Testdepth

I am interested in more info. I have a 96 Windsor with the King setup. I seem to be having some intermittent issues but it is at least still working. Also my cruise control just died on my last trip. So it’s probably time to start looking for an alternative! thanks, Mike 96 Windsor C8.3 Mechanical

Interesting, I’ll see if our does that as well.

Sort of related… Question: what is the difference in the 2 positions of the water pump switch. In my ‘96 Windsor both positions appear to do the same thing. Mike

Thank you. Big job. Glad it’s behind me!

‘96 Monaco Windsor, C8.3 Decided to troubleshoot “Kool-Matic doesn’t work”, statement by PO. Ok let’s see what it even looks like! Open the grate, 2 wires hanging there! No motor or fan or squirrel cage or anything, so I still don’t know what it is supposed to look like. I called a couple of used parts places with no luck. Has anyone replaced it with something else? It appears that it might have been just small dc motor with a fan attached?

I did call Scott and had a nice conversation with him. Based on his comments that the regulator itself is a very low failure item I decided to pull the regulator back off to ensure I hadn’t messed it up. I did and found the main piston apparently had some crud in it that I didn’t find before or was in a hose. I recleaned and assembled with lots of atf and made sure everything was smooth and free. The problem appears to be resolved.

I haven’t updated this thread in awhile so thought I would do that. I did install an EGT (preturbo) and ran with it for awhile to see what my temps were doing. Ran some tests by installing a needle valve in the pressure line to the waste gate and varied the setting from normal to completely closed. max boost never changed. To me that pointed to bad/worn turbo or leaky charge air cooler. With only 75k miles on the motor I opted to check the CAC. I built a test fixture I found on YouTube and tested the CAC. Could not get it to pressurize! Long story short, found a failed weld with a hole about 3/16 x 5/8”. TIG welded it closed, tested found a couple of pinhole leaks that weren’t weldable so I epoxied them. Retested reinstalled CAC and on initial test drive was able to achieve just over 20# boost. I’ll be doing a more extensive test drive to include some longer steep grades to watch boost and EGT.

Greg, I did finally find the technical info I needed and your shocks will not fit my coach. That's too bad, that is a nice deal! Thanks, Mike

I am on the web trying to find new shocks for my !996 Windsor. If they will fit my coach I will Paypal you right now. My problem is trying to determine which Bilsteins will fit! Mike

Thank you Jim. I will give them a call. mike

96 Windsor, C8.3/275hp. I have a hydraulic fan motor that the regulator is not functioning correctly. When I got the coach it was leaking pretty badly and would cycle fan speed somewhat erratically, but was essentially working other than the leak. (a small puddle where ever I stopped). I drained the system, the ATF was a little dark but wasn't burned and removed the control valve unit. disassembled it and found one smashed O-ring one machined opening that was empty and another o-ring in good shape. The machined opening appeared to be for a crush washer or similar type seal. I replaced the 2 O-rings that were there cleaned the whole unit and reinstalled. the leak stopped but now the regulator works even worse than before. I can find no mfg. name on the unit anywhere and no one at any of the truck places near me that knows anything about them. Is there anyone on the forum that knows anything about these or a former Roadmaster employee that might have some documentation on this crazy unit? I'm pretty certain it just need the correct set of seals etc and it would be back in business. I would appreciate any help/knowledge anyone could provide. Mike

In the end it appears that your comment on oil is likely the culprit. If I fill the tank completely full, (till liquid comes from the vent) I have the problem with the genset and cook too. If I only fill to 3/4 every thing is fine. I ended up changing the filter in the solenoid valve and the main regulator in the process. I also ended up pulling the genset out and doing a full cleanup of all the fins which had a lot of dirt packed in. Also discovered the genset is set up to accept liquid propane if you wanted to do that. this winter I will figure out how to clean out the tank or replace it.

I just added EGT to my ‘96 Windsor C8.3 as well. Discovered very similar readings, however was a bit alarmed that temps immediately jumped to over 1300 going over mountain passes in the northwest. I had to back off the throttle to keep temps in the 1200 range. Totally stock C8.3/275 HP engine w/70k original miles. Assuming the new gauge is accurate that is very concerning that it would be very easy to generate damaging EG Temps.

I think that is my next step in this whole process is to test what the turbo will do with the hose disconnected/pinched just to see if it tops out at 17# or it goes higher. I’ve also researched a few EGT gauges and will pull the trigger on that before making any decisions on fueling changes. I too believe that I probably was up into the 1300-1400 range on my pickup before I chipped it. The “chip” was actually a 10 step programmer that went from 0 (not turned on) to 9 ( max fuel). The kit came with a pyrometer to measure EGT. When running on zero, supposedly turned off I seemed to have a bit more power but I could run the EGT right up through 1300 where the alarm was set. That was running it like I had prior to any adding anything other than the pac brake I added. Bottom line was I ended shifting down earlier and pulling hills a bit slower than I had before. Not what I was looking for!

Van W, thanks for info. I too discovered some of the same info you are relating here on a ‘02 5.9 that I chipped in a pickup. I pulled a 3 axel goose neck with a 30’ boat and discovered to keep EGT under 1200 was not easy. 1200 degrees was the number that I kept hearing being tossed around as the short term high limit and that 1100 was the steady state max. The other area I’ve yet to explore is boost. The max boost I’m able to obtain is 17 lbs. I think that is low. I’d like to experiment with getting that into the mid twenties even before installing a new plate in the pump or injectors. I don’t know if the waste gate is actually set at 17 or that’s just all that amount of fuel will produce.

Agree 100%. I’ve had 2 previous diesels that I “chipped” and exhaust temps really soar when you start pouring the fuel to it. That creates another problem; my other rigs had direct reading pyrometers. Not sure how a pyrometer is set up when there’s 30+ feet between the exhaust manifold and the dash! Hopefully it’s a wire feed and not the tiny copper sense line! Also what are people using as top exhaust temps? Both my 5.9 Cummins and 7.3 Ford was recommended at 1100 deg. Is that still a good number for an 8.3 Cummins?

Haha! Yeah I realize that, and I’m not looking to go screaming over the divide at the speed limit. My last trip over the hill east of Butte on 90 I was down to about 40-45. That’s without a toad and not even loaded heavy. This past weekend I went over White Pass in Washington and was down to about 40. That’s not as much of an issue since since it’s a 2 lane. I want to find a small toad and that’s going to just make it worse. So far in my research it looks like a different throttle plate in the pump and possibly new nozzles for the injectors would give me probably 75 Hp or so and about 100 lb ft more torque. I’m thinking this is really all I want or need to accomplish what I’m looking for. Mike

Excellent info. I will definitely check with them.

Yep, that’s something I’ll have to keep an an eye on. As much as I can tell the radiator stack on the driver’s side is clean and not plugged up at all with dirt/mud/oil so hopefully it has the capacity for a few more HP. I would assume the 300 and 325 versions used the same radiator. So I haven’t found any electronic solutions that will do anything. Pre 1998 I believe the 8.3s were all mechanical so there’s nothing electrical that would help that I’m aware of. Improving air flow either through air filter or exhaust can help somewhat if there’s restrictions now. still looking! thanks for the reply. Mike

Yeah, that’s my ultimate plan, but thought I’d ask here to see if anyone had done something that worked well for them. I know that Cummins made a 300hp version of the same engine and I believe a 325 as well. Don’t know if those were just pump adjustments or full new injector replacement and pump adjustment.

96 Windsor, C8.3, 275hp. I’m looking to add a few horsepower and torque without breaking the bank and without having to do any kind of transmission upgrade. The C8.3 is the model before ISC 8.3 so little to no engine electronics and a P7100 pump. With the current power I would be a real hazard on the mountain passes in the West if I had a Toad on behind. Currently I can maintain close to speed limit on not so steep grades. Has anyone done any upgrades and what we’re your results. thanks, Mike

I have the same coach and had similar problems when I got it. Determined it was definitely the regulator, external by the way. The regulator was new but was a terrible replacement job. Replaced the terrible wiring job and everything functioned as normal. BTW the external regulator is near the alternator mounted on back wall driver side. Picture attached. Mike

If one end is hooked to the water system and the other end has a valve cap identical to a tire, it is your accumulator tank which maintains water pressure and keeps your water pump from cycling so much.

Jeffrey and Rik, thanks for your inputs. After looking at the ambient temp vs pressure chart and extrapolating down a bit, it appears to me that I’m still a bit low but not by a lot! From here I’m going to pursue leak detecting and just use it till our ambient temps get a little higher and then compare to the charts to see how it looks then. BTW, pressures this am, 50degree ambient temperature, were about the same; 10-15 low side 100 high side. We’re supposed to get to 70 in the next day or two so I’ll do a check then to see if I get any increase in pressures. thanks again. Thanks Rob. I think Troubleshooting with outside temps so low makes it a bit more difficult. When our temps get a little hotter I should be able to get a better idea of how the system is working, and hopefully a more narrow temp swing. mike

So a little more info I’ve discovered. This coach has been sitting pretty much unused for the last 4-5 years so it’s quite possible compressor seals are dried out. After putting in is out 16oz of Freon my compressor did kick on and I had decent, ~ 20 psi lp side pressure my high side pressure was only around 100. I put an additional 12oz can with the stop leak in to see if I could get my high side pressure up thinking I’m just extremely low on Freon for so much piping. At this point I have 42 degree air from the center vent in front. Lp side at about 10 psi and Hp side still 100 psi. Now I take a drive and watch temp at vent. 60 degree outside temperature. My vent temp goes down to 31 deg. stays there for awhile the slowly climbs to 47deg. then cycles back down to low 30s. Continues this for the trip through the mountains where outside temp drops to about 50. Should there be that much range in the temperature and is this even a valid test with such low outside temperatures? Also with such low high side pressure I’m wondering if the compressor is weak. I will put gauges back in today to see if pressures are the same and tonight will start looking for the leak since I put dye in yesterday. Thank you for the responses regarding pressures and possible leak points. I checked my piping path and it appears it stays on the opposite side of the engine from the turbo, but I know one line has to get over to the condenser in the radiator stack on the left side so will trace out that line today.