What to do with the RED hose?
Well...you could just unscrew its connection at the manifold gauge and keep the hose some place clean. Use only the BLUE and YELLOW hoses. And keep the RED valve shut all the time.

Yes the recharge weight should be 950gm or 33oz. This ONLY if you recharge from zero/vacuum. But your system already has SOME R134a left so its difficult to know EXACTLY how much R134a weight ALREADY THERE in the system. Thats why you could just TOP it up and DEPEND on BLUE gauge pressure (35-45psi) to tell you that the system is FULL. Gauge pressure is your GUIDE here, worry less about the weight.


To answer your questions:
Q1: Immediately. When compressor stays ON all the time immediately shut the BLUE valve. Read your BLUE gauge now. If the pressure hasn't reach the TARGET pressure then continue recharging. Open the BLUE valve slightly again. After a few minutes shut BLUE valve and read the pressure again. Repeat these steps until you've reached the TARGET pressure (don't forget to correlate with ambient temp as R134a pressure is VERY responsive to ambient temp).

Side note:
From your description of quick compressor cycling (every 2-3 sec) I would guess you already have around 300gm in the system (this from my past experience of recharging AC in my 940). One small canister has around 340gm (12oz) of refrigerant. You need around 950gm. This means you'll need to completely empty ONE canister first. For the SECOND canister you need to recharge SLOWLY by repeating the steps above.


Q2: Long story here. In my experience the BEST refrigerant is from DuPont. SUVA is the trademark of DuPont's R134a refrigerant. FREON is the trademark of DuPont's R12 refrigerant. DuPont is US based. Another excellent choice is KLEA R134a from ICI (UK based). Ineos is another quality R134a from Japan.

The chemical molecule is the SAME for any brands BUT for lesser/cheaper brands there may be contaminants inside the can. Contaminants like air, water vapour, rust may be present in other brands. I'm talking about quality control (QC) of refrigerants. Other brands may use recycled refrigerants from other equipments/cars. You're safe with DuPont. Be sure you inspect its genuine hologram sticker if possible OR buy from a reputable seller. In practice DuPont will make your AC 10F to 15F colder than other brands. Important if you live in tropical climate. SUVA, KLEA and Ineos are OEM brands. You may use other brands but your results may vary.


Q3: Better to use refrigerant with premixed dye like the R134a with leak detector. Less one issue of how much to mix when using separate dye with syringe injector. Anyhow BOTH are applicable in your case. Same end result here.


Q4: Yes.


Hope these helps,
Amarin.