B2300 AC problem

[crazypj]

Hi all,
Been quite a while since I actually logged in
I've (still) got my 2004 B2300.
Last week I found the AC isn't working
Had a look at things today, the AC clutch is cycling on and off, even on max cooling.
Tried adding refrigerant but not sure I'm using the correct port?
I can only find 2, large diameter drivers side front (in front of battery) and small one on top of receiver/dryer on passenger side (at least I think that's what it is?)
Is there a third port to add 'gas'?
Pressure varies between 90psi when clutch cuts out and 35psi while running
It's got about 90,000 miles (don't use it much since I got laid off)
It isn't too hot in Florida at present so living with it isn't much of an issue, but, summertime will be a problem
Any help will be much appreciated
Thanks

PJ
BTW, I tried search but only found 2 posts, neither of which seemed to apply

 

[PanamaExpat]

Sounds a bit low on gas or possible debris in the expansion valve or other possible blockage. You have the correct ports. With the engine running and the air conditioning on, the low pressure side should read between 30 and 43 PSI. Here is a link to an automotive AC forum that has been very helpful to me. One big question...Do you have the correct stuff to work on it. Gauges, vacuum pump, freon recovery system, etc. Here I don't need the last one but I know in the USA they are real nasty about dumping freon into the atmosphere. Do keep us up on what you find I'll help with what little I know about car systems. I do a lot of residential and small commercial AC work but very little on cars.

http://acsource.net/acforum/index.php?sid=7acf1fcd552e644d7d8eeeb77edc058a

Can you also get us a high side reading? When the compressor is running does it make any odd sounds like it is slugging the valves?

 

[crazypj]

I can't get R134 to go into system?
There seems to be a solenoid or sensor on the tube?
I have fitted a set of 17" Mustang wheels though

 

[adsm08]

Buddy, I am not conivnced that you know enough about what you are talking about to be describing it correctly.

Get us pics.

 

[crazypj]

Yep, sounds about right, I only learn car stuff when I have to
Maybe pictures would help?
I'm a really experienced motorcycle mechanic though,(40+ yrs, almost 12 yrs teaching techs)
I don't usually work on stuff this crude (16~20,000rpm, inline 4, 150~200bhp/litre compared to 145bhp, 2.3litre)
I'm quite happy with low power motors though (less than 75bhp/litre)
It's a real simple system it's just the first time I've actually looked into AC
I was laid off 19months ago, have couple of herniated discs and pretty severe damage to left arm (all work related) I'm too broke to pay someone to do this stuff
If I had cash coming in things wouldn't be so dire

 

[adsm08]

So far so good. Your "fill port" is actually the low side service port. That is the low-side pressure sensor.

You probably can't get stuff to go in because the pressure in the can and the pressure in the system are too close. Start the truck up and kick the A/C on. It will help draw the stuff in.

The other option is to leave the truck sit in the shade and wrap the reefer can in a heating pad.

 

[crazypj]

Thanks, I'll try that. I thought it may be a pressure differential thing.
I'm guessing the sensor 'reads' low pressure in system so kicks out the clutch, when the pressure rises, kicks back in?

 

[crazypj]

Used a jumper on the low side sensor to keep compressor running. (just disconnected sensor and jumpered at wiring harness)
Got 2 small cans of gas in there, have some cold air now.
Still needs another can or two, as it's only showing 30psi(wouldn't keep running long enough with everything connected to get an accurate reading, was closer to 2psi than 35 )
I'm wondering where the leak is though, it had to go somewhere?
I guess after I track that down and fix it, I'll chop a couple of coils on front and flip hangers on rear, really needs a couple of inches drop
Question,
If I flip spring hangers then use longer shackles, won't it have effect of lowering another inch or so? (cheap way of doing a 2-3 rather than a 2-2)