AC VOV???

[Big T]

Trying to clear things up regarding the recommendation to install a VOV for the AC system on my '99 Burb.

It was recommended here on these Boards to buy the severe climate VOV here:

http://aapak.com/Qstore/p000047.htm

I placed an order for one at that site and got a message that they do not have a secure certificate. I proceeded with the order anyways, but I did not get any sort of confirmation of my order, shipping, etc. Don't know if I'll ever get it.

I then went to order a dryer/accumulator on Rockauto. While there, I was checking their orifices and they offer many. The confusing arises with their descriptions: Here is the normal climate 105- VOV by AC Delco:

http://www.rockauto.com/catalog/moreinfo.php?pk=668606

The description: "TUBE,A/C REFRIG ORIFICE 4 WHEEL DRIVE; FRT UNIT, EXC RR AC, OPTIONAL AUTOMATIC ADJUSTING ORIFICE TUBE FOR NORMAL CLIMATES (105 DEG-)"

I have 4wd, but I also rear AC. Sounds like this one will not work?

Four Seasons offers a servere climate VOV (105 DEG+):

http://www.rockauto.com/catalog/moreinfo.php?pk=869808

The description says "Front Unit; w/o Rear AC; Optional Automatic Adjusting Orifice Tube for severe climates (105¦+)". So again the question is will this work in my '99 Burb with rear AC?

While I'm on this subject of refurbing my AC, what other items will I need to purchase? I have a set of Robinair gauges on order. Have not bought a vac pump. Do I need a leak tester? Do I need any seal kits?

 

[bobbiemartin]

I live in hot and humid Florida and have had a Sub for 15 years. I have used the VOV in our (twin air) Suburban. I really didn't notice much difference. I just redid most everything in the AC system and went with a stock orifice tube. What you need are all the components working properly and the correct amount of refrigerant. If anything is marginal, you cannot cool the large interior of a Suburban. That means a free flowing condenser, good fan, clean evaporator, etc. Also make sure the blend door motors are working. If all the other components are working as they should and you have a proper charge of refrigerant the stock orifice tube will work fine. The VOV is not a cure for marginal components.

 

[THEFERMANATOR]

I put one in and it made the air warmer. It got swapped out right quick for a stock replacement white GM orifice. Mine will make ice on some of th hottest of days. Just got back from JERSEY and seen temps that were almost 100 and I was comfortable meanwhile the wife was huddled under a blanket for most of the trip. Only problem I have is my rear air actually freezes up because I need the updated rear expansion valve.

 

[Acesneights1]

It must be a West Coast thing, I had never heard of it until Warwagon mentioded it but I do mostly HE and Heavy Trucks so don't see alot of that.

 

[Big T]

We don't have the humidity of the East Coast. Just dry heat, but the inland areas can be awfully hot.

 

[bobbiemartin]

We don't have the humidity of the East Coast. Just dry heat, but the inland areas can be awfully hot.

I grew up in Orange County. Yes it can get hot there, but you don't know what heat is until you experience Florida in the summertime. 95-100 degrees at almost 100% humidity must be experienced to understand it. And its still hot at midnight!

 

[Acesneights1]

You guys can keep it too...I'm moving to Maine when I retire.

 

[Big T]

I grew up in Orange County. Yes it can get hot there, but you don't know what heat is until you experience Florida in the summertime. 95-100 degrees at almost 100% humidity must be experienced to understand it. And its still hot at midnight!

Yep, even when it gets in the 100s we cool off at night with a cool ocean breeze. I've grown up in the OC and the weather is why I've never left. Been in Florida, though not in the dead of summer. I can only imagine. The only place comparable would be Loreto or Santa Rosalia in Baja. Like a humid blast furnace during July/August. Florida has great fishing, but I just don't see myself living there.

 

[THEFERMANATOR]

I don't know about FLORIDA being the worst. I just got back from Jersey and was happy as could be to get back to Fl as I couldn't take the weather up there any longer.

 

[mitchedo]

I put one in my truck last year when I installed my new condenser. It works gangbusters at slow speed and at idle, but it doesn't cool the truck on the freeway. I got it at Autozone for about $15.

I'll be swapping it out for a fixed OT.

 

[Burning oil]

On mine I did use the VOV. I bought the truck recently and a/c was not working. Short story is on my truck I think the VOV was a great improvment over any other 92-2000 truck I have ever driven. It is very cold. I can not compair on this truck before and after though. I will say I will definately be using VOV on future a/c jobs because of the cooling performance on this truck. The price is only $15-20.
Installed a new comp, cond, dryer and flushed system.

 

[Missy Good Wench]

If the factory parts are in good order there should not be any issues.

If the system is down, replace the accumulator (large can near the firewall)

Be sure the condenser is free of bugs and crap so the air can flow.

A sniiffer is a great addition to the tool box.

The VOV is supposed to allow more refrigerant to flow at low engine speeds and give colder air while the car is running slow in traffic.

Never had any real luck with the things.

The factory parts seem to work about the best.

If your unit is not producing cold air then there is an issue with things.
Improper charge.
Plugged condenser (bugs or dirt)
Bad compressor
Moisture in the system causing internal iceing of the orifice tube.
Excess amount of oil charge.
Factory orifice tube filter screen is plugged with crap (usually from a compressor that is eating itself)

If you find any metal junk in the screen. Flush the system completely, replace the accumulator and the orifice tube and replace the compressor.

Recharge to factory specs with fresh oil and Refrigerant.

Keep us posted

Missy

 

[WarWagon]

Never used VOV with rear air. However in my 95 Yukon out here it makes a difference at idle. We have 110 degrees and high humidity in AZ with the monsoon season. Humid conditions pull more moisture out of the air and less temp difference. The factory setup on the 95 Yukon and several other new 2006-2007 Trailblazers can't cope with 105+ outside temps. I also strapped a electric fan wired to the compressor clutch to the condenser as the clutch fan take too long to kick in. Radiator and cold engine keeps the clutch from kicking in and 160 - 180 degrees is the upper condenser temp range anyway.