Prevost Webinar on Winter Prep – Heating System Maintenance

So I thought I’d post some notes from the recent Prevost Webinar I attended on Nov. 4th.  This Webinar covered Winter Preparation – Heating System Maintenance.

The following items were covered in this webinar:
* Battery systems
* Booster cables to jump start
* Engine cranking
* Preheaters
* Coolant
* Pneumatic system issues

The first comment was SAFETY – more critical in winter conditions.

Battery systems – Group 31 (4) (most common) or 8 D
– Ignition & battery switch are one in the same
– Volvo 9700 – separate battery switch to left of ignition switch

Main difference is physical size and they are cabled differently

Proper cabling is crucial
– 8D – cabled in series – reserve capacity and cold cranking amps need to be the same
– Group 31 – more connections – engine and transmission wires are smaller wires

Proper clamping

Booster cables to jump start
– use booster stud – do not jump directly to battery  (on ’94 & up)
– (-) negative on post (located on frame), (+) stud sticks up from battery
– * do not make a connection w/ donor vehicle running – connect 1st, then start donor vehicle

Engine Cranking – do not crank starter for more than 15 seconds
– starter motor needs fixed voltage
– volts x amps = watts
– as voltage drops, amps through cranking motor increases
– so, lower voltage = higher amps through starting motor and cabling system

Volvo D 13 Engine – No Ether!  Can cause engine damage on air intake heater.  Auto at 54 degrees F coolant or lower

Preheaters – Concentration: Webasto / Spheros (separate company)
– when preheaters are run year round, less problems

– Webasto: DBW 2010, DBW 2020
– rare that air shutter needs to be adjusted

– Spheros Thermo 300 – approximately 102,000 BTUs & has computer interface

Info on these preheaters can be found on the Prevost website under Parts & Service →Tech. Manuals→Manufacturer Publications.

Preheater not working?  Is it a Prevost issue or a preheater issue?
There is a difference between “Switch On” & “Start Up”

If the preheater does not “switch on”, then it could be a Prevost wiring problem.

Check wire 127 A (there were several diagrams and schematics shown throughout the webinar presentation)

* Run preheater every month
– Fuel nozzle replacement
– Flame detector (can get dirty) – there are 2 types

Webasto: disc
Spheros: rod

Understand operation – see shop manual on website
– filter screen on fuel pump

Information on correct coolant can be found in the operation manual, the maintenance manual, and on a decal by surge tank.
– Volvo is different from Detroit Diesel
– D13 – extended life coolant only

Coolant filter – strainer on supply line to heater control valve on evaporator to heater core

Pneumatic System Issues
Tech under coach – use safety glasses

The following needs to be done in the proper order
Run engine on fast idle 1st.
1) wet tank – drain completely
check brake tanks for proper psi*
2) primary brake tank
3) secondary brake tank
4) accessory tank
5) needle recovery tank

* 120-130 psi = check valves o.k.

note any moisture – air dryer may need to be serviced

Check schematic for particular vehicle tank locations.

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3 Responses to Prevost Webinar on Winter Prep – Heating System Maintenance

  1. Pingback: 2010 in review « Affordable RV Solutions

  2. Heating and System maintenance is a great subject to blog about; thus helping many RV owners.. Great Work..

    • Our hope is to not only provide excellent service to our customers, but also to inform all RV owners about important information necessary to properly maintain their coach. If you have any additional items you would like to hear about, please let us know. Thanks.

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