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Letter 36

Isuzu Trek Members Infoletter #36

May 2015

Drive Train Vibration and Hydraulic Jack Fluid.  (Keith & Jody Redfern, kjredfern at

Hello Ken& Cathy, we are still enjoying our I Trek. I have had a driveline vibration problem with our ’92 28-footer that we cannot solve; we live with it. We have replaced the differential, had the drive shaft balanced & had all U-joints looked at, along with the center bearing. All fittings have been lubed religiously. When we travel at 50 mph plus & walk to the back of the coach, the very high frequency vibration comes through the floor. We have also had the rear tires off & balanced. No luck! We would like to know: is this the norm for a 28-footer? Another question is: has anybody changed the fluid in the hydraulic levelers? Ours has never had it done & I wondered  if anybody had any tips for doing it. Thanks for keeping the Infoletter going; we ought to have a National Isuzu Trek Rally before the vehicles become extinct along with the present owners.

Editor- We have a 24′ but I have been told Redlands Truck and RV, 510 Amigos Drive, Redlands, CA 92373, (888) 249-0124, (   has been good at troubleshooting this type of problem.  As for the hydraulic levelers, I have not changed my fluid but did need to add fluid due to a small leak.

Kitchen Faucet Replacement (Henry Fusco 1993 2400, acudoc888 at

I replaced my kitchen faucet with one I got on eBay that is much taller. Before, I could barely get anything under it since the sink is so shallow. When I removed the original there were three holes. Unfortunately Home Depot didn’t have a cover plate, just plugs for the holes. After installing, I noticed that the thin metal of the sink flexes some. Should have found a top cover plate or braced from the bottom. Great improvement – I can even fill pitchers now.

Blackwater Tank Problems. (Ken Harmon, IsuzuTrek at

After twenty years of use, the blackwater system began to give me problems.  Over the years I have replaced the blackwater valve 3-4 times but the last new valve I installed soon began to seep and the valve was hard to close at times.  I took the last valve apart and noticed the leading edge of the shutoff blade had obviously contacted something hard and was dented along the leading edge of the blade.  With everything drained and dried out, I looked up the pipe and into the tank using a remote tv camera on a flexible wand.  I could see no problems.

On our next trip I managed to hit a speed bump that was hidden in the shadow of a tree while going about 30 mph.  The resulting short flight rearranged all the cabinets and the contents of the refrigerator.  The next time I tried to dump the blackwater, the hose clogged but by moving it around it cleared itself. While at the FMCA Western Area Rally I attended a seminar on blackwater tank problems and learned a few things.  There is a deposit that can build up in pipes and the tank that is a combination of organic and mineral deposits. I decided to sign up to have my tank cleaned (~$150).

The equipment he used was similar to a pressure washer but at the end of the hose it had a head that sprayed the water out radially, almost 360 degrees but not quite. This tended to cause the head  to be  pushed to one side and made it maneuverable (it occasionally went unstable and pounded against the sides of the tank).  The spray pattern was also aimed slightly back down along the pressure hose so it tended to pull the hose into the pipe or tank and caused the debris to flow back along the path of the hose.  By manipulating, rotating and moving the hose in and out he could get the spray head to all parts of the tank, including the somewhat unique shelf in the Trek blackwater tank.

What came out surprised me.  Chunks of a rocklike material, some the size of a silver dollar and almost ½” thick.  One piece was large enough that if it turned sideways in a 4″ drain hose it would block the flow.  Other pieces had a radius like the inside of a 4″ pipe; some were the radius of the corners of the  tank along with pieces that were flat like the sides of the tank.  They had a consistency similar to very soft sandstone.  Since the cleaning I’ve had no problem with the tank system.

PS: Most of us know about the toilet paper glass jar test.  Just add water, a couple of sheets of toilet paper and wait 30-45 minutes.  Shake or probe the paper and see how well it has dissolved.  I have found a very large variation in the brands that are designed for RV and septic tank use.  Even different production runs of the same brand can have very different results.

Broken Co-pilot’s Seat Track

After the short flight mentioned above, I found we had a broken co-pilot’s seat track. When the track was removed it looked like it would be very difficult to repair.  The part was stamped ‘Made in Indonesia’ and was part of the original seat build in 1994.  I went online and in less than an hour found a source at RV Marketing Inc. I bought a set of tracks, Item #109031, $19.95.   (

 Ken & Cathy