a/c help needed.

[HTX86chevy]

the a/c works really good on the freeway, im assuming because there is major air flow to the condenser. it even works (not great, but ok) in stop and go traffic... It does not work however when I am parked. blows room temp. air.

I know some guys have went the E-Fan route but my truck is not overheating, in fact the engine temp stays @ about 180 constantly. so I dont want to bother with E-fans..... The a/c had to have worked great when these trucks where new back in the 70's & 80's so my question is:

how can i get the a/c system working like it was intended to even at slow speeds or while in park? any ideas? Im still running the r12 system and don't want to convert.

1986 swb 5.7, 700r, 4barrel q-jet, engine is bone stock .

[Malo83]

Has the system been checked out for oil and R12 levels, my 83 had similar problems and was checked out and the R12 was low, once everything was bought up to specs she works great

[CaliDude76]

Originally Posted by Malo83

Has the system been checked out for oil and R12 levels, my 83 had similar problems and was checked out and the R12 was low, once everything was bought up to specs she works great

x2 on mine as well. actually tho, I had mine evacuted and replenished with 134a, and changed nothing else. I get vent temps on the highway around 45-50.. depending on the heat index outside.. at idle/stop go traffic, she'll get up to 60's (+-) That's about what you'll get out these units. It's kind of beneficial if you switch to the 134a, unless you know someone that still has r-12.. cuz its expensive.

with 134a you can get those home kits, and gauges that you can readily check the pressure of the freon. I juice mine up every summer, because it does lose a little bit, through the year.

and believe me.. this Central Valley heat, is no joke!

I'm sure Malo83 feels me on that.. I use to live in Visalia, then Fresno

[TheApocalyptican]

You could also consider putting an e-fan on just the a/c condenser itself, and wire it up to run only when the clutch of the a/c is running.

Like the others said, have the charged checked. An undercharged system will have more effect at idle and stopped due to the system not getting as much air over the condenser.
Also, make sure the fan clutch works. A new fan clutch when "disengaged" still runs at something like 30%, so if it doesn't, you will lose air flow at idle or slow speeds.

[Edahall]

Are the condensers out of a Suburban with rear A/C larger? If so, you might consider installing one of these larger condensers.

[TheApocalyptican]

Originally Posted by Edahall

Are the condensers out of a Suburban with rear A/C larger? If so, you might consider installing one of these larger condensers.

I've seen people say that they are larger. However, all the parts numbers(at least on the internet) seem to interchange, which suggests that no they are not.
Didn't even think about it before, but if you are willing to swap out the condenser, there is a more efficient parallel flow model that is a direct fit for our trucks.

[HTX86chevy]

do you have any info on the condenser that you mentioned?
I had the freon level checked today and they said it was good, that they dont see anything wrong with the system. How ever, they did suggest that i should try a shorter belt because mine seemed to be a little "loose". I will try a new smaller size belt and see what happens.....

[TheApocalyptican]

Go here. It's part number 7-3642 from spectra. The site I linked doesn't have much info on it, but after finding the info on other sites, they are the cheapest due to the free shipping over $75. Even their own ebay page sells it for slightly more.

[87chevy.com]

I would see if the fan clutch is bad first. with the engine off, try and spin the fan blade.. if it spins freely its worn out... its not supposed to spin freely. 2nd get the a/c system check out by a professional unless you have all of the equipment. it sounds like you dont have the equipment via the questions your asking. what the pro should do is evacuate the system see how much oil is recovered, add the same amount or even a tad more. compare the recovered refrigerant to spec, and refill. if it was low, you got a leak, if it was at spec, your not pulling enough air off of the condenser. also when they check the a/c pressures they can see if your compressors working properly. if you dont have the tools your gonna spend money and probally be wasting it.
clint

[TheApocalyptican]

forgot to add in my last post about the condenser that I have one on order that should be being delivered to me on Monday. So if you wanna go that route, I'd say wait and let me make absolutely sure that it will fit like it's supposed to before you go and spend any money on it.

[Edahall]

Originally Posted by TheApocalyptican

forgot to add in my last post about the condenser that I have one on order that should be being delivered to me on Monday. So if you wanna go that route, I'd say wait and let me make absolutely sure that it will fit like it's supposed to before you go and spend any money on it.

Is this condenser more efficient than the OE condenser that's in my 1990 Suburban? When did GM go to parallel flow? The A/C blows pretty cold but I wouldn't mind for it to blow even colder. I can always use more cooling considering the amount of space that's in a Suburban to cool and the hot and humid weather we have down here in Texas.

Also, how do you remove the old condenser? It looks like the radiator has to be removed to accomplish the task.

[TheApocalyptican]

Originally Posted by Edahall

Is this condenser more efficient than the OE condenser that's in my 1990 Suburban? When did GM go to parallel flow? The A/C blows pretty cold but I wouldn't mind for it to blow even colder. I can always use more cooling considering the amount of space that's in a Suburban to cool and the hot and humid weather we have down here in Texas.

Also, how do you remove the old condenser? It looks like the radiator has to be removed to accomplish the task.

GM didn't actually go to parallel flow til at least 94-95 when they went to r134a. The condenser I ordered is an aftermarket that was pretty much made with the idea of people with our year trucks switching to r134a. But, there's no reason you can't use the condenser with r12.

As far as removing the condenser....on mine I was able to do it by just removing the brackets on top of the radiator, and tilting the radiator back.

[blackbeaSSt]

not trying to hijack htx's thread but i am having ac problems as well. 1 problem im having is of course cooling. my mechanic charged it and loaded it with freon and its still nothing to write home about. i think he said something about a bag or something or other not being blown up to full spec? i dunno stuff like this is over my head!

problem #2 is my truck runs fine while driving with the ac on. BUT, when i have the air on and im stopped at a light or stop sign it pretty much dies on me. so i either cut it off while stopped or torque brake it to keep it running.

would setting the idle higher help the killing while stopped? im up for all ideas!

[Goldfinger]

Black there is a such thing on our vehicles for running a/c while stopped it's called an idle compensator it raises the idle allowing the engine to run properly. I had low air pressure through my vents. i crawled under the dash to find 25 years had harmed my vents with some duct tape around the seals it remedied the problem. For max cooling i added insulation around my lines to prevent thermal loss. Also my a/c has an adapter to allow use of 134 with the existing oil and r12. also check for leaks.

[blackbeaSSt]

Originally Posted by Goldfinger

Black there is a such thing on our vehicles for running a/c while stopped it's called an idle compensator it raises the idle allowing the engine to run properly. I had low air pressure through my vents. i crawled under the dash to find 25 years had harmed my vents with some duct tape around the seals it remedied the problem. For max cooling i added insulation around my lines to prevent thermal loss. Also my a/c has an adapter to allow use of 134 with the existing oil and r12. also check for leaks.

thanks gold. worse case i'll take it to an auto air specialist. my guy mainly stops at adding freon. and i do think im running 134

[HTX86chevy]

The apocalyptican : please give an update when you get that condenser. I am very interested to see if it makes a difference in cooling.

Blackbeast: no worries buddy, lets get these a/c's fixed cuz this heat is ridiculous!

87chevy.com: so , i went outside to test the clutch fan per your instructions and she spins freely by hand with the engine off! I removed my belts, and I'll be replacing them in the A.M. , should I swap out the clutch fan? any recommendations/experiences with any brands? also how would i remove it?

looking at the autoparts websites they state that there are different fan clutchs depending on gear ratio. how could i determine what i have.
Thanks guys for all the helpful tips/info!

[Edahall]

Originally Posted by HTX86chevy

any recommendations/experiences with any brands? also how would i remove it?

looking at the autoparts websites they state that there are different fan clutchs depending on gear ratio. how could i determine what i have.
Thanks guys for all the helpful tips/info!

Try to find a clutch fan that comes with a lifetime warranty. They commonly go out and if you plan on keeping your truck for a long time like myself, very likely it'll go out again in the near future.

[ujsf01]

87chevy.com is right! If you're not careful, you can spend a pile of money throwing parts at it and still not resolve the issue. One of the major keys in properly diagnosing an a/c problem is know what the high and low side pressures are with the system operating at idle and at 1500 rpm. Head pressures can tell you a lot of information about what is going on inside the system. If you have a set of gauges and can get those readings, maybe I can help.

[78 Chevyrado]

If you want to find out if low airflow is the problem, put a BIG fan in front of the grille and sit there in drive and see if it gets cooler or not.

Might be a good idea to pull out the grille and put some coil cleaner on the condenser and pick out all the bugs and stuff and straighten out any bent fins you find. Would also be a good idea to pull the top of the radiator loose and tip it back to see what the front of that looks like too. put coil cleaner in both of em.

If it does get cooler with the fan blowing on the truck, It's an airflow problem and you could buy one of those little cheapie pusher fans and wire it to only come on when the compressor is running.

[notyo_cheez]

Originally Posted by HTX86chevy

The apocalyptican : please give an update when you get that condenser. I am very interested to see if it makes a difference in cooling.

Blackbeast: no worries buddy, lets get these a/c's fixed cuz this heat is ridiculous!

87chevy.com: so , i went outside to test the clutch fan per your instructions and she spins freely by hand with the engine off! I removed my belts, and I'll be replacing them in the A.M. , should I swap out the clutch fan? any recommendations/experiences with any brands? also how would i remove it?

looking at the autoparts websites they state that there are different fan clutchs depending on gear ratio. how could i determine what i have.
Thanks guys for all the helpful tips/info!

If the fan spins freely the clutch is fine, it's mounted on the studs for the water pump pulley. Defective fan clutch and it won't spin at all, and you'll know it when your engine sounds like a old B-52 taking off. You'll have to pull the fan shroud to remove it, I'd suggest leaving it alone since it works.

You can opt for a flex fan to replace it when the fan clutch does fail (and it will) and never worry about it again.

As for the a/c issue, if your freon pressures are okay I'd hook up a pusher fan, the extra airflow can't hurt.

[87chevy.com]

theres 2 kinds of fan clutch failures... kind when they leak and the fan blade spins like its on bearings, or when you turn the engine off and the blade keeps spinning.. the fluid inside leaked out. 2nd kind of failure is when the clutch siezes and then sounds like a b-52 taking off.
the big fan infront of the condensor was a pretty good idea.. you gonna need gauges to diagnose your problem

[TheApocalyptican]

My fan clutch seemed like it worked. It didn't have any oil leaking, and didn't spin like it was on bearings, but it never seemed to really kick on much. I changed the clutch and now it seems to kick on more. Basically mine was just barely working correctly, but didn't show any for sure signs of being on it's last legs.

As far as the condenser, I had a universal parallel flow in the suburban, but didn't like the way it fit, so I switched it to a piccolo style(which is what I am currently using) and the parallel flow definitely made a difference. Big thing tho is that I am running r134a so I can't say how much cooler the parallel flow would actually make it with r12. Would be better for sure, but just can't say how much.

[HTX86chevy]

When I first crank up the truck my fan is running. I never see the fan stop . is this a prob? I switch the v belt and it did seem to make a difference, but i wont know for sure til i test drive her.

I did try the card board test w/ the fan (looked it up on youtube) and the fan ate up my card board . lucky i didnt use my hand!

I have to try that cleaner that someone mentioned above because i took a good look at the condenser and it seems to be super clogged with grime and bugs. i'll clean this thing out and see what happens. might even try the pusher fan that you guys mentioned.

[TheApocalyptican]

Originally Posted by HTX86chevy

When I first crank up the truck my fan is running. I never see the fan stop . is this a prob? I switch the v belt and it did seem to make a difference, but i wont know for sure til i test drive her.

I did try the card board test w/ the fan (looked it up on youtube) and the fan ate up my card board . lucky i didnt use my hand!

I have to try that cleaner that someone mentioned above because i took a good look at the condenser and it seems to be super clogged with grime and bugs. i'll clean this thing out and see what happens. might even try the pusher fan that you guys mentioned.

The fan should never stop completely. When they are disengaged they should still spin at like 30%, which makes it not sound like a jet engine, but still cools some.

If the condenser is dirty/clogged up at all, get it clean before trying anything else or spending money on anything.

[TheApocalyptican]

Wanted to post in about the condenser. Tonight I got down to 38°F at idle in my driveway. I basically have a new compressor, new parallel flow condenser, 1 year old hoses, and a 4 year old evap. It took quite a bit of playing around with the charge to get to this point, and right now I am not really sure how much charge I actually have, but I'm guessing around 28-30 oz.

Is there a source for the seal/gasket that is attached to the small duct portion that removes for access to the blend door? I am currently losing air due to the seal not being good enough.