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What's wrong with my vacuum pump?

Jack32 on Wed September 17, 2008 4:10 PM User is offline

I have a MasterCool 1.5cfm 2-stage vacumm pump that stopped working this past weekend. It is less than a year old and been used about 3 or 4 times.
I was in hte process of pulling a vacumm on my truck when I swithced it off for about 20 minutes to check for leaks. When I turned it back on, it started to shake violently. I immediately shut it off. When I hit the powere switch the pump does not spin up. It only makes a humming sound. The oil is new and at the correct level. I left the purge valve open for 2 minutes before trying to pull a deep vacuum. For the life of me I can't figure out why it will not start.
Maybe the thermal cutoff tripped and needs to be reset. Any thoughts?

thanks

mk378 on Wed September 17, 2008 4:26 PM User is offline

While it was off but connected to an evacuated system, it could have sucked oil back into the pumping chamber, leading to a hydro-lock condition. Always close the inlet valve while checking for leaks to prevent this. It might clear by itself eventually. Turn it upside down with the hose off and the valve open and see if oil comes out of the inlet.

Jack32 on Wed September 17, 2008 4:34 PM User is offline

Quote
Originally posted by: mk378
While it was off but connected to an evacuated system, it could have sucked oil back into the pumping chamber, leading to a hydro-lock condition. Always close the inlet valve while checking for leaks to prevent this. It might clear by itself eventually. Turn it upside down with the hose off and the valve open and see if oil comes out of the inlet.

Is there any way to open the front cover and clean things out or am I screwed?

mk378 on Wed September 17, 2008 5:03 PM User is offline

If that's what happened, find some way to turn the motor by hand (be sure to rotate the same way it normally turns) and with slow moderate pressure you should be able to clear the oil out. First get as much out of the inlet as you can.

Gerald K4NHN on Wed September 17, 2008 11:22 PM User is offlineView users profile

Does that motor have a start capacitor. If it opened up the motor will just hum and not turn and get hot.

Gerald K4NHN
Cayce, SC

Jack32 on Thu September 18, 2008 8:48 AM User is offline

Quote
Originally posted by: Gerald K4NHN
Does that motor have a start capacitor. If it opened up the motor will just hum and not turn and get hot.



Gerald K4NHN

Cayce, SC


Yes, it has two start capacitors. What is the fix if this is the problem?

Jack32 on Thu September 18, 2008 9:06 AM User is offline

Quote
Originally posted by: mk378
If that's what happened, find some way to turn the motor by hand (be sure to rotate the same way it normally turns) and with slow moderate pressure you should be able to clear the oil out. First get as much out of the inlet as you can.

I turned the pump upside down but only a drop or two came out of the intake port. However, about an ounce did come out of the exhaust port. I drained all the oil out of the pump and it totaled about 9 oz. The total capacity is 10 oz. How would I turn the pump by hand?

TRB on Thu September 18, 2008 10:39 AM User is offlineView users profile

You might want to give Mastercool a call and explain to them what your issue is. While not the most courteous people (New Jersey) they can be helpful.

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Contact: ACKits.com

Gerald K4NHN on Thu September 18, 2008 8:57 PM User is offlineView users profile

Jack If it has two I would think one would be the start cap and the other a run cap. I wouldn't have thought it would have a run cap on that small of a motor. I usually get my AC start caps from the local AC supply house. Usually several $. But if it's under warranty, I'd let them supply the parts..

Gerald K4NHN
Cayce, SC

Jack32 on Fri September 19, 2008 9:44 AM User is offline

Quote
Originally posted by: Gerald K4NHN
Jack If it has two I would think one would be the start cap and the other a run cap. I wouldn't have thought it would have a run cap on that small of a motor. I usually get my AC start caps from the local AC supply house. Usually several $. But if it's under warranty, I'd let them supply the parts..



Gerald K4NHN

Cayce, SC

Jack32 on Fri September 19, 2008 9:48 AM User is offline

Quote
Originally posted by: Jack32
Quote
Originally posted by: Gerald K4NHN
Jack If it has two I would think one would be the start cap and the other a run cap. I wouldn't have thought it would have a run cap on that small of a motor. I usually get my AC start caps from the local AC supply house. Usually several $. But if it's under warranty, I'd let them supply the parts..







Gerald K4NHN



Cayce, SC





I would still have to pay shipping costs to send the pump in. Might be cheaper to buy them locally. Do you know of any places online that sell them? Our local AC shop is pretty anal about only dealing with licensed and certified contractors.

mk378 on Fri September 19, 2008 10:43 AM User is offline

New capacitor, or new pump?

Jack32 on Fri September 19, 2008 11:02 AM User is offline

Quote
Originally posted by: mk378
New capacitor, or new pump?

New capacitor

Gerald K4NHN on Fri September 19, 2008 1:03 PM User is offlineView users profile

I don't know the value of the caps, that will be marked on the side of them. Different motors take different values. Grainger Industrial Supply is in most large cities, you might try them. But if it's the motor or the pump, and it's under warranty, they 're going to tell you don't have any now that you've went inside...

Gerald K4NHN
Cayce, SC

mk378 on Fri September 19, 2008 1:52 PM User is offline

Allied Electronics has a fair amount of industrial stuff, or Mcmaster.

Disconnect the capacitor and confirm that it is bad with a VOM. Test for DC short, also charge it up with meter on ohms, then reverse the meter leads. It should show some resistance for a time until it charges the other way. If it shows infinity all the time, it is open. If it has a metal case, also check for short from the live terminals to the case.

Gerald K4NHN on Fri September 19, 2008 4:14 PM User is offlineView users profile

Some of VOM's have a range on them to check the value of the Caps also. It should be close to the marked value on the cap..

Gerald K4NHN
Cayce, SC

Jack32 on Wed October 08, 2008 3:18 PM User is offline

I sent the pump back to Mastercool and they said it is not under warranty. It is going to cost me $155 for them to fix it. Should I just trash it and buy a new pump or get it fixed. Mid you I only had this pump less than a year and I used it maybe 3 or 4 times. This seems like a manufacturing defect that should be covered under warranty. cheap piece of s**t

TRB on Wed October 08, 2008 5:37 PM User is offlineView users profile

That's odd as Mastercool warranty is for one year from date of purchase.

-------------------------

When considering your next auto A/C purchase, please consider the site that supports you: ACkits.com
Contact: ACKits.com

Jack32 on Thu October 09, 2008 9:37 AM User is offline

Yea it appears that Mastercool does not honor their warranty.

TRB on Thu October 09, 2008 10:34 AM User is offlineView users profile

Quote
Originally posted by: Jack32
Yea it appears that Mastercool does not honor their warranty.

Personally I have never been denied a claim on an item that was still under warranty. But we have had very few warranty items to begin with over the years.



-------------------------
When considering your next auto A/C purchase, please consider the site that supports you: ACkits.com
Contact: ACKits.com

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