Navara d40 A/C manifold gauge readings

[Navarato]

Hello everyone

My A/C was a little bit getting warm at idle so I tried to add some Freon till I got this reading:

is this normal reading on a/c full blast fan speed :4 and ambient temp is 27c
ac is cold at idle for for half an hour no problem and clutched is engaged all the time

but when I lower fan speed to 2 clutch start to dis/engaged more frequently and low side pressure keeps fluctuating between -30 to 40 psi with clutch dis/engaged

I feel like I did something wrong or missed something because frequent clutch dis/engagement is annoying

any help is appreciated

 

[Old.Tony]

It sounds like it's doing things right. At the lower fan speeds, the evaporator inside isn't going to absorb heat as quickly (lower thermal transfer rate) so the compressor won't need to come on as often. Mine does it too.

Yours is a left-hand drive? We don't use freon in Australia, we use some numbered thing like R134A or something like that.

 

[Navarato]

Thanks Old.Tony
mine is r134a too, I wrote Freon maybe because I'm used to it

 

[Navarato]

is 250 psi too high?

 

[Old.Tony]

I'm not an air conditioning mechanic so I've never measured it. The manual doesn't say what it's supposed to be either. I do know the pressure gets pretty high, we had a fan belt start to let go and it whipped through the flexible section of the refrigerant line and released it while we were driving. It certainly made some noise and the gas left in a big hurry, so it must have been under considerable pressure.

 

[BarneyB]

I don't know the exact design specs for the Nav's A/C...
But those numbers don't look bad for 134A. You wouldn't want it much higher on the hot side.
As for the clutch behaviour, it's quite normal for the system to engage & disengage regularly on partial load.
My wife's Honda short cycles the comp all the time.....it drives me bonkers, but the dealer tech reckons it's normal.

Don't keep adding refrigerant if you're unsure - an overcharged system brings new flavours of headache.