A/C Upgrade Project starts tomorrow! - Page 3

mtbguy · 03-11-2008, 07:26 AM

Thanks Mark- I plan on putting in the DD condenser next week, followed by the barrier hoses, etc. It will probably be around mid-April before I'm ready to do any vacuuming.

I'll PM you around that time. (I'm in Tucker on the east side of town.) My goal is cold AC by end of April when it starts getting warm and humid again!

mtbguy · 03-11-2008, 07:28 AM

Quote:

Originally Posted by Barrpete

Yes, there is. Check to see if its marked on the expansion valve.

Thanks BarrPete- you saved me alot of grief......

mthomas58 · 03-11-2008, 07:42 AM

Now that the front condenser cage has been lowered, I'm going to order these skid plate spoiler protectors from our host # PEL-SP7002.

mtbguy · 03-11-2008, 08:15 AM

I was eyeing those as an addition to the Desert Duty condenser also- my factory hooks are already bent up/scratched a bit and are not that heavy duty. These look pretty beefy.

Mike Andrew · 03-11-2008, 08:51 AM

subbed

rusnak · 03-11-2008, 09:22 AM

I have those skidplates. They work very well. You might want to modify the mounting of the bumper bar to protect the front condensor.

Also, does anyone know if it is a bad idea to buy the 6 CFM 2 stage vacuum pump? I was looking at those prices, and I thought hey why not get the larger one and have excess capacity for bigger jobs.... Will it crush the tubing or pull too much vacuum?

mthomas58 · 03-11-2008, 10:00 AM

Pump and guage set arrived today - less than 24 hours from placing the order on-line INCREDIBLE! Co is based in NJ and the Robinair products were drop shipped from JAX.

www.thetoolwarehouse.net

scottb · 03-11-2008, 10:59 AM

Quote:

Originally Posted by rusnak

Also, does anyone know if it is a bad idea to buy the 6 CFM 2 stage vacuum pump? I was looking at those prices, and I thought hey why not get the larger one and have excess capacity for bigger jobs.... Will it crush the tubing or pull too much vacuum?

No, it won't harm your system.

FWIW, I recently scored a 6 cfm Yellow Jacket vacuum pump off of Craig's List for $50 (from a local pawn shop). It's a bit worn, but it works great. Can't beat it for the price.

If you're not in a hurry to buy a pump, keep an eye on CL and eBay.

My $.02.

Scott

tsuter · 03-11-2008, 01:41 PM

Quote:

Originally Posted by rusnak

IAlso, does anyone know if it is a bad idea to buy the 6 CFM 2 stage vacuum pump? I was looking at those prices, and I thought hey why not get the larger one and have excess capacity for bigger jobs.... Will it crush the tubing or pull too much vacuum?

Its not the CFMs so much, it's the Factory Micron rating you want. 20 microns or better!!! Robinair 15434 is excellent.

GH85Carrera · GH85Carrera's Garage

There really no such thing as too much vacuum. It is only the atmosphere trying to crush the hoses. That is nothing compared to the pressures the compressor will produce in the other direction.

The vacuum you can pull will be limited to the temperature and the altitude of your location. Wait for a 100 degree day and let the pump run for a long time.

mthomas58 · 03-13-2008, 05:28 AM

Quote:

Originally Posted by derkpitt

The best way to ck for leaks is to use pressure, not vacuum.
If it leaks some soapy water will find it.
Nitrogen gas would be my first choice.

Where would I find Nitrogen?

PS, thanks for the link on hose fittings. I actually have one of these that you're welcome to use if you ever need it.

derkpitt · derkpitt's Garage

Well Mark that's a good Q?
Don't really know where you would look on your side of town.

But I have a small bottle and set up to do just that job, I can load it to ya.

When your ready just give me a call and we'll set something up.

The nitrogen is dry and is great for purging and pressure testing the sys before servicing.

tsuter · 03-13-2008, 07:34 AM

Quote:

Originally Posted by derkpitt

Well Mark that's a good Q?
Don't really know where you would look on your side of town.

But I have a small bottle and set up to do just that job, I can load it to ya.

When your ready just give me a call and we'll set something up.

The nitrogen is dry and is great for purging and pressure testing the sys before servicing.

System pressure is 90psi-100psi but that not necessarily when it leaks. How do you plan to charge and pressure test with nitrogen at 240-300psi????? Are you going to run the A/C compressor on nitrogen?????

derkpitt · derkpitt's Garage

No. This is a static pressure test only.

The cheap N2 gas is only used to detect if leaks are present before servicing with the high dollar freon charge.
With the bottle pressure near 2000pis a regulator is used to decrease the pressure to only what is needed to assure the sys can hold a static pressure.
If the sys will hold pressure at 175-200pis then it will easily hold a vacuum.
Also the N2 is a inert gas without any moisture, which is good for purging air out of the sys with.

tsuter · 03-13-2008, 09:24 AM

Quote:

Originally Posted by derkpitt

No. This is a static pressure test only.

The cheap N2 gas is only used to detect if leaks are present before servicing with the high dollar freon charge.
With the bottle pressure near 2000pis a regulator is used to decrease the pressure to only what is needed to assure the sys can hold a static pressure.
If the sys will hold pressure at 175-200pis then it will easily hold a vacuum.
Also the N2 is a inert gas without any moisture, which is good for purging air out of the sys with.

I think I get the theory but can you be more specific on this for us DIY guys?

What kind of regulator? Source pics costs? How is it attached? Normal Mastercool gauge set??? What is the "Bottle of N2"? Cost sources.....

R134a only costs $5.50/can around here and if the syatem will hold a 20-30micron vacuum overnite, I'm trying to undestand what exactly it is that you are proposing that is better or cheaper for DIY guys.........

Maybe need a new thread.......

"How to leak check A/C with nitrogen for the home DIY???????????""

Kemo · 03-13-2008, 10:39 AM

subscribed.

Jim Sims · 03-13-2008, 11:33 AM

N2 refrigeration regulators, attachment hoses (with fittings to attach to R-12 type schraeder valves), and small (40 cu ft.) compressed nitrogen gas bottles are available new on E-bay. Sears also sells said regulators and hoses. Bottles may be obtained or filled at your local welding supplies vendor or compressed gas source. One has to obtain or fabricate adapters to attach to the R-134a systems. Nitrogen is used for pressure leak checking for two reasons: It is dry and therefore doesn't introduce water into the system. It is also inert and lacks oxygen as opposed to air which at the high test pressures required (~300 psi) can become explosive especially in the presence of fuel (refrigeration oil). Get training with compressed gases before working with this leak checking method. As always, wear full goggles or safety glasses with side shields.

Jim Sims · 03-13-2008, 01:05 PM

One point of clarification; in order to pressure test a typical automotive A/C system one shouldn't need to pressurize with N2 gas above 175 psi.

mthomas58 · 08:51 AM

Quote:

Originally Posted by mtbguy

Thanks Mark- I plan on putting in the DD condenser next week, followed by the barrier hoses, etc. It will probably be around mid-April before I'm ready to do any vacuuming.

I'll PM you around that time. (I'm in Tucker on the east side of town.) My goal is cold AC by end of April when it starts getting warm and humid again!

Sounds good. I hope to be ready to charge by this weekend - next at the latest (more honey dos - apparently the guest bathroom is in dire need of a new coat of paint!

) No worries.......this is how I earn time to work on the car.

I work near Lenox Mall BTW if its any easier to coordinate a pick-up during the week.

mthomas58 · 12:42 PM

An 8-10 hour job? Oh - I don't think so!

Weekend #2 - spent the day completing the Duehl Kuehl condenser installation, hoses, wiring and rock guards. Also cleaned up engine bay wiring from previously installed 3-fans on the rear deck condenser. Flushed the rear deck condenser with mineral spirits. It will be the only reused component in my new A/C system.

All thats left now is to install the rebuilt compressor, connect the high pressure lines at the ProCooler, evac and charge the system!

Here are a few pics from today:

Instuctions called for running the fan wiring through an existing rubber gromment in engine bay to the fender on "later year" cars or drilling a hole if no gromment is present. Since I could not find a grommet, I opted for running a wire along the high pressure line to the condensers rather than drilling.

Home brew condenser flush. I'm not real proud of this but it was effective. Flushed the rear condenser without removing it using a pressurized garden sprayer filled with mineral spirits followed by pressurized air to blow it all out. Got quite a bit of crud flushed out of it!