Russ
11-12-2017, 06:31 PM
Hello fellow owners and enthusiasts. We are Russ and Gwen, new owners, first coach ever,,,,exciting learning curve.
New coach is 91 Le Mirage XL, 92 Marathon Conversion #9178 with 202K mi and a lovely DDEC II 8v92 Silver. We are fourth owners and bought it in a somewhat used hard and put away wet condition but it has good bones to build on and so the fun began a couple of months ago. None of the challenges we face will be news to those who came before, having all graduated from the same curve, but as a newbies we will have questions and will appreciate the educated responses that seem to result as we have noted while reading various posts as lurkers prior to registering as owners. We have owned, refit and maintained several yachts and sailed 50 thousand sea miles offshore in the past five years with all maintenance performed ourselves. The last yacht was a complicated 60 footer go fast dream with lots of similar systems to the XL so we have some basic skills and can work out most things. With a little help from you'all!
Our first move was to zero out the maintenance items, coolant triple flush, rad steam and new filters, same with oil, diff and fuel systems, flushed, changed, flushed changed etc until we had everything clean and current. The trani is next in a week or so. All this went well, lubed everything twice, new tag brakes, etc etc. Many many things have been repaired, replaced, updated and serviced. Going pretty good so far.
Recently fast idle stopped working but we did not go near that system as far as I can tell, hints there much appreciated. It is the Prevost/ Detroit system with the RPM rocker switch on the far left knee dash. It worked great till.....?
The level low ( the basic 4 solenoid [with one extra on a control valve near by] by Prevost) has issues, I am about to remove the manifold, all coils have resistance, left rear works as it should, right did work but has quit, front never worked. Will check for sticking valves once manifold is out then see where that goes. I have the switch exposed now and it seems to show resistance on all settings on the relevant posts with the key on so should be good, not sure how to see if there is power to all coils short of feeling when someone cycles the switch or using very fine pins on the meter? Any help there also appreciated.
Webasto, unit is new and system works great but the coach history reveals ongoing no heat in aft heat exchanger. This does not have a preheat engine circuit oddly enough. One loop runs fwd to the very front t-ed off to the galley and returns, the other t's off that outbound run on the way fwd and feeds down to both hot water tanks and the return comes back up and to the bath/bedroom exchanger, the one in question. It's exit T's into the common return line. That heat exchanger has zero flow. Removed it, flushed out, no issues, re and re and re and burp and re and burp and sounds like a workout program,,,decided the T on the return was back pressuring the inlet coming from the hot water tanks and halting flow with equal pressure. At some cost in skin loss and twisted fingers, swapped the T for a branch type Y thinking the exit line now blending ( not T,ing ) with the suction flow of the return line would pick up the imbalance. Wrong, still no flow, return from hot water tanks is hot right up to a foot away from the exchanger and when the system shuts down the return Y branch heats up via radiation from the hot coolant otherwise in and out are cool. Thinking of a boost pump coming up from the hot water loop? Burp hot water tank loop? Weird since it is simple flow but I am clearly seeing trees out there, we live in the woods but there is no forest in sight. Any revelations or hey stupid, on that item appreciated. No doubt others must have seen this as it is plumed exactly as per the Marathon layout and appears original. There does not appear to be a remote circ pump that I can locate. The Webasto in unit circ pump may be a bit shy on output to handle those loops? Can not isolate the hot water tanks loop as a test either as that is where the inlet flow to that last exchanger comes form. It is a pretty simple system.
There is the standard boost circ pump in the engine coolant/ heating circuit to increase flow to the driver area, all fixed and working as it should but not part of the webastard system.
Enough of that for now, the bunks have been removed and the restoration of the original bedroom is underway and calling for the next push. Previous owner was a Christian Rock band, is that an oxymoron, they gutted the bed etc and installed six bunks and she went down hill from there cosmetically and interior condition wise. On the positive side they HAD to get to the next gig and so spent a fortune at Prevost giving us the base to build upon.
Lastly, we totally Get It as to why Prevost owners are so enthusiastic about their rides. It's the ride! They are really really fun to go down the road. Thanks in advance for any guidance.
Russ.
New coach is 91 Le Mirage XL, 92 Marathon Conversion #9178 with 202K mi and a lovely DDEC II 8v92 Silver. We are fourth owners and bought it in a somewhat used hard and put away wet condition but it has good bones to build on and so the fun began a couple of months ago. None of the challenges we face will be news to those who came before, having all graduated from the same curve, but as a newbies we will have questions and will appreciate the educated responses that seem to result as we have noted while reading various posts as lurkers prior to registering as owners. We have owned, refit and maintained several yachts and sailed 50 thousand sea miles offshore in the past five years with all maintenance performed ourselves. The last yacht was a complicated 60 footer go fast dream with lots of similar systems to the XL so we have some basic skills and can work out most things. With a little help from you'all!
Our first move was to zero out the maintenance items, coolant triple flush, rad steam and new filters, same with oil, diff and fuel systems, flushed, changed, flushed changed etc until we had everything clean and current. The trani is next in a week or so. All this went well, lubed everything twice, new tag brakes, etc etc. Many many things have been repaired, replaced, updated and serviced. Going pretty good so far.
Recently fast idle stopped working but we did not go near that system as far as I can tell, hints there much appreciated. It is the Prevost/ Detroit system with the RPM rocker switch on the far left knee dash. It worked great till.....?
The level low ( the basic 4 solenoid [with one extra on a control valve near by] by Prevost) has issues, I am about to remove the manifold, all coils have resistance, left rear works as it should, right did work but has quit, front never worked. Will check for sticking valves once manifold is out then see where that goes. I have the switch exposed now and it seems to show resistance on all settings on the relevant posts with the key on so should be good, not sure how to see if there is power to all coils short of feeling when someone cycles the switch or using very fine pins on the meter? Any help there also appreciated.
Webasto, unit is new and system works great but the coach history reveals ongoing no heat in aft heat exchanger. This does not have a preheat engine circuit oddly enough. One loop runs fwd to the very front t-ed off to the galley and returns, the other t's off that outbound run on the way fwd and feeds down to both hot water tanks and the return comes back up and to the bath/bedroom exchanger, the one in question. It's exit T's into the common return line. That heat exchanger has zero flow. Removed it, flushed out, no issues, re and re and re and burp and re and burp and sounds like a workout program,,,decided the T on the return was back pressuring the inlet coming from the hot water tanks and halting flow with equal pressure. At some cost in skin loss and twisted fingers, swapped the T for a branch type Y thinking the exit line now blending ( not T,ing ) with the suction flow of the return line would pick up the imbalance. Wrong, still no flow, return from hot water tanks is hot right up to a foot away from the exchanger and when the system shuts down the return Y branch heats up via radiation from the hot coolant otherwise in and out are cool. Thinking of a boost pump coming up from the hot water loop? Burp hot water tank loop? Weird since it is simple flow but I am clearly seeing trees out there, we live in the woods but there is no forest in sight. Any revelations or hey stupid, on that item appreciated. No doubt others must have seen this as it is plumed exactly as per the Marathon layout and appears original. There does not appear to be a remote circ pump that I can locate. The Webasto in unit circ pump may be a bit shy on output to handle those loops? Can not isolate the hot water tanks loop as a test either as that is where the inlet flow to that last exchanger comes form. It is a pretty simple system.
There is the standard boost circ pump in the engine coolant/ heating circuit to increase flow to the driver area, all fixed and working as it should but not part of the webastard system.
Enough of that for now, the bunks have been removed and the restoration of the original bedroom is underway and calling for the next push. Previous owner was a Christian Rock band, is that an oxymoron, they gutted the bed etc and installed six bunks and she went down hill from there cosmetically and interior condition wise. On the positive side they HAD to get to the next gig and so spent a fortune at Prevost giving us the base to build upon.
Lastly, we totally Get It as to why Prevost owners are so enthusiastic about their rides. It's the ride! They are really really fun to go down the road. Thanks in advance for any guidance.
Russ.