parts changers

Dad's been having some issues with the vacuum pump not maintaining enough suction lately, and so he had a service guy come out. He messed around with it for a little while, tore the pump apart and cleaned the vanes, blah blah blah... (and he took the liberty of rolling off the brand new drive belts Dad just installed shortly before without loosening the motor....)

Still didn't pull enough after that so Dad brought out the pump I rebuilt 2 1/2 years ago (I stamped on the end that it was rebuilt 3/30/2012) and the guy said it wouldn't work because it didn't have some seals on the ends like the other (much newer) pump did. So instead of putting that one on, he tore the pump apart AGAIN and still no better performance.

Today I went out there and Dad wanted me to look at it. I spent a couple hours putting on my pump I rebuilt but it still didn't change the performance much. But that's when I heard the vacuum leak from under the tank. Started it up again, got on my back and felt underneath the tank, and sure enough when I found and covered a hole with my hand the gauge shot up to 15-16 bar of suction. I put the weighted regulator back on (dip stick pulled that off and plugged the hole for that as well...) and as a temporary fix bought a tube of silicone caulk, cut up a plastic jug and patched over the hole. Once I did that, Dad had to adjust the regulator down because there was too much vacuum.

Dad hasn't gotten the bill yet from the other service guy, but he was there for 7 HOURS and there was no improvement in the performance. Gonna be a phone call when it does come....

Donovan from Wisconsin

Dog-gone-it. Wouldn't the first thing to do be to
put a gauge in front of the pump?

You would think a service guy would do something like that but I'm not sure he knew how to tie his shoes at this point.

I just did what dad wanted but I told him straight out I didn't think that was the issue and that he was just losing vacuum somewhere.

Turns out I was right...

Donovan from Wisconsin

When I used to moonlight fixing TV's (back in the day when you
could fix 'em, but that's OK I will take today's offerings in a
heartbeat) If I didn't fix it you didn't get billed. If I put a tube in and
it didn't help back out it came and you didn't get billed for that
either.

Mark

Yeah, that was then.... Today everyone wants to bill you for everything.

Just frustrating when I had a pump rebuilt and ready to go, and the guy instead wastes hours "rebuilding" because my old, but rebuilt pump, (that was on the vacuum tank for years before it needed to be replaced by the current one 10 years ago) looked different than the one currently in use.

What really got me is when he took the weighted valve off because "it wasn't doing anything".... IF he had found the actual problem, that valve sure does do something. When the vacuum gets too high, it lets the system relieve itself a little bit instead of sucking an already compromised ballast tank inside out because it can't help itself.

To rebuild he took the plate off one side, cleaned up the vanes and rotor, and schlepped it back together with RTV oozing out the sides. When I took mine apart it had no signs of RTV so it went back together with no RTV.

Seems to work just fine. Mom said they could hardly keep up last night because they were milking so much faster now. Last time this old pump was on they only had 3 units. Now they added a 4th bucket and a milk transfer unit so they don't have to sling buckets all the way to the cooler.

Donovan from Wisconsin

I am glad you got it going. Years ago when we used vane vacuum pumps. A few times when when they would not draw enough vacuum we had to do some work on them. The housing got a little out of round and scored up inside. I trued them up on a lathe. And, made up a grinder to get them smooth. The rotor had to be measured and offet a little to compensate for the material removed. Just something to keep in mind if you ever have trouble with your pumps. If I remember right you have the access and ability to do this.
Our pumps ran almost around the clock for years before we had this problem.
As far as parts changers, I have tried to stay away from them. When someone was called and had the result was like yours the payment was severly discounted.
ps I would not think rolling the belts would hurt them if they were new and pliable

The one I did I had torn apart for a few years and the bore got rusty, so I found a shop to hone it out. Only cost me $20 if I remember and 2 100 mile round trips. Local shops didn't have a hone big enough that I could find.

Turns out the new shop I'm at now can do it and they actually reman much larger pumps like that.

I took the end plates to the Blanchard grinder to clean up and remove the grooves worn in when the bearings went out on it. Works good now...

Donovan from Wisconsin

Well now wait a minute...

How can you blame a guy for not finding a simple and obvious problem that neither you nor your dad noticed either until much later?

I'm 100% sure you called the repair guy to "look at the vacuum pump because it's not pulling," not to check the whole system for a vacuum leak. You set him down the wrong road in the first place.

You were all pretty fixated on the pump being the problem. Maybe he would have looked elsewhere if you hadn't been hovering over him the entire time?

I say laugh, smack yourself in the forehead for missing something obvious, and pay the man for his time. At least, for the time he took to clean the vacuum pump because that was a legitimate service that it probably needed.

Dad called them to diagnose the system, not just "look at the vacuum pump" Unbeknownst to me they've been having vacuum issues for just about the whole summer. Otherwise I would have looked at it sooner. I help in the fields year round, but I may only milk 2-3 times in a year. Their farm, I'm the help.

When the guy came, Dad let him go about his business and his determination was that the pump wasn't pulling enough vacuum. While Dad was going about his chores he happened to look across the barn and see him rolling the belts off, and yes even with brand new belts you can break the cords and wreck the belts. Seen it before and had to replace brand new belts because the cords broke and they were running crooked.

I still maintain that he should have been able to find the real problem, not just throw parts at it. I changed the pump based on the guys determination that the pump was worn, and that his "rebuild" of it didn't change the performance. Once that didn't do anything, I looked a little deeper and found the problem.

Donovan from Wisconsin