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Re: Biting the bullet (hard), I finally have my dream Coach - a 1995 U300 SE

Reply #125 – November 23, 2012, 11:33:39 pm

Well...another interesting day!  ( as a few of you have commented, this is one way to learn a lot about the Coach before it's road-worthy).

So this morning, I first re-connected both battery-bank negative terminals (after turning the inverter "off" at the unit). Entered the Coach, turned the master switch on -- turned the inverter on above the door. And I powered up one television, and also the micro-wave to confirm the A.C. function. Everything's good.

Then, I tackled this strange deal with the ignition switch not turning things off with the key "in hand". With the wiring diagram in front of me, and looking at the main ign. switch connector part of the drawing -- I saw something not quite right. All the wires are there, the proper color in the proper location -- except one. The black female spade terminal was not in the connector slot where it should have been according to the drawing. It was "one-off" in location . So I removed it with a teeny screwdriver, put it where it was supposed to be in the connector, plugged it back into the ignition switch and turned the key to the "on" position. Everything powered up, and then I turned the key "off" -- and lo and behold -- everything powered off. Hmmm.. somebody has been doing strange things in the checkered past the Coach has seen.

The clicking from the gen-set that I thought was the fuel pump (with everything off, the gen-set at a standstill -- was actually coming from behind the control panel -- like a relay clicking). It no longer does this since addressing the ignition switch wiring. However - I have had to use the breaker re-set button on the panel a few times now to get output from the generator (as then confirmed on the meter above the door). So -- that relay or whatever was clicking behind the panel, might have been weakened -- and will need replacing.

Okay..good. Time to move on. I fired the CAT on starting fluid for about 20 seconds (hooray! -- the first noise out of it since I acquired the beast). Then, after adding 10 gallons of fresh diesel -- I moved onto Gary O's recommendation of pressure bleeding via the main fuel tank (remember - I've a dead priming pump). With an assistant at the fuel neck, rag around the inlet and an air nozzle -- I first cracked the petcock on the primary filter and a steady stream of clean fuel ran out -- BUT-- then what caught me completely by surprise, a steady stream was also spraying down on the ground from a source right above the starter -- at the allison bellhousing-to-CAT block joining area, and where as it turns out -- is the connection of the fuel line to the inlet of the lifting pump. Ah Ha!

With a 1 inch wrench on the fitting there, it was loose. Unbelievable! -- who the heck has been working on this thing? Well -- that would explain air entering the system. (Still doesn't explain a frozen priming pump on the secondary filter housing, but) . I tightened the fitting, we re-pressurized, no further leak at that fitting --  and so moved onto the connection at the secondary filter housing  being cracked open (the outlet of this filter, couldn't get a wrench on the inlet) -- and...nothing.  Which makes sense in that the pressure normally seen there is after the lifting pump, and the pressure we were putting into the system via the tank inlet was 10X lower (if I understand it correctly the lifting/fuel pump delivers 90 psi to that secondary filter)

So -- here's the next series of moves:

1.) Change both filters (had not done that yet-- thinking I may have been able to fire it on the existing filters, and then change them out)
2.) Fill the filters with fresh fuel as the procedure calls for.
3.) Buy a new priming pump, remove the two bolts that hold it in place on the filter housing and fit the new one with a new gasket.
4.) Work the pump as called for to achieve a bleeding.
5.) Fire up the CAT.

Oh! -- as Gary O sent me via e-mail a concern about the electrical issues, and a potential electrical fire danger -- NO -- I never leave the Coach in-between these sessions of working on it -- with any batteries connected. I kill off all power each time -- after first letting the gen-set run on the "boost" setting to re-charge for an hour. It seems like common sense to me -- that until my confidence level is high enough that everything is working as it was originally designed to, I'll take the safest route.

The fun continues, and I'm learning ton's !!

Safe and happy motoring,

Michael

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Re: Biting the bullet (hard), I finally have my dream Coach - a 1995 U300 SE

Reply #126 – November 24, 2012, 12:29:29 am

I almost forgot!

Those of you with a similar layout of how the fuel feed line enters the engine bay might want to check this area out for integrity. for this was not properly engineered. My line has small cracks in the outside surface, and a kink in the hose as it tries to make the radius to the lift pump -- for two reasons. One -- it is too close to a heat source (the charge-cooler tube leading from the turbo is very near), Second, this fluid line has no strain relief. There should have been a heavy bracket at the transition into the rear bay with through male fittings. In addition, the line going to the lift pump inlet should have had a 45 degree fitting at the pump-end, instead of just bending the hose to mate up.

Something to add to my growing list.

Cheers!,

Michael

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Re: Biting the bullet (hard), I finally have my dream Coach - a 1995 U300 SE

Reply #127 – November 24, 2012, 02:31:20 pm

  Mike,  !!!  Please DO NOT USE  STARTING FLUID TO START YOUR ENGINE !!!  If you need to assist with any thing spray  "WD 40"  -  either (starting fluid)  will cause major damage to your engine.......

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Re: Biting the bullet (hard), I finally have my dream Coach - a 1995 U300 SE

Reply #128 – November 25, 2012, 12:54:46 am

WoW! -- I thought it was just an absolute "never-do" to use ether when the engine is hot. Well... I hope I didn't hurt anything. I found a genuine CAT prime pump today. It should be here Thursday, and so next weekend -- I hope to fire 'er up.

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Re: Biting the bullet (hard), I finally have my dream Coach - a 1995 U300 SE

Reply #129 – November 25, 2012, 07:34:47 am

  Hey Mike, Did you try putting that pump knob and cap in a vise. Clamp the cap and then using plyers carefully, see if you can get the knob to turn/rotate inside of the cap while it is off of the cylinder. That knob and shaft should rotate within the "Cap" that screws onto the cylinder...

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Re: Biting the bullet (hard), I finally have my dream Coach - a 1995 U300 SE

Reply #130 – November 25, 2012, 10:46:38 am

Mike,

I have owned several brands of diesel engines including our Detroit, Nissan, MBZ, VW and Case. The VWs and the Detroit will prime themselves with the starter. The Mercedes are only a bit more difficult but the Case can be stubborn without getting all the air out. The big secret will all diesels is to find all the highest points in the fuel system and then, cracking the line then pumping until you no longer see any bubbles at the fitting. With the Case, I have even slightly cracked one high pressure line at the injector and then operated the starter until it started, turned it off and tightened the fitting. This was with a rotary pump so your's should be easier with your Bosch style inline pump.

I don't operate the starter for more than 20 seconds and then if it has not started, I let it sit for a few minutes to allow it to cool.

There should be web sites with diagrams of your engines's fuel system with the air bleed points indicated.

Don't think you did any harm to your cold engine with the starting fluid. You could plug in your block heater for several hours before you try and start it. The warm engine will crank faster, compression/combustion chamber temp will be higher and the fuel spray pattern will be a little finer so it should reduce the cranking time and load on the starter. Several injectors will get pressure before others and with an engine that is a little warm, it will start to run on perhaps three cylinders a little sooner until the remaining injectors are primed and the cylinders start to fire several seconds later.

Pierce

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Re: Biting the bullet (hard), I finally have my dream Coach - a 1995 U300 SE

Reply #131 – November 25, 2012, 11:52:05 am

A couple points I feel need mentioned about now:
1-We never use either to start an any engine, First figure WHY it is a problem to start, we will use carb cleaner, much less violent. We use the 2+2 Berkebile carb cleaner, also a fairly good paint removed.

2-Engines that have been run out of fuel, from my experience, the 2 cycle DD is one that takes understanding, once the fuel pump is dry, you have to push fuel thru the system to get fuel into the gears of the fuel pump, (dry gears do not pump fuel), once you have a wet pump, yes it will force fuel thru the rest of the system and start fine with enough battery and starter.
Cummins and Cats are much easier to start, and just changing fuel filters, as long as you fill the new filter prior to installing, start engine, bring rpm to about 1200-1500 until if pushes fuel thru out the system and gets rid of any air pockets (about 45 seconds)
If a Cummins is run out of fuel, after you refueled, you will need to bleed the air, first at the pump, then at the injectors (B & C engines). There is many other ways of doing all this, but this is the quickest & simplest.
Brett can tell you all the info on the Cat fuel bleed setup, mostly use primer pump and open valve to allow air to escape.
Enjoy
Dave M

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Re: Biting the bullet (hard), I finally have my dream Coach - a 1995 U300 SE

Reply #132 – November 25, 2012, 01:46:03 pm

Gerry,

I've decided to not mess with the old pump anymore. I found a genuine CAT one in a sealed bag and original box on eBay for $55 (p/n 105-2508), and it's coming from Las Vegas. I should have it next Thursday. There were plenty of cheaper after-market ones popping up there, but I wanted an o.e.m. one. A lot of online searching here in the L.A. area did not come up with a "walk-in" location to buy one. Even though I'm sure a CAT dealer would stock it.

So -- new primary and secondary filters that I also already have, priming it, and it should fire up next weekend. The only unknown is that feed line into the lifting pump. It didn't leak when I tightened it (as I stated earlier -- it was actually only snug, not tight!) and then re-pressurized through the tank inlet, but I'll know more when it is running.

It's been like back-tracing through a "who dunnit" detective story, trying to find the clues and circumstances that led to it being a "non-runner" in that R.V Park in Irvine. A change of ownership of the Park relegated it to being moved to a tow yard -- where it sat for another 18 months before I found it through Craigslist. But it's slowly coming back to life and I'm happy with the results to date. The next check-out after getting the CAT going, is the Allison.

For you with the same vintage of Coach, is it normal when you first turn the ignition on and the red lights come on -- for one of them to say "Check trans"? -- I'm thinking it's just a check of the system, and it will extinguish when the engine actually starts (like a oil pressure idiot light does). Or -- it could be a stored fault code in the trans control unit. The fluid level is fine, and the color of the fluid is good. Of course -- I will change the filter before actually driving it any distance. Just hoping it is okay, and that when they moved it -- it was on a flat bed-- like the one they delivered it to me on. They said that was the case, BUT -- they also told me they removed the prop shaft (after I asked them if they did), and getting underneath there I could tell that was not the case.  Yes, I know I can take it to a Allison shop and get a data dump from the on-board computer, but that's in the future. 

Michael

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Re: Biting the bullet (hard), I finally have my dream Coach - a 1995 U300 SE

Reply #133 – November 25, 2012, 10:43:04 pm

Dave,

Pumps with gears are known as "positive displacement" pumps and are either rotary or reciprocating as apposed to a centrifugal pump and unless they have a lot of wear or bad seals, they should be able to easily suck fuel from the tank to the the engine. A gear pump in good condition can suck enough of a vacuum to bring water up 25 feet at sea level while a centrifugal pump needs to have water flowing through it before it can lift any water.  The same applies to diesel fuel but the lift distance would be different.

The roots supercharger on all DD 2-cycles is also positive displacement while the turbos on all of our Foretravels are in essence, centrifugal pumps.

Fortunately, air is compressible or a turbo would not work on top of the supercharger on the DD 2-cycles.

Good article on DD 2-cycle fuel pumps and priming at this marine forum: Detroit Diesel fuel pump prime (6-71,8V71, etc), by Genesis(6-71-8V71-etc)-by-Genesis

Pierce

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Re: Biting the bullet (hard), I finally have my dream Coach - a 1995 U300 SE

Reply #134 – November 26, 2012, 06:34:26 am

RE, Transmission light; Mine may flash on @ start up. but goes out almost instantly. other warning lights; Low air, level system, T.V. Antenna up, I think that's all.... 

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