Rear Evap Core Removal

[obe12]

I see the 4 Seasons Parts Rear Eval and Expansion Valve. I have a couple of questions....

The electrical device on the side of the rear expansion valve, is that a solenoid shut off or control flow regulating device? How the fit of the 4seasons Parts?


I have 381K miles and my LC developed engine oil leak, Front O ring around the oil pump and rear O ring behind rear main oil seal retainer plate. I pulled the engine to repair these leaks, decided to replace Alternator, Starter, AC compressor, all the heater hoses, by pass hoses and radiator hoses along with a new radiator while the engine was removed. I changed the front trans converter input seal, cam - crank seals, oil pump, tensioners, t belt and drive belt. I did replace the Condenser removable filter / moister absorbent bag. I evacuated and recharged the system and really hot day the front system would get warm and then get cold, pressures would both rise and both fall together and compressor would not cycle. The rear unit with front unit low blower, would stay steady pressures. 1/4 pound more freon and the system stabilized and stopped having pressures rise and fall when front blower is on hi. I was feeling it was a bad expansion valve in the front at first.

My manual says removal of Dash is required to remove front Evap / Expansion Valve Unit. I purchased a front Evap. Expansion Valve, Rear Eval core, rear Expansion Valve 4 Seasons. I on the fence to send the parts back, or if they are correct parts keep them for when I have to break the system open. So far, it's steady cold when 104 degrees outside, cold front and rear. When I removed the glove box, I see a dash part that crosses the evaporator it's not removable unless I cut it out and adapt it to be bolted back in blocking the removal of the EVAP core. I was able to remove the cover of the evap core to clean the evap core and case.

Has anyone modified this crossing dash part that the glove box attaches too to allow removal of the Evap core without having to remove the dash!

 

[familywagon]

I see the 4 Seasons Parts Rear Eval and Expansion Valve. I have a couple of questions....

The electrical device on the side of the rear expansion valve, is that a solenoid shut off or control flow regulating device? How the fit of the 4seasons Parts?


I have 381K miles and my LC developed engine oil leak, Front O ring around the oil pump and rear O ring behind rear main oil seal retainer plate. I pulled the engine to repair these leaks, decided to replace Alternator, Starter, AC compressor, all the heater hoses, by pass hoses and radiator hoses along with a new radiator while the engine was removed. I changed the front trans converter input seal, cam - crank seals, oil pump, tensioners, t belt and drive belt. I did replace the Condenser removable filter / moister absorbent bag. I evacuated and recharged the system and really hot day the front system would get warm and then get cold, pressures would both rise and both fall together and compressor would not cycle. The rear unit with front unit low blower, would stay steady pressures. 1/4 pound more freon and the system stabilized and stopped having pressures rise and fall when front blower is on hi. I was feeling it was a bad expansion valve in the front at first.

My manual says removal of Dash is required to remove front Evap / Expansion Valve Unit. I purchased a front Evap. Expansion Valve, Rear Eval core, rear Expansion Valve 4 Seasons. I on the fence to send the parts back, or if they are correct parts keep them for when I have to break the system open. So far, it's steady cold when 104 degrees outside, cold front and rear. When I removed the glove box, I see a dash part that crosses the evaporator it's not removable unless I cut it out and adapt it to be bolted back in blocking the removal of the EVAP core. I was able to remove the cover of the evap core to clean the evap core and case.

Has anyone modified this crossing dash part that the glove box attaches too to allow removal of the Evap core without having to remove the dash!

The electrical device on the side of the rear expansion valve, is that a solenoid shut off or control flow regulating device? How the fit of the 4seasons Parts?
Exactly, that was the piece that was not working on the unit from my first attempt. The one I bought originally did not come with the electrical device so I removed the old one and added it. I guess I damaged it in the process because when I went back in the electric device was not engaging. (you can check it with a 9 volt battery)

Has anyone modified this crossing dash part that the glove box attaches too to allow removal of the Evap core without having to remove the dash!
Oh yeah that's right you have to cut the dash part! There's a thread on here that does into detail, I did cut. I also bought this part from fellow Ih8mud user

I mean if it's cycling cold and warm it's because the pressure is not regulating in the system. There's only three moving parts ( Compressor, and the two expansion valves) in the systems so it's pretty easy to diagnose and even easier to just replace all the parts.

The expansion valve for the rear I linked above came with the electrical device and it was just plug and play.

 

[obe12]

The electrical device on the side of the rear expansion valve, is that a solenoid shut off or control flow regulating device? How the fit of the 4seasons Parts?
Exactly, that was the piece that was not working on the unit from my first attempt. The one I bought originally did not come with the electrical device so I removed the old one and added it. I guess I damaged it in the process because when I went back in the electric device was not engaging. (you can check it with a 9 volt battery)

Has anyone modified this crossing dash part that the glove box attaches too to allow removal of the Evap core without having to remove the dash!
Oh yeah that's right you have to cut the dash part! There's a thread on here that does into detail, I did cut. I also bought this part from fellow Ih8mud user

I mean if it's cycling cold and warm it's because the pressure is not regulating in the system. There's only three moving parts ( Compressor, and the two expansion valves) in the systems so it's pretty easy to diagnose and even easier to just replace all the parts.

The expansion valve for the rear I linked above came with the electrical device and it was just plug and play.

Oh thank you...for the reply....

It appeared the rear by logic was a flow control solenoid Off / On. when I shut my rear unit off and unload the evap heating Blower Low my pressures would stabilize and ambient temp 98 it would only pull down IDLE now, to 42-45 PSI low. Fan in front of radiator, 1500-2000 RPM pull down to 35 ish and cool good. Now load the evap with heat, Hi blower same outside conditions pressures would rise and fall together, rise about 50 psi and loose cooling, drop under 40 cool again. H block Expansion valves control Super Heat an AC temp, liquid level of refrigerant in EVAP. It sure was acting like a bad expansion valve in front. I added 1/4 pound and pressures normalized... stayed steady no when Loading the Evap with heat, Front or Rear unit on doesn't matter. Front fan comes on just over 250 PSI and cools pretty good now. That little freon level change and expansion valve like it. I preordered all the parts in and saw the glove box thing. I been driving it in Texas heat daily now 95-105 degrees and no trouble so far. Not like my Lexus IS car Electric fans, and freeze you out on 100 degree day idling. but not bad ...

 

[Lavender Jones]

Wow this is the thread i have been looking for. I have been hearing fluid sloshing around towards the rear end and was advised that the likely culprit is the rear AC evap drain being clogged. thanks to the pics and info in this thread i know what i am looking for now. commenting so i can come back to this thread later

 

[rslimbers]

great info. I see a lot of solutions but am wondering about diagnosis

My system has been blowing cold for a while. I definitely have a leak but if have no idea if I am having issues at my front or rear evap.

I’m at 215k and plan to have this thing for eternity. Should I just go ahead and replace both? Any thing else I can/should do to get this ac system refreshed for the long haul?

 

[obe12]

great info. I see a lot of solutions but am wondering about diagnosis

My system has been blowing cold for a while. I definitely have a leak but if have no idea if I am having issues at my front or rear evap.

I’m at 215k and plan to have this thing for eternity. Should I just go ahead and replace both? Any thing else I can/should do to get this ac system refreshed for the long haul

Well I chose to do both evap cores, compressor, new espansion valves and condenser with drier with discharge line / hose over fan shroud.



Why , at 379000 1999 just a matter of time.

With new Compressor Denso having the correct oil can’t remember the amount needed for both evaps, condenser, and with drier took. But Black Death you don’t want. Low Freon happens and compressor pump oil into rear evap core and starves compressor oil balance. Compressor overheats and starts coming apart internally and contaminates the condenser. Here we go… nearly impossible to clean the condenser at that point

So I would remove compressor and drain the oil and evaluate the condition of your system 1st. Any black oil now I change the compressor , condenser , evap cores and espansion valves. Change the discharge line because that are a notorious leak spot.

If you old compressor oil is clean, measure it

Needs 1-3 oz in it of that oil balance it correct

Change each evap core adding 1.6 oz per core
Change desiccant bag in condenser and recharge.

Evacuation is so critical… here for a long lasting system.

Pulling 29.9… inches vacume was a standard for years and I did it that way since 1982. However commercial Ac systems we pull Microns a finer unit of measurement than inches of mercury. Once below 500 microns and maintain it for deca test your are ready for a charge of Freon.

Pulling under 500 microns boils all the moister out of your ac system. At 29.9… inches would be 1500-1000 microns and not a real deep vacuum to rid the system of moister.

I maintained under 500 microns for 5 hrs in mine. Took me 6 hrs to get under 500 microns.

At the end my system is cold and works perfectly

A lot of info here …

Fan clutch can cause hi head pressures in the summer and help shorten life of the compressor too. Make sure it’s good.

Pulling the compressor is a …itch but checking oil balance is critical and if it’s contaminated.

A leak and running it a while that way, will pool the oil in the evaporators … and compressor will have less that 1 oz in it and possible black too. Not good.

Not enough liquid flow to help circulate the oil back to the compressor. Why when low it pools the oil in the evaporators

Have fun

 

[rslimbers]

Well I chose to do both evap cores, compressor, new espansion valves and condenser with drier with discharge line / hose over fan shroud.



Why , at 379000 1999 just a matter of time.

With new Compressor Denso having the correct oil can’t remember the amount needed for both evaps, condenser, and with drier took. But Black Death you don’t want. Low Freon happens and compressor pump oil into rear evap core and starves compressor oil balance. Compressor overheats and starts coming apart internally and contaminates the condenser. Here we go… nearly impossible to clean the condenser at that point

So I would remove compressor and drain the oil and evaluate the condition of your system 1st. Any black oil now I change the compressor , condenser , evap cores and espansion valves. Change the discharge line because that are a notorious leak spot.

If you old compressor oil is clean, measure it

Needs 1-3 oz in it of that oil balance it correct

Change each evap core adding 1.6 oz per core
Change desiccant bag in condenser and recharge.

Evacuation is so critical… here for a long lasting system.

Pulling 29.9… inches vacume was a standard for years and I did it that way since 1982. However commercial Ac systems we pull Microns a finer unit of measurement than inches of mercury. Once below 500 microns and maintain it for deca test your are ready for a charge of Freon.

Pulling under 500 microns boils all the moister out of your ac system. At 29.9… inches would be 1500-1000 microns and not a real deep vacuum to rid the system of moister.

I maintained under 500 microns for 5 hrs in mine. Took me 6 hrs to get under 500 microns.

At the end my system is cold and works perfectly

A lot of info here …

Fan clutch can cause hi head pressures in the summer and help shorten life of the compressor too. Make sure it’s good.

Pulling the compressor is a …itch but checking oil balance is critical and if it’s contaminated.

A leak and running it a while that way, will pool the oil in the evaporators … and compressor will have less that 1 oz in it and possible black too. Not good.

Not enough liquid flow to help circulate the oil back to the compressor. Why when low it pools the oil in the evaporators

Have fun

After doing my timing belt less than a year ago, the 1 word I was hoping not to hear in response my post was… compressor! Thanks though awesome info

 

[obe12]

After doing my timing belt less than a year ago, the 1 word I was hoping not to hear in response my post was… compressor! Thanks though awesome info

Yes they are a bear… however through the opening of the tie rod end rack and pinion you can use long extension universal 14 mm 3/8 drive to loosen the back bolt without removal of oil filter adapter .

Oil balance is essential to long term reliability… draining the oil in old compressor allows you to check condition of the oil and amount.

Yes it’s a pain!

Tex