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 > Locating a/c expansion valve

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Ready2BRetired

Texas

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Posted: 05/19/19 05:54pm Link  |  Quote  |  Print  |  Notify Moderator

I have a 2005 Tiffin Allegro Open Road on a W 22 chassis.I am replacing a/c compressor,dryer and hopefully expansion valve. First two have been pretty straight-forward. Need to locate the expansion valve. Anyone been down this road as to location,accessibility etc. Any info is appreciated.

K Charles

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Posted: 05/19/19 06:06pm Link  |  Quote  |  Print  |  Notify Moderator

It has to be at the inlet to the evaporator because that is where the cold begins.





MountainAir05

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Posted: 05/19/19 06:06pm Link  |  Quote  |  Print  |  Notify Moderator

Follow the two lines to the box on the LH side over the passenger wheel. The 1.5 x 3.5 x 1 inch block is it. Type in vehicle ac expansion valve in google and you will get pictures.

sch911

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Posted: 05/19/19 06:27pm Link  |  Quote  |  Print  |  Notify Moderator

It's up front generally accessible under the hood passenger side, along wit the charge ports.


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Ready2BRetired

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Posted: 05/19/19 06:57pm Link  |  Quote  |  Print  |  Notify Moderator

Thx for the replies. I thought too initially that's where it should be. No luck there, the two lines run into the plastic housing no valve in
sight. Possible access from inside under dash?

DFord

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Posted: 05/19/19 09:55pm Link  |  Quote  |  Print  |  Notify Moderator

Do you have any idea what you're doing? Can you tell the liquid line from the suction line? The expansion valve will be at the end of the liquid line just before the evaporator. There should a sensor bulb connected to the outlet of the evaporator connected to the expansion valve. After you've replaced all these pieces, be sure to evacuate the system with a good vacuum pump before putting any refrigerant back into the system. Failure to do that will cause an early failure of the system - pulling a vacuum is not an optional step. Every MH a/c system I've ever seen has a sightglass in the liquid line. Recharge the refrigerant till the bubbles/foam passing the glass clears up and stop there.


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dougrainer

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Posted: 05/20/19 05:31am Link  |  Quote  |  Print  |  Notify Moderator

DFord wrote:

Do you have any idea what you're doing? Can you tell the liquid line from the suction line? The expansion valve will be at the end of the liquid line just before the evaporator. There should a sensor bulb connected to the outlet of the evaporator connected to the expansion valve. After you've replaced all these pieces, be sure to evacuate the system with a good vacuum pump before putting any refrigerant back into the system. Failure to do that will cause an early failure of the system - pulling a vacuum is not an optional step. Every MH a/c system I've ever seen has a sightglass in the liquid line. Recharge the refrigerant till the bubbles/foam passing the glass clears up and stop there.


Sorry, I have to ask. Do YOU know what you are doing?[emoticon] Unlike Freon 12, with 134a the SIGHT GLASS will always have bubbles with a full charge. Trying to charge until bubbles are GONE will result in an overcharged system and overcharged will NOT cool at all. The OP should have a Denso AC system. THAT type system has the expansion valve INSIDE the dash in the Denso unit. Kind of a pain to get too on a Tiffin unit. Doug

dougrainer

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Posted: 05/20/19 05:31am Link  |  Quote  |  Print  |  Notify Moderator

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Ready2BRetired

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Posted: 05/20/19 08:28am Link  |  Quote  |  Print  |  Notify Moderator

Thx again for the replies. Doug you are corrrct, it is a Denso system and I have since learned the whole box w/ evap etc has to come out from the inside.Have to figure out how the lower dash kick panels all come out.Anyone familiar w/ a competent shop in the East Texas area that might be reasonable?

wa8yxm

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Posted: 05/20/19 04:40pm Link  |  Quote  |  Print  |  Notify Moderator

Well. this is something I've said before
I replaced the heater core on a 70's era Olds and Ford.
(Clamp hoses, disconnect, pull about a dozen screws. Life cover, pad, core,, Get core rebuilt, replace in reverse order, Top off cooling system)

Today..
Evacuate ac system, disconnect lines at firewall and cap off

Disassemble passenger side dash.
Slide A/C Evaporator out on its rails
Life core out from behind it (After clamping and disconnecting hoses)

What use to be 15 minutes is now an hour and a half.


Ford AC system. Could be completely removed STILL SEALED from under the hood.. Was a bit tricky to do it sealed. but it could be done. Today... See above


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