I may have put too much stop leak in my A/C charge (R134a), or at least that's what I think the gauges are telling me. How would I go about cleaning it out?

 

Why do you think that you have too much, what are the readings.

To clean it out you would need to flush it out with flushing solvent that you can get in an aerosol can but you need to remove the compressor and physically dump out the oil, flush out the evaporator and the condenser with the solvent.

Replace the receiver/ drier and then when it is all back together you need to replace the appropriate type of oil into the system. 7.25 ounces

Stop leak is not a good fix; it can block the restrictor in the H-valve.
Where is it leaking?

I bought some flush at Auto Zone for about $15.00 2 weeks ago.

Jim

 

The pressure side looks fine, but it won't take any more on the suction side, just a lazy gauge reading that is low... I was hoping you would help me Jim!

 

How much did you put in? 80% of 44.0 ounces is 35.2 ounces or 2.933333333cans.

So are you saying that you cannot get any more into the system?

Be sure to have a good size fan in front of the radiator when you are charging the system.

Jim

 

My air would work great and be cold all day, then last stop of the day just stop working. I would check it and it would be out of charge. Never could find the leak. Part of the problem (I just found out) if my electric fan has been intermittent, and I think that might lead to excessive head pressure and leakage.
What do you think?

Just checked, bad fan relay. I have some 70AMP relays coming to replace my 30's...

 

Was it completely out of charge or was it just low?

If you loose the airflow through the condenser the head pressures could easly exceed 400 PSI and cause it to vent through the relief valve but you should not loose everything just until it reaches a safe level unless the relief is bad from it repeatedly opening.



Check the relief and see if there is any amount of oil around the end of it, when the refrigerant is released rapidly it will carry the oil out with it.

This particular fine design will discharge the oil onto the serpentine belt and could cause you to see smoke as it is being burned off.

What kind of electric fan do the have? I just checked on a Hayden Fan and the specs say that it draws 20-amps continuous which seem kind of high to me. I would defiantly install a 70-amp relay.

With an electric motor it is not the running current that kills contacts but the starting current when the motor is at a stall, it can easly pull 80-100 amps for an instant burning the relay contacts, also when you cut the power to a motor it will act as a generator and will be feeding current back into the relay contacts feeding the arc until the gap is wide enough to break it. Some will install a freewheeling diode across the motor leads to suppress the arc from the reverse EMF.

This is the relay that I would use to control a cooling fan, it is far more dependable for controlling inductive loads, inside this relay there are actually 2 sets of contacts, there is a Leading and a Main contact. Instead of trying to explain how it works you can download the Catalog in PDF.



Read the description on page 15.

http://www.boschmotorsandcontrols.co...ais/relais.pdf

Here is a comparison between a 75-amp unit and a regular 20/30-amp



Jim

 

Thanks Jim. I'll check that vent. It's hard to see down there because everything is covered in gunk! I am going to think about a diode to kill the standing wave coming back from the fan. I wonder if a capacitor (al-la points type distributor) and a diode....