This is a long and unnecessarily tedious explanation of our recent repairs. For those that want the short, tl;dr version: We spent four nights in the parking lot of Interstate Power Systems while they repaired five of the eight thing we asked them to look at, including the two most critical items. We simply ran out of time for the other three. We have had previous repairs that at first we thought were great, only to discover shoddy workmanship as we got down the road, so I don’t want to sing the praises of Interstate Power Systems just yet, but so far things are looking good and we will update along the way. On to the details…
It was incredibly frustrating to finally get our bus back after nine weeks of repairs in Colorado only to have it break down again within a week. But we had high hopes that Interstate Power Systems would be a good fit to take care of not only our latest problem, but perhaps some other issues as well, some of them having plagued us for months. They didn’t balk at the age of the vehicle, they prominently displayed both Detroit Diesel and Allison Transmission signs on their building, and seemed to have a cadre of deeply experienced specialists to address our multiple issues. We gave them a prioritized list of eight items to examine:
- Failure to start problem, possibly due to a fuel line air leak allowing fuel to flow back into the tank during overnight stops, making starting difficult.
- Alternator/Generator failure to charge starter batteries. A long term problem that had once been sporadic and was now constant.
- Speedometer/Odometer failure, which began right after B & G arranged the transmission rebuild.
- Transmission or Engine Oil leaks, possibly both.
- Coolant temperature gauge inoperative, long term problem that had given us difficulty during uphill climbs starting in Idaho.
- Parking/Hand Brake way out of adjustment, barely useful.
- Oil Pressure gauge reading low despite oil pressure having been verified correct directly at the engine low point.
- Left low beam headlight inop despite bulb replacement. Works when high beams are on.
When we arrived Tuesday afternoon Interstate had no open bays available until the next day, and the right mechanics for our specific problems were not available yet anyway. Critically, they let us stay in the bus overnight, so long as it was in the parking lot rather than the actual repair bays. They even allowed us to hook up to a heavy duty electrical outlet: not enough to run our rooftop A/Cs in heat mode, but enough to charge batteries, power the refrigerator, make coffee, and cook. They even gave us guest access to their wifi for the duration of our stay.
The next day after lunch they pulled us into the hanger style building amidst the tractor trailers, dump trucks, cranes, and other assorted big rigs. They divided our punch list between two experienced techs: John, the two stroke diesel engine expert would handle the starting problem, Leroy the electrical expert would deal with the alternator issue, with the rest of the list addressed between the two as time allowed. Here is how it turned out:
Fuel line leaks and difficulty starting: Fixed! John undertook one primary repair and half a dozen related adjustments.
- Inspected all fuel lines, and found a leak at the input check valve. Replaced check valve, and installed another on the return line as well.
- Adjusted idle RPMs from about 470 up to about 650. Significantly smoothed out the idle performance, nearly eliminating cyclical revving.
- Changed two of the four air cleaners (filters). They were filthy. Only two were available locally, I will have to change the other two myself.
- Adjusted throttle linkage allowing more throttle travel from the foot peddle, should give me more power at the top end.
Alternator failure to charge the starter batteries: Fixed! With the wiring diagrams from my manuals, Leroy began trouble shooting, and fortunately confirmed that the very expensive to replace alternator was doing just fine. He then determined that the voltage regulator was fried, as well as an associated sensing relay. Interstate Power Systems parts department was exceptionally aggressive, finding U.S. Coach in New Jersey, an old bus parts specialist, that had the relay sensor. Though they did not have the voltage regulator, they had the circuit boards from inside the regulator. Good enough, they fed-ex’d both parts overnight. Once the parts arrived, Leroy was out on another job, but left instructions with young Craig, who installed the circuit board and components.
Speedometer/Odometer: Fixed! John pulled off the speedo/odo assembly from the body of the transmission housing and found that whoever did the rebuild did not reinstall the key into the rotating cable housing at all. Working with parts department, he found a very similar key with a slightly larger head circumference and ground it down to fit.
Transmission and Engine Oil leaks: Three out of four fixed! John suspected four different leak areas. Around the cover plate gasket of the transmission, a plug access point at the bottom of the tranny, the engine oil pan, and the radiator cooling fan hub. He skipped the cooling fan since he felt that would be an involved process with parts acquisition times that would be better suited for us to address when we were perhaps back in Florida. He tightened the oil pan bolts, which he described as extremely, loose. He wrapped the transmission access plug in sealant tape and added some sealant “goop,” thus eliminating leakage. Alas, it was the transmission cover plate that was nearly our undoing.
I mentioned to him that I thought that one of the mechanics with whom I had discussed the leak might have suggested that the cover plate bolts need to be re-tightened after an initial run time. He thought that absurd, but then proceeded to tighten them down with his torque wrench set to around 30 foot-pounds. He was surprised to find that several of the 19 or so bolts really seemed to need that tightening.
And that’s where the trouble began. In addition to the cover plate bolts there are two pull out bolts along the rim, the removal of which allows the cover plate to be levered out with the right tools. One of them had a big glop of sealant all over it, clearly indicating a jury rig fix. What we would later learn is that the gasket near this pull out bolt had failed, and either the tranny shop in California or B&G in Colorado had “fixed” it not by replacing the gasket, but by filling the hole and covering the bolt with a big glop of silicone type sealer. Tightening down the cover plate bolts had shifted things just enough such that the cheap sealant fix no longer plugged the gap. John confirmed this by removing the bolt and spraying cleaner liquid into the hole, watching as it spewed right out of the cover plate gap that should have been blocked by the gasket.
Now we faced a choice: wait until the next week when maybe they could bring in an old Allison transmission guy to assist (the concern being that pulling off the cover might require some specialized tools and knowledge) and then wait until the gasket could be acquired? Or go for a somewhat more elegant attempt at the same jury rigged fix as the previous jokers had done, although this time at least with my full knowledge. We went for the latter. It was Friday afternoon already, and I figured that the gasket and gasket sealer would be compatible, and besides we would let it sit overnight to cure and then run a solid test in the morning. John pressure forced some of the gasket sealant into the removal bolt hole until he could see it seeping out from the area where the gasket should have been. The next morning upon testing, I found no leak at all.
Coolant temp gauge: Not fixed. John and Craig determined that not only did I need a sender unit and possibly a gauge, but I also had a break in the wiring somewhere. They left it up me as to whether to proceed with running new wiring through the bus, which thy could not get to this week, or living with it until I could address in Florida. I chose to skip it for now: I still had my jury rigged engine gauge that got me over the Colorado passes.
Parking/hand brake adjustment: Fixed! I’m gonna take a little credit for finding the specific adjustment procedure and making John read it rather than have him crawl around under the bus, which seemed to be his preference at first. Once he read the procedure, he had my almost useless parking brake adjusted to perfect working order in fifteen minutes.
Oil Pressure Gauge reading low: We simply ran out of time to address this. Another day…
Left Low Beam headlight failure except when High Beam switch is on: Not fixed. The problem is intermittent: the day I asked them to look investigate, it did not manifest, the lights worked fine! Three days later when I was ready to leave it failed to work. Ah well, another day for this as well.