A Mityvac failure

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Touring5

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I was using my mityvac to do an oil change on the generator today and after extracting most of the oil I pumped the handle only to have oil begin sputtering out of the shaft at the T-handle.

Has anyone seen this happen? The canister was less than half full at the time. Seems like some valve or seal is sticking.
 
Which Mityvac model is it? Does it have an internal pump? If so, and if you don't drain the oil out of it immediately after each extraction, the seals will fail and the result will be as you described. I have now killed both a Mityvac and a Pella this way.
frown.gif


Let's see how many more I kill before I learn my lesson. My next extractor will definitely have an external pump.
 
It's a model 7400 from 2004-2005. We're experiencing a heatwave with 48 deg F temps (about 60 deg warmer than a week ago).

I often use it for lawnmowers and typically store it with oil in it - that may be the culprit. Would this indicate that it's "terminal"?
 
Happened to me as well with my 7400. Call up Mityvac... when mine started puking oil out of the vent, I called them and they sent me a replacement one free of charge.

I always stored mine "dry" as well, so AFAIK leaving oil in it has no impact on its life.
 
Originally Posted By: Touring5
Would this indicate that it's "terminal"?

Mine was the 7400 also. When I contacted the manufacturer, they stated that the internal seals are irreplaceable and hence the unit is dead. I haven't even tried to take it apart. Maybe I should have.

On the other hand, when the same thing happened to my Pela 14K, I contacted them and they sent me instructions on how to take it apart and clean it, which I did. However, I haven't used it yet since I cleaned it, so I don't know if I was actually successful with the cleaning. Besides, you will never be able to get 100% of the oil that got past the seals. A little bit will always spew out of the handle.
 
My 10 years old 2004 Mityvac 7201 with external pump is working good, I used it last week to change oil in my LS400 without any problem. It had been used for more than 40-50 times over the 10 years to change oil, ATF and bleeding brake for several cars.

My BIL used to borrow it for several years then he bought one himself 5-6 years ago, his is working well too.

The capacity is 8.5 liters, good to do oil change in a Mercedes engine because of the sump capacity of 8-8.5 quarts.

Mityvac 7400 is about $10-15 less than 7201 with slightly less capacity, and no dispenser function which is useful to transfer old fluid to recycle container(s) without spilling.
 
You may have hooked it up wrong. When you take the lid off there should be no hose on the underside of the lid... on the pump side. Otherwise you'll be drawing oil into the pump.
 
Originally Posted By: Warstud
You may have hooked it up wrong.

There is only one way to hook up a 7400. It's a sealed unit so there is no "lid" to take off.
 
Thanks for the replies. I think I'll contact Mityvac - can't hurt.

I bought the unit originally for changing oil on the 5-series, but have found it to be great for small engines. I don't relish the idea of having to buy another, but if it comes to that I'll have to consider the external pump version.
 
I would think that unless the design is such that liquid can never enter the vacuum pump, you would always have the possibility of it breaking. I bought a 12V electric pump which was designed to extract motor oil. Trying to take the brake fluid out pretty much caused it to give up.
 
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