wolfe10

Bill, Agree completely. One fact (coolant temperature) alone would never signal of excessive EGT in time, as coolant temperature rises much, much more slowly than EGT. Again, I am not an expert on how Caterpillar programmed their computer, but knowing engine RPM, boost and fuel consumption as well, repeat as well as coolant temperature, I suspect that they can predict EGT's pretty closely. I really wish a Caterpillar programmer could give us an overview of this, but seriously doubt they would allow us a look into their secret book. Suffice it to say, THEY are confident that unless the engine is modified, their programming will not allow it to "harm itself", but instead will de-rate to reduce HP/heat if it senses it is approaching a dangerous operating condition. Would be great for someone with one of these advanced engines to also monitor EGT's and let us know if, indeed, the engine is "self-protecting". wingman5th-- would look forward to your report. Thanks.

Well said, Tom. It is great to see first time posters come back, but as Tom said, many, many read but are too ?shy? to post. But, they still get a lot out of answers. Brett

Bill, Again, I am quoting a retired (i.e. real hands on tech) Caterpillar tech, not myself. But, I would speculate that the computer could monitor RPM, fuel, air/boost as well as engine operating temperature and get VERY close to what EGT's would be and could easily reduce either boost and/or fueling to keep the engine in correct operating perimeters. Agree, with a mechanical fuel system, particularly one that has been modified, monitoring EGT is important.

TandCAllegro, Welcome to the FMCA Forum. Yes, I drove a 2015 Ford chassis 34' coach with the Liquid Spring rear suspension at the Chandler FMCA Convention. Extremely impressive. Significantly reduced sway, bounce and softer ride. And, we PUSHED IT HARD, as most coaches handle fine when driven "grandma style". If you will be at the Indianapolis convention, the guy presenting the Suspension Seminar (yes, I normally do it, but our extended family is taking my dad for a cruise for his 100th birthday, so will not be in Indianapolis) is Wayne Wells, who works for Liquid Spring. Doubt there will be much of a sales pitch in the Suspension Seminar, but get to know Wayne and hopefully, he will have a coach like yours that you can drive at the convention with the Liquid Spring suspension.

Because I don't know the answer, I reached out to a retired Caterpillar tech. Here is his reply: Caterpillar does not give a spec for electronic C-7. Reason for this answer with electronics sensors, regulators , switches, the value of electronic components have a preset value that the ECM monitors. If a problem happens check engine light will come followed by engine reduced power ( derate ) then complete engine shut down. The time before electric engines checking exhaust temp was very popular. One thing to note as in this case turbo failure ( bearing failure ) the loss of oil into CAC in most cases rod bearing failure from lack of oil before heat build up. This is where all the electronic sensors come into play with engine ECM and shutdown. Just another add that Caterpillar has covered with electronic systems.

HWH jacks use either their own fluid or Dexron. The difference is that HWH's fluid is clear, so won't stain if it leaks. But Dexron works just fine (the red colored stuff).

Actually, best advice is to VERIFY what the OE fluid was for your coach. One of our DP's used Delo 400 15-40 for hydraulic fluid. Add ATF or power steering fluid and you would really screw it up!

OK, lets cover how to change the filters on the hydraulic reservoir. Main thing is to NOT just remove the over and reach into the oil and remove the filters. That will allow the unfiltered oil to get "past" the filters and go straight to the pump. SO, buy 5' of cheap 1/2" or larger ID clear plastic hose. Remove the lid. Use the hose to siphon off all the fluid from the outside of the filters. THEN, remove the filters. Replace filters and fill with the OE spec'ed fluid.

Agree, no question, this is NOT a pressure relief valve. The are on the OUTSIDE of the water heater. Drop the outside access door and you will see the pressure relief valve. OP's issue is on the back/inside of the water heater.

VERY, VERY likely the reservoir in the very back is for power steering, NOT jacks. Don't know what brand jacks you have, but all I have worked on have their own built-in reservoir with no filter. Many of the PS reservoirs also have filters in them-- yes, they need to be changed.

Agree-- what is the level in the hydraulic reservoir on the dipstick. Overfilling when cold will expend when hot and can certainly overflow.

Have you checked fluid level with the shift pad (assume this is an Allison 3000 series transmission)? And, by vent cap, do you mean the dip stick tube or something on the transmission? I agree with Rich, make sure you do not have coolant in transmission/ATF in radiator.

Please, back to: Adding Links to Text in a Post

Yes, we need to know if you have a 30 amp coach or 50? Plugging into 30 amp or 50 amp?

Is it ducted? Are forward vents open, bedroom vents closed-- that should help if you have ducted air. Bedrooms are very small. Depending on where the temperature sensor is, it can cause short cycling. Be sure the vents are not aimed at the sensor.

Two questions, as you are in some SERIOUS mountains: What are you driving/towing? How much experience do you have in serious mountains/very technical driving? Without answers to both, it would be really hard to give advice.

OK, the two routes that are a no go: 434 north from Mora is narrow, steep and under construction. 120 east from Ocate has an gravel section through the mountains. So your choices are (a little longer, but better roads) through Raton. Or a little shorter/roads OK, but not as good) through Springer and then 58 west. Have done both the latter two many times in our motorhome-- kind of a toss up. Either is just fine for any size RV.

While I agree, it could be some expensive item (PC board, gas valve, etc), I would sure start with the most common cause, one that takes no parts and only a few minutes to do-- the burner area tune-up. It includes: Cleaning the burner tube Cleaning and setting gap for the ignitor Cleaning gas jet Please do let us know what you find.

Peak torque is at 1,100 RPM: http://www.rvtechlibrary.com/engine/Cat_C9_Specs.pdf

Tom,

Roger, That would be quite shocking (pun intended). So, shore power does not come into the main 120 VAC breaker box and then breakers for refrigerator, outlets, roof A/C, etc in that box supply each appliance?? The reason that would be against code is that it is very doubtful that the wiring to the refrigerator is large-gauge. And, if wired directly to a 30 amp outlet, the wire, not a breaker or fuse would serve as the breaker/fuse in the event that there was a short at the refrigerator end. Said another way, there would be no 10 or 15 amp breaker protecting it.

Roger, If you are talking about the outlet that the refrigerator is plugged into, and provide it with 120 VAC from an inverter, it will "back-feed" the whole main breaker box unless the refrigerator breaker is turned off. The DPDT switch should be easy to install: All wires to have hot, neutral and ground unless the new inverter specifically says no ground. Choose a location near the refrigerator. Use an extension cord (male end only) that is plugged into the factory refrigerator outlet and wire it to one side of the DPDT switch. Run a wire from the new inverter to the other side of the DPDT. Then run a new wire from the DPDT to the refrigerator 120 VAC cord. Your choice if this is hard wired or a plug.

nadojan, Welcome to the FMCA Forum. Since it cools on 120 VAC, the cooling unit is probably just fine. When was the last time you did a "burner area tune-up"? Takes no parts and just basic tools. You might also tell us if this happens when parked or only when driving. And how far into the cycle does it get: Igniter clicks (you can hear it at refrigerator outside access door) Gas valve opens ( you can smell gas/feel the gas valve click open) Flame appears-- may have to remove the small tin cover to see it, but can probably look in from the side. Flame continues-- what size is it?

Where was it installed? The closer to the head, the hotter the acceptable temperature, so location is important in determining how hot you want to go.

OK, guys, back on track please. Thanks.