Windstar 2001 AC Low and High pressure reading

[pinjc]

Hello, I trying to fix my AC I have some data but experts recommend me replace all system...
here what I have: out side temperature 112 F, low and high pressure are equalized 108 psi both sides.
AC on for 5 minutes at iddle speed low is 62 psi and high pressure is 250 psi, running motor 2.5 k rpm
the low pressure is 47 psi and high pressure is: 290 psi. pipe line of low pressure is warm and cool air
inside car is 80 F. I read that low pressure should be lower that 30 psi. what should I check?
any advice ....thanks

 

[Chris142]

Suck it out and charge by weight. The old days or charging by pressures don't work the same as r12 did

 

[Powerglide]

It's overcharged or has air in th system. The air came from improper recharge technique.

 

[mclasser]

Originally Posted By: Chris142
Suck it out and charge by weight. The old days or charging by pressures don't work the same as r12 did

+1 A small DIY top off here-and-there is fine but your pressures seem pretty off. Time to take it to a shop for an evac & recharge.

 

[Chris142]

The lower pressures at speed vs idle tell me that the compressor is tired. After you get it properly charged we can start an actual diagnosis. My guess is that the compressor pieces are partially plugging up the condenser

 

[JHZR2]

Originally Posted By: Powerglide
It's overcharged or has air in th system. The air came from improper recharge technique.


+1

 

[pinjc]

thanks for the advice....

 

[ToadU]

Originally Posted By: Powerglide
It's overcharged or has air in th system. The air came from improper recharge technique.


This ^^^^. Also check condenser and clean w hose. Might be clogged with bugs. If it's 112 ambient outside and inside is 80 out of the vents that's a 32 degree spread.....40 degrees is what is optimum and realistic in a perfectly operating system.....your at 32 degrees.....with an older system with some wear....your not going to get much better. Even if the system was brand new and in perfect shape you would be hard pressed to get much better. A van has a huge area in cubic feet to cool inside too--if it's a dark color and no tint on the windows it's even harder. At most you will only get a few degrees cooler air out of the vents. You need to have realistic expectations. Just to be honest. People come into my shop all the time with similar spreads when it's uber hot outside. Most people want artic air blasting out of their AC vents but it's all about the spread between outside temps and what differential an AC system can lower it too--40 degrees max usually.

 

[KingCake]

Originally Posted By: Chris142
Suck it out and charge by weight. The old days or charging by pressures don't work the same as r12 did


This. Gotta charge by weight first thing. r134 systems are sensitive to +/- 2oz

 

[Lubener]

Originally Posted By: Chris142
Suck it out and charge by weight. The old days or charging by pressures don't work the same as r12 did


That would apply if R134 was a blend such as the freon used in residential a/c systems. Shops use gauges to recharge, they don't remove unless a purge is needed. In his case, the system is either overcharged or has air/moisture in system.

 

[punisher]

Something to remember also, you need to have a repeatable baseline for testing.

AC blower on high, recirc, 1500-2000 RPM, and a good strong fan to force air over the condenser. Verify your electric fans come on, likewise clutched fans need to engage. Vans with two evap cores (front/rear) need to have both ACs switched on. Vans with dual AC use differing orifice tubes front/rear, and incorrect ones throw pressures off. 40°F below ambient outlet temp is the minimum you should tolerate on a system. It is the failsafe to get us off the hook in case of marginal system performance. Real world, 50°F is the min delta I can accept, 55° if I am honest.

290 PSI high side is about the correct pressure for that ambient, maybe even a tad low. Conversely 47 PSI low side is a bit high. As others have said, moisture in the refrigerant can throw off pressures, usually high side pressures, but any sort of contamination can make a diagnosis tough. Systems don't contaminate themselves. A properly working system doesn't just become moisture contaminated. You have to have a "no pressure" situation, or someone has to charge with contaminated refrigerant.

 

[KingCake]

Originally Posted By: Lubener
Originally Posted By: Chris142
Suck it out and charge by weight. The old days or charging by pressures don't work the same as r12 did


That would apply if R134 was a blend such as the freon used in residential a/c systems. Shops use gauges to recharge, they don't remove unless a purge is needed. In his case, the system is either overcharged or has air/moisture in system.


You couldn't be more wrong. Today's r134 systems must be charged by weight. Blends? LOL. You're living in 1993

 

[Chris142]

Originally Posted By: Lubener
Originally Posted By: Chris142
Suck it out and charge by weight. The old days or charging by pressures don't work the same as r12 did


That would apply if R134 was a blend such as the freon used in residential a/c systems. Shops use gauges to recharge, they don't remove unless a purge is needed. In his case, the system is either overcharged or has air/moisture in system.
don't know what shop your dealing with.every good shop including me suck it out,vacuum and start fresh

 

[ToadU]

Originally Posted By: Chris142
Originally Posted By: Lubener
Originally Posted By: Chris142
Suck it out and charge by weight. The old days or charging by pressures don't work the same as r12 did


That would apply if R134 was a blend such as the freon used in residential a/c systems. Shops use gauges to recharge, they don't remove unless a purge is needed. In his case, the system is either overcharged or has air/moisture in system.
don't know what shop your dealing with.every good shop including me suck it out,vacuum and start fresh


+1

 

[zzyzzx]

Originally Posted By: pinjc
I read that low pressure should be lower that 30 psi.

It should be much higher than 30 PSI at 112 degrees F.

 

[irad]

Overcharged. With the engine off bleed the AC valve for two or three seconds. It should bring your pressures down. Remember when the ambient air is high the low side will be higher than 30, probably around 40 psi. If you do a vac and fill make sure a PAG oil charge is added. This will prolong the life of the compressor. I have a 2003 Windstar with 216K miles and perfect AC.