OTR AC - My Bad

[Kevin Erion]

Jon,
Yes, that's the one. Thanks for the help.
Kevin

[Jon Wehrenberg]

My 99XL has a dual pane glass window with the sliding portion to the rear. There is moisture getting in-between the 2 pieces of glass, any easy fixes?
Kevin

I think I will have to get in line at the Prevost window store. My fixed side windows are fogging. They are glued in place. The last time I replaced one the adhesive was Sikaflex. Warm it up to make if flow easier. The windows are available from Prevost, but before I go buy one I am going to stick something in the sealer between panes like a basketball air nozzle, pull a vacuum on the window for a day or two, inject a little welding gas into it and try to reseal the perimeter. I have nothing to lose but a little time.

I'm going to do it after the POG, and I will photo and post everything. If it works I will write the procedure. From past experience this is a job replacing a glass that just takes a utility knife, patience and a tube of sikaflex.

[Jon Wehrenberg]

Jerry,

The manual says the brush length should be 3/4" or 19MM. To access the brush is a less than one minute job (for checking).

I am attaching a photo of the brush with the band clamp removed to the side.

On my 97 is a band clamp over the brushes and it is held in place with a pair of spring loaded clips. Pull a clip against spring tension and the "feet" of the clip will come out of the holes in the band and you can slide the clamp out of the way.

Lift the spring holding the brush in place and then slide the brush out.

As long as it is greater than 3/4" (19 MM) it is OK. The new length is 1 1/4" (32 MM).

The picture is of the condensing fan and the evaporator should be the same.

[mike kerley]

Jerry and Kevin,

Moisture in between glass layers is a common problem (so I've been told). I had my driver window changed by Prevost at a rally. Cost about $400 including labor.

they had several in stock on there truck and said they change them frequently. Had to do it, as I could not clearly see my mirror.

[Jon Wehrenberg]

Mike,

That moisture gets between all our windows because the seal has failed. I replaced one at Prevost once, and from that point on I did it myself for the very reason stated in your post. They are too expensive. If they failed on a 1987 coach, and then they failed on my 1997 coach there is nothing that can convince me the windows sold in 2006 are going to be any better.

By pulling a vacuum I hope to evaporate and remove the moisture, and by resealing the space between the two panes of glass and filling that space with dry (free of humidity) welding gas (I have argon, but nitrogen, helium or even a mix) there should be no more condensation until the seal is breached.

My rear TV camera had a glass cover and going from cold western NY down to FL was sure to form condensation which wouldn't go away so I made my own double pane glass and never had a condensation problem after that. I haven't tried it on the side windows yet, but I will and if successful as I pointed out earlier I will post the method.

[Jeffery Raymond]

On the curbside, you will find a box likely in a panel on the upper right hand side. Usually the middle solenoid is the first to go; there are little bimetal connections made inside of the silver solenoid, I think it is # 28. A good and simple test is to have someone run the OTR for a couple of seconds while you check the feed side amperage and then the output amperage. It should be putting about about 100 amps when the switch for the AC is on. If not, the fix is to simply replace the solenoid, about a 15 minute job.

Or you can go to a Prevost Car facility at about $2000/day and have them fix it.

[Just Plain Jeff]

You're not gonna like this, but the only proven fix to the whitening of the pilot and passenger window is to replace same. There was some geek who thought that he could drill a tiny hole and create a vacuum and remove the moisture and quickly reseal it, but I haven't seen anyone pull that one off yet.

As to the OTR, you will also find on the street side, center, a solenoid which controls the fans. That little bugger will go sometimes, which will kill the OTR air and make it seem that your motors are kerplunk. If the CB is good, the next place to look is the solenoid. Easy and quick fix: Take the old one out and put a new one in.

[Jon Wehrenberg]

Since the bus will be sitting for a while, this geek will eventually get around to pulling my fogged up door window and evacuating it, pushing a little argon in it, and attempting to reseal it.

If it works and lasts even half of the 7 to 10 years these things seem to last it will be worth it. The price Prevost wants you to pay for a product guaranteed to fail is absurd.