If there are questions, take high and low side readings and post them here along with ambient temperature.

[Matt L]

Suva is the name for DuPont R134a.

[jwhughes3]

Originally Posted by tarheel75

I have a 92 300E that I had converted over to 134a in 2002. About every other year I have to have can added. I had new hoses put on at that time but I think that there is a sloooow leak through the compressor. Question, where is the valve to add freon located?? You had brake pad noise which you fixed with grease. I have a left front rattle that sounds like a front bumper or whatever when I go over a small bump. I just replaced my front shocks and couldn't find a tie-rod or stabilizer problem. I've had my shop put it up on a hoist and tried using a rubber mallet and had no luck??? An suggestions from cyber space????

tarheel75

I would be checking the control arm bushings as they are likely the culprit - loud bumps when going over speed bumps - sometimes sqeaky suspension noise is the symptom, but eventually they require replacement - you can just replace the bushings without replacing the entire arm at a reasonable cost.

And if you do 1 side do both.

John in San Antonio

[tarheel75]

What is the best way to check the condition of these bushings short of disassembling the entire suspension assembly?? Thanks for you suggestion.

tarheel75

[tarheel75]

I forgot to ask is this a DIY or is it a must shop project. Does it take any special tools. Replacing the front shocks was a no brainer? The rattling noise can be created by going over street center line reflective marker. There is no squeaking sound just a rattling.

tarheel75

[socaleuro]

Tie rod end?