Dismiss Notice

Welcome To CK5!

Registering is free and easy! Hope to see you on the forums soon.

Score a FREE t-shirt and membership sticker when you sign up for a Premium Membership and choose the recurring plan.

More A/C ????

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by crashfirepm53, Jul 16, 2004.

  1. crashfirepm53

    crashfirepm53 Registered Member

    Joined:
    Mar 14, 2004
    Posts:
    62
    Likes Received:
    0
    Location:
    florida
    A/C isn't cold enough. What causes it to get cold.Compressor is almost new (6 Months).Also what should the high/low pressure be on the dual air Burb? Mine is 250H / 55L.Plenty of volume but needs to be cooler.
     
  2. ugly_blazer

    ugly_blazer 1/2 ton status

    Joined:
    Apr 12, 2004
    Posts:
    1,214
    Likes Received:
    0
    A/C doesn't really get cold, it removes heat. It does so by the coil in front of your radiator. If the coil is dirty it can't efficiently dispose of the heat and it is returned to the system, thus reducing the cooling affect. The coil may not be the problem, but it never hurts to keep it as clean as possible. /forums/images/graemlins/thumb.gif
     
  3. rjfguitar

    rjfguitar 3/4 ton status GMOTM Winner

    Joined:
    Aug 28, 2002
    Posts:
    9,097
    Likes Received:
    144
    Location:
    california
    Dirty condensor could be a culprit, make sure the evap is also clean, enough freeon but not too much. Too much freeon will make it stay warmer. The biggest thing I would bet on would be airflow, the stock fan doesn't pull a lot of air, does it get nice and cold on the highway? When I went to dual electric fans it feels like my A/C dropped 10-15* in town driving.
     
  4. crashfirepm53

    crashfirepm53 Registered Member

    Joined:
    Mar 14, 2004
    Posts:
    62
    Likes Received:
    0
    Location:
    florida
    I cleaned the evap. and cond. but they were both clean.It does appear rather hot in the engine compartment or alot of hot air.Any good and easy Electric fan setups that are recommended as an replacement.I gotta do something.Running Both A/C's on high all the time cannot be good.
     
  5. crashfirepm53

    crashfirepm53 Registered Member

    Joined:
    Mar 14, 2004
    Posts:
    62
    Likes Received:
    0
    Location:
    florida
    Oh yeh it doesn't get any cooler on the highway.Honestly I think it is cooler at idle.
     
  6. rjfguitar

    rjfguitar 3/4 ton status GMOTM Winner

    Joined:
    Aug 28, 2002
    Posts:
    9,097
    Likes Received:
    144
    Location:
    california
    [ QUOTE ]
    Oh yeh it doesn't get any cooler on the highway.Honestly I think it is cooler at idle.

    [/ QUOTE ]
    Then electric fans will not help you. When the system was "redone" did the orifice tube and accumulator dryer get replaced? Was everything flushed out well? BTW...is it R134 or R12? I know on a single A/C system you should have 36 ounces of R134. Sounds like it is not flowing well through parts that didn't get replaced or you have too much or too little freeon.
     
  7. crashfirepm53

    crashfirepm53 Registered Member

    Joined:
    Mar 14, 2004
    Posts:
    62
    Likes Received:
    0
    Location:
    florida
    O-tube and dryer was replaced and 42 ounces of 134 was put in.I just got back today from a good A/C shop and he said that the older GM R-12 systems tend not to be that great with 134 as with theolder Fords.
    The system pressures were fine.The high pressure was 255 and when water was sprayed on the condensor it dropped to almost 200 as well as interior tekp dropped.He recommended replacing the 134 with R-12for $350.00 .It it didn't improve he'd switch it back no charge.Also said I could match up a newer R-134 system condensor and put on mine.The newer condensor are designed for 134 and are a dual flow design so it cools better.Also recommended the electric fan.Anyone know a condensor that matches up line connection and diameter?6 on top 8 on the bottom.Passenger side exit.
     
  8. Blue85

    Blue85 Troll Premium Member

    Joined:
    Jul 26, 2000
    Posts:
    9,084
    Likes Received:
    486
    Location:
    Grand Rapids area
    In Florida it's really hot. Even an A/C system in good shape may not blow super cold.

    Check to make sure the heater / A/C door is closing all the way with a good seal. You could also do a heater core bypass to eliminate all engine heat from under the dash.

    When converting to R-134, the total charge amount should be lower than it was for R-12. I think about 80%. Was the orifice tube changed? The stock GM one (white) works OK, but it's better to go with a smaller one like the standard Ford one, which is blue or green (I forget). I like the VOV better and have seen real improvement from it.

    Airflow is also very critical. You don't cool the interior any more than you cool the condensor. Check your shrouds around the fan and between the condensor and radiator. Make sure all of the air has to go through the condensor. Sometimes you have to add some plastic or sheet metal to block off "sneak paths". Also check your fan clutch and make sure it is holding OK.

    In Florida, running R-134 in an R-12 system, you should be running a high-pressure cut-out switch. Was the low side switch adjusted or replaced to match R-134 pressures?

    I would only look into a new condensor after all of the other stuff has been looked into. I have good performance from mine with an old compressor. I use the VOV, added extra shrouding and switched to dual electric fans. The worst I ever see is about 95 degrees, though.
     
  9. crashfirepm53

    crashfirepm53 Registered Member

    Joined:
    Mar 14, 2004
    Posts:
    62
    Likes Received:
    0
    Location:
    florida
    I know indiviguals have differnt exper. but I keep getting diff. opinions that are confusing.I've had a couple of pos. VOV responses from here but a few A/C guys tell me that they 've seen no improvement.A couple of pos. for the electric fans and then another that says the airflow won't help.I'm not sure where to go at tgis point.I guess the cheapest and then up.
     
  10. rjfguitar

    rjfguitar 3/4 ton status GMOTM Winner

    Joined:
    Aug 28, 2002
    Posts:
    9,097
    Likes Received:
    144
    Location:
    california
    [ QUOTE ]
    I know indiviguals have differnt exper. but I keep getting diff. opinions that are confusing.I've had a couple of pos. VOV responses from here but a few A/C guys tell me that they 've seen no improvement.A couple of pos. for the electric fans and then another that says the airflow won't help.I'm not sure where to go at tgis point.I guess the cheapest and then up.

    [/ QUOTE ]When I said electric fans wouldn't help I meant that if it doesn't get any colder on the highway than you are getting enough air flow or something else is the problem. It is true that R134 isn't as good as R12 in our systems but I have had good luck with R134, it has never been colder and that is with an R12 condensor, but the 4600 CFM coming through it with my fans helps a lot.
     
  11. Blue85

    Blue85 Troll Premium Member

    Joined:
    Jul 26, 2000
    Posts:
    9,084
    Likes Received:
    486
    Location:
    Grand Rapids area
    Make sure your charge is correct, too. Once your low side line leading back to the compressor is cold, you have "enough". Continuing to add for while will keep the high side pressure kind of constant with no cooling improvement. Putting in even more drives the high side pressure up even more and with it raises the low side temperature.

    If you charge it with the R-12 amount printed under the hood, then you are Overcharged.
     
  12. crashfirepm53

    crashfirepm53 Registered Member

    Joined:
    Mar 14, 2004
    Posts:
    62
    Likes Received:
    0
    Location:
    florida
    well the rear A/C is critical to cooling the burb.However this is no where good enough.I prob. am going to invest in a new condensor from AC source.They have up to 4 parrarel flow condensors that should make a huge difference in the cooling.They are a universal fit so I am still waiting on a reply about connecting the lines up together as in what do I need.The most Expensive one the sell is I think 30'' x 19''!!!! And it costs $130.00. If that won't cool the burb then nothing will.I have to see the largest size I can get in there.
     
  13. Pookster

    Pookster 1/2 ton status

    Joined:
    Nov 21, 2000
    Posts:
    3,195
    Likes Received:
    0
    Location:
    NYC, NY, USA
    Try insulating the lines- I noticed significant increase in air coldness- just by using those slip on pipe insulators- One section is ususally enough to cover all the hoses.

    If its hot enough outside to use AC, think about how hot is is under your hood- Dont waste the coldness of the AC under the hood! insulate it all! Just zip tie it in place.
     

Share This Page