GMC Western States

 Tech Center Number 23 - November 1998

Roundup Tech Seminars
by Chuck Garton

The Hope roundup covered a number of interesting subjects. Those of you who could not attend and are interested in these topics can contact me for more information.
The seminars began with "Sealants and More" with Gord Evans of O'Connor RV Centre Ltd. in Chilliwack BC. Gord gave an enlightening session covering the use of sealants available and what to use where. Especially noteworthy was "Sikaflex-221". This acts as both a sealant and glue. He also mentioned "Geocel Proflex' that works under water and can be used during a rain storm{
Bob Cook and Chuck Garton followed with an update of their Prescott seminar on used parts available from junk yards.
Next Blue Ox demonstrated their towing equipment currently available.
Bill and Marilyn Harvey followed with window coverings. Bill began the session with the theory of heat transfer which led to techniques to keep our coaches cool or warm.
Chuck Garton concluded the tech seminars with some modification ideas to improve and modernize our coaches:

1. Providing a way to drain the oil from the area forward of the drive axle
2. Rerouting the sewer pipes and adding a macerator pump
3. Installing a 400 Watt inverter to run the refrigerator on 110 VAC on the road from the alternator.
4. Fuel tank modification by removing the socks from the pickup tube in the fuel tanks and repositioning the pickup tubes
5. Adding a relay to the house fresh water pump
6. Installing a light that comes on when closet doors are opened
7. Updating AC-DC converters to current technology which substantially increases the charge current and truly charges the battery when on shore power

Remember: What you do to your coach is your responsibility. Nobody else is responsible!

Transmission Venting Simplified
by Bill Harvey

Most of us would like to be able to direct any overflow or "burping" of our transmission {trany) away from possible contact with the hot exhaust line in the immediate area. This burping is suspected of being the culprit in many coach engine fires.
Thanks to Paul Burkhart, of the GMC Mountainaires, a trany vent can be installed without dropping the trany. The following tools and materials may be used to do this:

* Thin 1/2" open-end wrench
* 1/4" nut driver
* 1/2" flexible tubing bender
* 1/2' drill
* 1/4" drill
* 1/2" ID radiator elbow (Car Quest P/N 21784)
* 29" length of 1/2" OD soft copper tubing
* Two 1' hose clamps
* Clear Pill Bottle with tamper-proof lid
* One or two 8" cable ties
* A few inches of electricians tape

Proceed as follows:
Open up the engine hatch and locate the existing vent cap on the top of the trany under the chassis cross member. (See Figure 1). The vent cap is crimped loosely around the vent opening. Insert the '/2" open end wrench under the cap and pry it off. It is recommended that a flat bladed screwdriver not be used for this because of the tendency to damage the vent as it comes out of the trany.

Figure 1
Cut 3/8" off of one leg of the radiator tube elbow. This end of the elbow will go on the trany vent. Cut 5/8" off of the other leg.
Bend the 1/2" OD copper tubing into the approximate configuration shown in Figure 2.

Figure 2
Bend about 4" at 22 degrees from the trany end and about 6" at 90 degrees at the collector end. Keep all bends in the same plane.
Drill a 1/2' hole in the cap of the pill bottle. Do not remove the inner seal, but drill through that as well.
Drill a couple of 1/4" holes near the top of the pill bottle to permit venting.
Force the 6" end of the tube through the lid and wrap the end of this with the length of tape.
Place the pill bottle in its cap and the elbow on the other end of the tube. Clamp the elbow to the tube with the hose clamp. Install the other clamp loosely on the elbow being sure that the tightening screw will be accessible when the assembly is in place.
To install this assembly, carefully work the pill bottle behind the speedometer cable and the domestic water heater hoses. It should then be positioned just to the rear of the fender liner.
Force the elbow over the trany vent tightly against the trany housing. Clamp it.
Adjust the position of the tube and bottle so that the bottom of the bottle is visible when observed from the left front wheel area. (See Figure 3.)

Figure 3
Using the cable ties, secure the tube to the heater hoses. This system will carry trany fluid "burped" from trany over and away from the exhaust system and provide a visual indication of excess venting.

Remember: What you do to your coach is your responsibility. Nobody else is responsible!


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