Temps

[Mike McMahan]

Thanks everyone for the responses. Pete you were right about the
retarder. I guess my old age and senility set in and helped me to
get my two coaches mixed up. I had not verified what the second
small radiator(it does have two electric fans mounted on it) did.
I'm going over to the bus this afternoon and will look. I have not
ever removed the outer grill that covers the radiator. If memory
seves me correctly the only fastener that I see on the outside of the
grill is a pop rivet at the top. What is the procedure for removing
the grill to clean the radiator? Thanks again, MIke Mcmahan 96 42'
Wanderlodge


--- In WanderlodgeForum@yahoogroups.com, Pete Masterson
wrote:
>
>
> ===============================================
> Pete Masterson, Author of
> Book Design and Production: A Guide for Authors and Publishers
> Aeonix1@...
> Aeonix Publishing Group http://www.aeonix.com
> ===============================================
>
>
> On Jun 17, 2008, at 10:46 PM, Glenn Allen wrote:
>
> > Pete,
> >
> > Good Summary. Can you or someone elaborate on the following
> > questions I have about the areas of your post noted below relative
> > to a 1986 PT-40 6V92.
> >
> > Thanks,
> >
> > Glenn....(see questions noted below your comments):
> >
> >> The transmission cooler is in the bottom of the
> >> water radiator. The other radiator you see is not the
> >> transmission cooler. (I don't think it even has a fan.) The air
> >> flow through the transmission cooler is from the main radiator
> >> fan.
> >
> > 1a) There is a small radiator attached on the outside bottom left
of
> > the main radiator that has hoses running to the power stearing
fluid
> > cannister. I assume this small radiator is cooling the fluid for
> > power stearing and the hydraulic fan. There is also a round
> > cannister down low that is between the driver's side of the engine
> > and the main radiator with large diameter (3"+) hoses from the
> > radiator and engine. There are also lines from the transmission.
> > I'm assuming this is the transmission heat exchanger. I would
> > assume water is flowing from the bottom of the radiator to the
> > transmission cooler and then to the engine. Is this correct?
>
> I'd have to go out to the coach and take a look. I don't recall
the
> "canister" you mention (it might be there, but I don't recall it).
> The bottom (1/4 or so?) of the water radiator is a radiator for
the
> transmission fluid. When my radiator core was removed, there was a
> 'stub' radiator for the transmission fluid. The new core attached
> above it. I no longer recall if water moved through some of the
tubes
> and transmission fluid moved through the other tubes or exactly
what
> the physical arrangement was.
>
> The second small radiator is for cooling the power steering (and
may
> cool the hydraulic fan fluid as well). The power steering
reservoir
> is a large canister on the curb side visible through both the rear
> and side doors. Do not overfill it. If you do, it will coat
> everything nearby with oil. (And I'm not going back to that place
for
> service again.)
>
> The fan pulls air through a 'stack' of radiators. You can remove
the
> grill on the street side and you'll see (I'm going by memory here,
so
> bear with me) the AC condenser, and the Air Charge cooler. Behind
the
> air charge cooler is the regular water radiator with the
transmission
> radiator in the bottom portion of it. You can't see the water/
> transmission radiator since it's fully covered by the Air Charge
cooler.
>
> Looking from the inside, you mostly see the fan and the metal
shroud
> that makes the fan more efficient.
>
> > 1b)I notice on this transmission cooler there are plugs on each
> > end. Do these plugs drain the water or transmission fluid from
the
> > heat exchanger (or maybe both)?
>
> Afraid I don't know. I have a 400+ page DD Series 60 manual (as a
> PDF). Perhaps I can make a copy available to you if you'd like. (I
> bought a CD with it on eBay.) I don't know if this manual
discusses
> the radiator set up in the coach (bus) as it's mostly focused on
> heavy truck installations. More likely this is covered in Allison
> documentation -- I don't have any of that stuff beyond the owner's
> manual.
>
> >
> > 1c)Should this transmission cooler be cleaned or serviced?
>
> The transmission fluid filters should be changed every 36 or 48
> months depending on the size of filters you have. (I have to check
> this.) These are located in the transmission 'pan'. When the
filters
> are changed the transmission fluid is also changed. Use a
synthetic
> transmission fluid (I have Transynd). I don't think there's any
> specific service required for the cooler itself. You change the
> transmission fluid on the same interval as the filters. With an RV
> you're going to probably "time out" rather than exceed the
suggested
> miles.
>
> Change the engine oil (and filters) every year or 15,000 miles,
> whichever comes first. A full oil change will take nearly 40
quarts
> (10 gallons) of oil. You can use a synthetic, if you wish, but the
> change interval is the same. I have Rotella or Delo for heavy duty
> diesel engines.
>
> There is a canister on the curb side that holds about 3 gallons of
> oil and there's an automatic oil add system (requires air pressure
to
> operate), if needed.
>
> >
> >> I think it comes on at 190 or so ... or whenever you turn on
> >> the "fan override" switch
> >> or turn on the dash AC.
> >
> > 2a) I believe my fan is "always on". When the engine temp is
cool,
> > the AC is off, and the fan override is off, should the fan be
> > turning at idle speed or stationary?
>
> The fan should be not turning or turning very slowly at idle speed
if
> the engine isn't fully warm. They fan will run at full speed if
> _either_ the "fan override" or AC switch (the little button on the
> automotive heat control panel) are on.
>
> >
> > 2b) Is the speed of the fan proportional to the engine RPM?
>
> Not that I'm aware of. I think it has two or three speeds.
Frankly,
> I've never paid much attention to the fan when it was operating.
I've
> verified that it works and I've seen the clouds of dust it kicks
up
> when it's on, though.
>
> >
> > 3b) Where is the relay that the fan override switch controls?
>
> Front load center, SK 68 is the fuse. Relay K39 says "Chassis A/C
> Eng. Fan Enable" -- I don't see any other relay related to the Fan.
I
> suppose that the fan override switch tickles the same relay as the
AC
> switch.
>
> There area two other main Load Centers. One is behind the cabinets
> above the dashboard (on the right). The cabinets have a false back
> that pulls out, revealing the TV aerial wires and a load center.
> There's also a load center in the rear closet on the street side
> behind a felt-covered door.
> >
>