dougmac
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Re: CAT 3126 No Start
To troubleshoot the problem you have, its best if you have the diagnostic software to view the IAP (Injector Actuation Pressure). The most common not start I see on this engine is high pressure oil leaking by the injector o-rings. This causes low IAP. To check the o-rings. I remove the valve cover and crank the engine. If I see oil leaking out between the injector body and cylinder head, the o-ring on that injector has failed. There is some oil in the area around the injector all of the time so, you would be looking for one that had an excessive amount of oil forming around it.1KViews0likes0CommentsRe: Strange tire wear pattern
tmmar wrote: I noticed a strange wear pattern on the front tires of my 2008 Berkshire 390BH on a Freightliner raised rail XC chassis. There seems to be a small, concave 'groove' that is wearing on the inside and outside edges. I thought that it might be under-inflation, but according to the charts, I am right at the recommended pressures for the weight on the tires (LF tire is at 97 lbs, weight is 4830, RF tire is at 96 lbs, weight is 4510). Not sure why the tire is wearing this way. Any ideas? Thanks, Tom I have attached pictures that I hope will show what I am trying to describe. Tires are Michelins size 255-80x22.5 tire pics It appears to be normal wear for long wearing heavy duty tires. I know it hard to ignore because it looks like something is wrong. There is very little that can be done to prevent it.315Views0likes0CommentsRe: SOS stuck in campground Allison down
Open Circuit "G" solenoid. (forward clutch solenoid) I suspect a 1992 has the two connector ECU and the 24 pin rectangular pass through connector on the transmission case. I would examine the pass through connector paying close attention to F-1 pin (top row 6th position over) that will have a white wire #104 connected to it. That is the problem circuit. To determine if its inside the transmission, on the transmission case connector, check resistance between the F-1 (top row 6th position over) and the C-2 (middle row 3rd position) terminal. There should be around 3 ohms. If that checks ok, then you most likely have an an open in the chassis harness. The suspect wire would be, wire #104 (white) that goes between the F-1 pin on the transmission pass through connector and the A-4 pin on the blue ECU connector. Good Luck, Doug289Views0likes0CommentsRe: Ultra Low Sulfur Diesel
wolfe10 wrote: Interesting, as Caterpillar and Cummins both in writing say all their engines are OK on ULSD with no additives. And if ULSD is such a serious problem, one would think that the OTR truck would be stopped all along the side of the highway with issues, as they do a LOT more miles with the same engines that we use. ^ X2588Views0likes0CommentsRe: Help check trans light we're stuck
It sounds to me like your ECU is getting back-fed from another source through an open ground circuit somewhere. I would start by checking the integrity of the grounds. Another possibility would be the harness is shorted to a voltage source somewhere. I would also inspect the harness looking for a short. Also check to be sure your chassis voltage is under 15 volts.197Views0likes0CommentsRe: Allison tranny service light - Throttle Position Sensor Low
Code 22-12? The ECU is receiving a voltage signal that is below normal. There are several possibilities: 1-The sensor is miss-adjusted into the error zone. 2-There is a shorted or open circuit on the signal wire (156 blue) or the TPS high wire (124 red) 3-failed TPS 4- a very remote but possible chance that the ECU is bad. Five volts should be supplied to the sensor on the 124 red wire. As the TPS is cycled through its range the voltage on the 156 blue wire should vary. It should no go below 0.5 volts.324Views0likes0CommentsRe: Engine Down! Cummins ISB
It is possible that it has had some kind of a front gear train failure. The oil pump and fuel pump are both driven off of the timing gears. Unfortunately, if it has experienced a failure that would allow the camshaft to come out of time with the crankshaft, you may have damage to the valves. Good Luck Doug555Views0likes0CommentsRe: P30 wheel bearings
mike brez wrote: Thanks Doug. I have wheel simulators so I have to take the lug nuts off anyway. The cap is pretty deep into the hub with very little room all around. There is no way to pry it off with a screw driver. Is there any special tool that will take it off? Just googled and found This Its been over 10 years since our P30 buses have been gone... I don't remember exactly how i took the danged things off?374Views0likes0Comments
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