The “Money Pit,” Do you Own One?Tuesday, September 1, 2009
When a scrubber breaks down it is pretty straightforward by most technicians. They either:
- Are familiar with the problem or symptom and know how to fix it right off or
- Not familiar with the symptoms and may read the service manual first. They may also contact the manufacturer for advice on how to handle the particular problem. What you don’t like to see or be involved with is:
- Know the symptom, however, there are multiple answers to the solution. This is what I refer to as the “Money Pit” (in reference to the movie staring Tom Hanks).
However what I am about to tell you is an absolute truth. There was a Tennant Scrubber Model 510E. Let’s start with a little history about this machine. This machine was produced between 1990 and about 1996. The Model 515 replaced it around 1997. It is a scrubber with an optional pre-sweep. It is 36-volt battery rider. I would consider this machine to be a mid-size scrubber. It scrubs with either two rotaries or an optional three rotary system. So, let’s continue with the story.
I was contacted in mid-stream of the problem and did not know that fact. My customer contacted me stating that the brushes and rear squeegees will not lower to the floor or when they do they will not stay down and came right back up. The customer asked if I could advise him on what to do. Not to identify him, I’ll call him “Tom.” So, I told Tom that I was very familiar with the Tennant 510E and, by the way, “your number came up today so I can help you today.”
Seriously, there are several items I would list for him to look at:
- Low battery or a bad battery. First I would put a full charge on the battery. This machine usually was fitted with one large 36-volt battery. I have seen where it could be individual cells in the battery. If the full charge does not work get the battery checked by an expert.
- Check the actuator motor and actuating screw. Look for frayed wires to the motor tracing them back to the circuit break and relay.
- Check the bristle length of your rotary brushes. Oh, yes! If the Bristles are too short the machine has a sensor to raise them back Up. You’re looking for not less than ½ inch to replace them. Either way, replace them anyway if they are less than ½ inch.
- Check the scrub brush switch and actuating switch on your deck.
I recommended that he start here and let me know. The next day he writes:
I have already replaced the battery with a new one. The scrub brushes were replaced also. I already bought and installed a new actuator for the scrub deck. I was told it might be the scrub brush motors so I installed new on both of them. I now have about $6,000 stuck in this old machine my boss is starting to get aggravated. Can you help?
I answered that I would try and go back to my service manuals and old notes. You see I have rebuilt quite a few of these old 510’s and I always keep my notes. For example, the symptoms, problems and solutions.
After referring to my past notes there was one machine that acted in a similar fashion. The machine was used in a large cooler and condensation would form all over the machine. Going in and out of coolers can cause havoc on an electric scrubber.
What we discovered was condensation was building up inside of the contactor relay and the contacts got rusty. So, it would not make contact on a consistent basis. Also, I would recommend replacing the two 40 amp circuit breakers.
As you remember Tom Hanks had “weak” trees in his yard and they, well, they just fell over! What my customer had was weak circuit breakers and weak relays. I was sure this would solve the problem and I had these parts in stock. If this doesn’t solve it we were at least on the right track. He ordered the parts and I sent them to him.
About a week later Tom e-mailed me with a simple note. It said:
I had weak relays!
Thanks for reading every month. If you own or know someone who has a “Money Pit” e-mail me and let me know their problem, firstname.lastname@example.org. Remember, I am not here for problems, only solutions!
P.S. The best part of the movie was where Tom Hanks and Shelley Long were pouring water in the bathtub right before it falls through the floor. He stands there just laughing…ha, ha, ha, ha, ha!