Dash Heat and Dash Air Conditioning Not Working

[dandick66]

Thanks for the detailed post.  This will certainly help me when the time comes to change my drier.  I’ve been doing some reading too, and I’m curious how you knew you had to add oil.  Some sites say you don’t need to add oil when you evacuate the system.  

[trailmug]

PAG oil will not be removed by evacuation, only flushing.. check out Sanden recommended oil quantities for each replaced component:

 

 

Edited September 30 by trailmug

[dandick66]

Ok. Thanks.  This makes more sense now.

[GringoScot]

Dandick66, while Trailmug is correct that "evacuation" will just boil off moisture in the lines and not oil, remember, I opened the system and REMOVED a device from the system, replacing it.  I do not have my chart and info on this PC, but as you can see in the chart that Trailmug references, there is an oil quantity listed for system components, specifically a receiver drier (and accumulator, condenser, minor system leak, other hoses/lines, etc.)  Therefore, I added oil in accordance to the chart that I had downloaded which listed motor coaches references based on length and hp.

[trailmug]

I'll also throw in there that Sanden uses "SP-15" which I believe is ISO 46, and can be somewhat less easy to find.

The stuff sucks up water and doesn't want to let it go.. officially, moisture-contaminated oil is supposed to be changed, but that has obvious limitations in practice. Minimize system empty / open time where possible.

Edited September 30 by trailmug

[GringoScot]

As a follow-up on this, I started the coach yesterday in 95F Southern Texas heat. 

The dash A/C registered 58-59F with my "turkey" thermometer. 

However, I did notice that not as much air was blowing out of the vents....SUBSTANTIALLY LESS compared to my Midwest trip back in July.

I opened the Genny bay and felt around the blower fan shroud/cover and noticed that the “spray on foam” between the cover and firewall had deteriorated.

Air was blowing out of this opening as well as half-way around the circumference of the fan shroud/cover (shown in RED in the attached images).

I could not feel the two cover clips…(broken off?  Vibrated off?)

I grabbed the Flex Tape and covered the gap.

To my amazement, the dash air is now blowing so much more than I ever recall.

I hope my misfortune may benefit the preventative maintenance of others.