Dash AC

Reno55 With Dutch's picture I would try to find the smaller black line with the red stripe hose on the small canister up on the firewall. Then trace the other hose out of that small canister and see if you can determine where is goes. My guess is it will be somewhere in reach of the disconnected hose that you are dealing with.

Alternatively, the auto parts stores should have a roll of vacuum line for sale by the foot. I would buy like 10 feet and plug it into the small canister on the firewall and then around and through a side window and plug it into the line that you found. If the vents start working again then all you have to do is find a better way to route the longer hose into the cabin behind the dash or something.

Reno55 wrote:
Dutch 12078. That would be great, I presume that the F53 and the F550 is the same setup. I will look for that canister today. Thanks.

My apologies for the delay. Offline life got in the way... ;)

The photo below was taken from just in front of the right front tire. There are 3 vacuum lines in the plastic loom, one larger single hose and two smaller hoses that combine at the lower fitting. The part that rotted out on my coach was the short section that connects the larger hose to the canister on the right. The lower connector hose looked pretty weathered as well, so replaced both of them with short pieces of fuel hose. Pretty much any rubber hose should work, but the fuel line was on hand and should last a long time. The larger hose is the line from the engine to the canister, and the smaller red trace line is the feed to the small vacuum canister on the front of the firewall near the heater-A/C box. The other line on the small canister goes inside to the controls. The small white trace line I believe goes to a vacuum sensor that disables the A/C compressor on long hills when the vacuum drops too far.

I hope that helps!

Reno55 wrote:
Then I am mistaken. When I go to get filters for it, the parts houses state that their book sdo not show a F53 but they do show a F550.

Oreilly, Advance, NAPA and the rest of the large parts houses have listings in their computers for the F53. It's the noodle head behind the counter that needs to be up dated.

Richard

Then I am mistaken. When I go to get filters for it, the parts houses state that their book sdo not show a F53 but they do show a F550.

Where did the f550 come in to play. RV use the F53 number.

Dutch 12078. That would be great, I presume that the F53 and the F550 is the same setup. I will look for that canister today. Thanks.

That's the problem. I do not know where the line originates. The hose disappears to the right side under the dash. Only access to under the dash is at the insturment panel when I raise it up. No sign of the green line near the engine or in the front access panel. I will do some more probing. I have a trip planned next month down in the L.A. area next month and it will be hot driving down there.

The vacuum HVAC controls on our 2001 F53 quit a coupe of years ago, defaulting to just the defrosters as it should. I traced the failure to a rotted 2" long hose where the control hose runs to a 'Y' that connects to a vacuum canister located at the outside of the right hand frame rail just ahead of the front wheel. I cut a short section of spare fuel hose as a replacement and the controls are working properly now. I can take a picture of the location if you need it.

As stated you have a vacuum leak or the tank has crack. My tank is located passenger side in front of the front wheel. If bad get one bigger if possible . Doug fix works great also. Usually just need to new hoses and replace them all and it good for many years.

Your A/C unit defaults to defrost when there is no vacuum to the control. Find the inlet port on the control and work out from there. Check the loose hose when the engine is running to see if there is vacuum there. If so, there is your problem. Just find where to plug it in.