Thursday, October 1, 2015

I might start selling tools!

I might just start selling tools!  For a while now all the work has been engine swaps and parts changing.  I don't mean to complain, it's just that I have invested in tools and training to repair and overhaul and that's just not the way it's done these days.  I did a head gasket on an old Massey Ferguson a couple of weeks ago, but that is the first engine I've seen inside of in months.  We just replace with new now.  BORING! 

A simple socket set, an impact wrench, and a few pry bars and I would have enough to swap engines.  I don't seem to have a need for all the micrometers, torque wrenches, and gauges now. I don't even get a chance to hammer on anything anymore!

Please!  Someone save me from this monotonous pit of parts swapping!

Tuesday, September 1, 2015

Kubota Misfire


Todays repair is a Kubota M9960 with the customer complaint of an engine noise.  The driver also complained of a lack of power.
Checked engine for low power and making noise.  Hooked up laptop and found no codes present.  Engine has slight misfire with no load.  Did injector cutout test and found #4 cylinder had no change when injector was disabled. 


In the shop, I removed the injectors and checked engine compression.  Compression was low but within specifications.  I sent the injectors to the pump shop to be tested.  Injector #4 was stuck and all the other injectors were below specifications.  I ordered replacement injectors. 


I installed the injectors and ran the tractor on the dynamometer.  The horsepower was low (hard to see in the photo because of my reflection but it reads 77 hp). 
 I checked for fuel restriction and found low flow to the strainer.  The I blew in tank with compressed air to push the restriction out.  Next, I checked fuel pressure and found the pressure would drop to 0 psi above 1500 rpm.  The photo shows the setup I used.  The vacuum gauge to check for restricted inlet, a clear hose to check for air, and a pressure transducer hooked to a graphing meter to read pressure.

  Checked power supply to lift pump and found good.  I used a current clamp to measure current to the lift pump.  With the meter set to read two channels, I can graph current and pressure at the same time.  This is helpful to quickly determine of I have a power of pressure problem, and I can record the results for later use. 
 Replaced lift pump.  Rechecked fuel pressure.  Pressure now normal.  Ran on dynamometer and found 83 hp (rated at 89).  The horsepower is still lower than normal because of the low compression.  This is as far as the customer wants to go on this one.  The cure for low compression is a replacement engine, and that is very expensive to gain six horsepower.


Wednesday, July 1, 2015

The 10,000 hour engine

What do you do?  I have a Kubota M108 here with a severe engine miss.  I have isolated the problem to cylinder number three.  I did a compression test and compression is at the low end of the specification, but not below the spec for acceptable use. 

Now the tricky part.  The tractor has 10,000 hours of operation on the original engine which is about the expected life of the engine.  I could just replace the bad injector and it would run.  I could put a set of injectors in it and it would run better.  To replace the injectors costs about $4500.  A new complete engine costs $8500. 

Installing one injector in an engine with this many hours is not a good plan. I have replaced injectors one at a time only to have another injector fail within a few days.  A whole set of injectors is expensive, more than half the cost of a new engine.  It is a lot of labor to get the injectors out.

So now the lines blur.  If I just repair the fault, it will be back.  If I replace all the injectors, it will cost more than half of a new engine and will most likely need more repairs very soon.  If I put in a new engine, the rest of the tractor is still worn out.

What would you do?

Wednesday, April 22, 2015

There goes my job!

We have been in a drought for several years now.  It has gone on so long that jobs are now being lost.  Farmers are not planting because there is no water.  Repairs are being put off or just patched until there is some relief. 

My phone has stopped ringing.  I did have some loyal steady customers who kept me busy, but at this point I can't even count on them.  There is just not enough work

Just a few years ago I would have had several air conditioner service calls per week during this time of year.  I had a customer decide to remove the windows from his cab so he wouldn't have to replace an air conditioner compressor and evaporator recently.  Gone are the days that if the air conditioner, radio, and suspended seat all didn't work, the tractor parked until they were all fixed.