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vacuum pump

Posted: Mon Jul 10, 2017 5:58 pm
by dolphins1131
i will be servicing my ac soon and already ordered me gauges and vacuum pump

its a cheap pair and was wondering if it will do the job correctly

heres the specs on the pump

5Pa
Oil Capacity
320mL
Voltage
110v/60hz
Inlet Port
1/4" Flare
Power
1/4HP
Free Air Displacement
3.5 CFM

i just thought of this could i just rent these tools from autozone or will these work because i was watching a youtube video and the guy had a cheap pump and it looked like he only got his vacuum 20 under the 0

Re: vacuum pump

Posted: Mon Jul 10, 2017 10:07 pm
by Cusser
I was 100 miles away from my vacuum pump, used the Autozone loaner, worked fine.

Re: vacuum pump

Posted: Tue Jul 11, 2017 12:38 pm
by dolphins1131
just picked up the vacuum pump loaner
is a 1.5cfm 1/6 hp but its a mastercool

Re: vacuum pump

Posted: Tue Jul 11, 2017 3:55 pm
by Cusser
Remember too that higher altitudes mean less numerical vacuum can be pulled.

Re: vacuum pump

Posted: Tue Jul 11, 2017 4:26 pm
by dolphins1131
that might be what it was
on the loaner gauges the low side rests at 5psi
i think the needle is bent

i pulled a vacuum on the gauges and it got down to -25
i then closed the gauges and its holding at -25 for the last several hours

should work for what im doing

whats the limits on how long i can pull a vacuum on my 98 mustang 3.8l
how does the oil stay in the system when vacuumed

Re: vacuum pump

Posted: Tue Jul 11, 2017 11:43 pm
by Tim
20 minutes.

Re: vacuum pump

Posted: Wed Jul 12, 2017 8:02 am
by Cusser
dolphins1131 wrote:how does the oil stay in the system when vacuumed
The refrigeration oil (and dye) are not volatile at ambient temperatures even at the full vacuum.

Re: vacuum pump

Posted: Wed Jul 12, 2017 9:47 am
by dolphins1131
is 20 minutes the longest or shortest amount of time i can pull a vacuum?

Re: vacuum pump

Posted: Wed Jul 12, 2017 10:08 am
by Tim
Run it as long as you want. But normally these 12 hours runs are over kill.