??? DIY Recharge of Dash Air

skigramp · 05-10-2007, 12:26 PM

About once a year my dash air decides to quit "chilling" ... I take the rig to the Freightliner shop ... they evacuate the system, add some dye, charge the system, let the engine run for awhile ... find no leaks ... all of this at $100 an hour ...

Question: Do any of you go to your favorite automotive supply store, buy a can of the correct refrigerant and then <span class="ev_code_RED">add enough refrigerant (as a DIY project) to get your dash air working again?</span>

skigramp · 05-10-2007, 12:26 PM

About once a year my dash air decides to quit "chilling" ... I take the rig to the Freightliner shop ... they evacuate the system, add some dye, charge the system, let the engine run for awhile ... find no leaks ... all of this at $100 an hour ...

Question: Do any of you go to your favorite automotive supply store, buy a can of the correct refrigerant and then <span class="ev_code_RED">add enough refrigerant (as a DIY project) to get your dash air working again?</span>

CC38EL · 05-10-2007, 12:59 PM

SkiGramp....

Don't know what kind of rig you have, but a gentleman on another newsgroup sent me a DIY process that might work for you. I have the same problem....seems like I have to do this every time I change the oil.

If you would like, I'll send this to you in an email.

Roadking · 05-10-2007, 02:06 PM

A couple years ago my AC was only cooling to about 65 degrees as measured at the air ducts. I went to the local parts store and bought the recharge system with the pressure gauge, so if I need to add refridgerent again I all I need is the R-134 canister. The kit was about $30 bucks. Adding one cylinder kept the pressure within the green limits on the gauge and the air temp is now in the 45 degree range. Very simple to do. I know I have a very slow leak on the accumlator/dryer fittings so I carry a spare can of R134 with me just in case I need it. If I need to add another can I will also add the small can of oil/lubricant the parts stores sell for R134 systems. IF you need to add a can every oil change then you clearly have a fairly substantial leak.

DonavonP · 05-10-2007, 02:43 PM

When I had my DP Freightliner Chassis, I would have to add a can each year. There was about 70 feet of refrigerant line on the DP so I guess a little seepage is expected.

I bought a kit with a cheap gauge and it worked fine. I couldn't tell the difference between my adding a can with a $10 gauge and the dealer adding a can with $2000.00 worth of gauges and sniffers etc. The AC on the 97
Discovery was poor either way but better than nothing.

It's an easy job but wear safety glasses. A shot of 134A in the eye is permanent blindness.

John_Canfield · 05-10-2007, 05:40 PM

The way I have always done it is to add gas until the suction line at the compressor gets real cold and starts condensing moisture.

RLS · 05-11-2007, 03:56 AM

ua40j
I would like a copy of the DIY process.
Thank you.

skigramp · 05-11-2007, 08:13 AM

Thanks for all the good responses ... once again this bulletin board has given me the amount and kinds of information that I wanted ...

Out of curiosity ... I measured the temperatures of the cabin and the temperature of the dash air duct this morning (after yesterday's recharge) ...

Dash Air on MAX
Cabin Temp 65
Output duct 46

So I am getting an 18 or 19 degree difference in air temps between the air going in and the air coming out when the system is fully charged.

Is this consistent with what you guys get?

JnGOnTheGo · 05-11-2007, 08:22 AM

ua40J, Please email me a copy of the DIY process.

Thanks,

John_Canfield · 05-11-2007, 09:38 AM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by skigramp:
--snip--
Out of curiosity ... I measured the temperatures of the cabin and the temperature of the dash air duct this morning (after yesterday's recharge) ...

Dash Air on MAX
Cabin Temp 65
Output duct 46

So I am getting an 18 or 19 degree difference in air temps between the air going in and the air coming out when the system is fully charged.

Is this consistent with what you guys get? </div></BLOCKQUOTE>20 degree differential is about right but again I think a great 'seat of the pants' test is to feel the suction line at the compressor. It should be very cold to the touch and condensing moisture.

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">ua40J, Please email me a copy of the DIY process. </div></BLOCKQUOTE>Jim - a recharge kit in an auto parts store undoubtedly has complete instructions on the kit. The charge process will be different if you have a gauge set or a direct hose from the freon can to the suction side service fitting.

CC38EL · 05-11-2007, 10:47 AM

John, I agree with you on the instructions on the kits at auto parts stores. But what I was looking for was information on what to look for on a diesel engine/chassis setup.

I can figure it out when I lift the lid on my VW, but the coach is setup differently. Plus I wanted to make sure the fitting were the same.

Web searching for servicing A/Cs on diesels lists some very complicated processes. Almost to the point that if I was driving a semi, and my A/C went out, I'd live without it.

Jim B gave me some good pointers on what to look for in a RV A/C job.

That combined with info on the recharge kits should get me through.

RLS you don't show an email address, so I sent you a private message.

Regards,

CC38EL · 05-19-2007, 08:50 AM

Well, made the attempt to recharge my dash air conditioning today. Because it was on sale, I purchased a refill kit with a gauge. Good thing I did. The system was reading slightly overcharged.

I confirmed this by putting the gauge and refill kit on my car and was true.

So...if you decide to DIY on the recharge, I highly recommend a $19 gauge and refill can from Wally World.

Now....anybody got any ideas why my A/C won't cool? Fans on radiator don't turn on either when in Max A/C. Can't tell if the compressor is cycling or not.

RKL2 · 05-19-2007, 12:02 PM

If the fans are not starting, it is probably a bad condensor control relay....Without the condensor fans running, the condensor will not operate correctly and it will not cool....Find the relay, jump it to start fans and look to see if system makes cold air....if so, replace relay....RKL

RLS · 05-20-2007, 05:08 AM

RKL,
I have the same problem of no fans. Do you know where I mignt find the fan relay, or a good place to start looking?

RKL2 · 05-20-2007, 05:50 AM

RLS....I believe it is upfront under the hood. It must sense pressure in the system and that probably is in the plumbing to the left of the hood openning...I would call customer service at Winnebago and ask one of the tech reps and also ask for the part number...
I believe it is round and scwews into the system,,It should have 2 electrical tabs on top...Also, a auto AC shop should be able to tell you what it looks like and where it should be....If you find out, please post.....Sorry I coud not be of further help....RKL

TXiceman · 05-20-2007, 10:55 AM

ua40J, if it is not cooling properly, you can not make an assessment of being overcharged using only the suction gauge supplied with the R-134a can. I would recommend that you take it tto a qualified technician and get it checked properly.

Ken

RLS · 05-20-2007, 05:54 PM

RKL, Thank you for the info. I will give it a look see as soon as I can and see what I can find out.

CC38EL · 05-21-2007, 02:10 AM

Looking at the a/c and heater setup above the generator, I found 2 circular objects that could be relays or sensors. One is on the 'high' pressure line, one on the low pressure line.

The smaller of the 2, the one on the high pressure line was easy to get to. I jumpered around it, but no joy on the fans.

The larger of the 2, on the low pressure line is more difficult. Winnebago did not want that connection to come off. It's tie wrapped and taped. I don't have a good jumper for it yet, but will have by this weekend.

None of the schematics on this site reference those 2 devices. So I'll be calling Winnebago today to find out. The SCS/Frigette website was not much help.

Thanks to all for the assistance and advice.

CC38EL · 05-22-2007, 02:06 AM

My call to Customer Relations (spoke with Troy) was not as successful as I had hoped. No location information for the condensor control relay.

Troy did offer help with a fan control relay in my left electronics bay (forward block, bottom row). I'll check that out tonight.

Emailing SCS/Frigette about location of the relays. Will update as I get information.

RKL2 · 05-22-2007, 07:36 AM

ua40j...Why not call tech services at SCS Fridgette....they were helpful to me once on a heater core issue....RKL