2014 om651 factory AC diy repair

tech49

2019 2500 144 4cyl GAS
OK guys, Im going to attempt to repair the in-dash factory ac system myself. Found most of the parts on rockauto, but wondering if I should replace the high and low side pressure lines also?

My compressor did shred itself, with harsh grinding and compressor lube/oil flung all over the engine compartment, so Ive heard I need to flush the system after replacing parts. But I cant find any shop that will flush without doing the entire repair. Im wondering if I even need a flush, since Im already replacing most components, and just replace whatever parts are left?

Ordered:
compressor, drier, expansion valve, evap core, condenser.

Problem is - I cant seem to find the low and high side pressure hoses for sale anywhere. Is replacing them a pain due to connection points in the interior/cabin? Or should I simply clean out my existing hoses with a flush kit solvent like this - https://www.amazon.com/Goplus-Condi...8&qid=1527244825&sr=1-2&keywords=ac+flush+kit

Anyone done this before?
 
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Roger D

2016 Winnebago Navion 24J
I ran a collision/mechanical shop for 25 years and I repaired so many exploded compressor a/c systems that I can't even venture a guess as to how many. The number of times that I replaced a condenser and the lines I could count on one hand. Buy some flush and flush/blow out the condenser from both directions several times (3 or 4)..... done! There are no orifice tubes in the condenser. The high side line could have an orifice tube in it, but if it has an expansion valve it won't have an orifice tube, therefore flush and blow the lines....done!

The same holds true with the evaporator.... flush and blow. Flushing is mandatory. Replacing everything is not. Your greatest risk by not replacing everything will be a non-working a/c system that will require more flushing/blowing. The expansion valve has a very small transition hole from low side to high pressure, that is where the problem/blockage will be.

Mandatory will be compressor and drier. Measure the amount of oil to add and keep in mind that any extra oil will reduce the amount of freon the system will hold. Pump it down to 30 inches and run the vacuum pump for 30 minutes (minimum), and let it sit for 30 minutes. It should not drop in vacuum at all.

Fill and enjoy.
 

tech49

2019 2500 144 4cyl GAS
That info is appreciated, however with new condenser and evap cores going for nearly the cost of one can of flush, I went ahead and just bought them new. Cheap insurance. Plus, didnt want to spend a bunch of money on flush liquid only to find later I needed more....

Are Sprinters a tough AC job? The engine bay looks very accessible to me. I cant get anyone to call me back with a quote besides the dealer. I figure I have little to lose (with an already busted AC system) by trying it myself.

Does anyone know where to get MB specs regarding how much compressor oil to add vs 134a? One affects the other, as RogerD says above....
 
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tech49

2019 2500 144 4cyl GAS
Also, curious how many different styles of compressors there are on 4cyl sprinters? My clutch cover label says "7SBU17C"....different than the common "7SEU17C" Im seeing referred to in parts listings....that third letter change from E to B - is this important? I want to make sure I get the right compressor replacement, obviously.
 

Roger D

2016 Winnebago Navion 24J
Replacing the evaporator will probably require the complete removal of the dash. Most vehicles require it as well. I always try to avoid the evap if possible, because pulling the dash and reassembling it can result in unwanted squeaks and rattles. All the other stuff is pretty straight forward.
 

lindenengineering

Well-known member
The evap can be removed with the dash insitu
The challenge is getting the expansion valve "sandwich" of pipes and fittings into alignment. upon reassembly
I use a 90 x 5mm x.08 mm Allen bolt as a guide pin before entering the expansion valve proper to the assembly upon rebuild.

Yes I know as an old timer with 60 years in the business that once upon a time you could flush out the systems. However in today's newer systems the porting and and minute passages in evaps and condensers are so fine that any debris will not be dislodged by old fashioned methods. Indeed if enough flush liquid like "Frigiflush" use with nitrogen blast it CAN in some circumstances dwell trapped pockets of the flush liquid in the system causing oil dilution and premature failure of the compressor in service !

The latest directives in the industry are to simply replace the matrix's .
I follow that these days to avoid costly comebacks.
Dennis
 

tech49

2019 2500 144 4cyl GAS
****. So the evap core is a pain - Is it likely there is debris in the evap? Does that unit also have small porting and minute passages? Or were you referring more to the condenser unit?

Another told me the orifices in the expansion valve are too small to let much of anything through....would that kind of "protect" the evap core from debris circulation? I don't have the equipment for testing the pressure in the evaporation core, per the video, and holding pressure isn't my worry here. Too new of a vehicle. Im inclined to let the evap alone.

Calculated risk?
 

lindenengineering

Well-known member
****. So the evap core is a pain - Is it likely there is debris in the evap? Does that unit also have small porting and minute passages? Or were you referring more to the condenser unit?

Another told me the orifices in the expansion valve are too small to let much of anything through....would that kind of "protect" the evap core from debris circulation? I don't have the equipment for testing the pressure in the evaporation core, per the video, and holding pressure isn't my worry here. Too new of a vehicle. Im inclined to let the evap alone.

Calculated risk?
Yes
For those reasons I put a wire screen pressed into the inlet of the compressor .Traps any junk before ingestion.
https://www.autozone.com/cooling-he.../airsept-a-c-inline-filter-kit/933448_0_10460
Dennis
 
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Midwestdrifter

Engineer In Residence
A flush with pure alcohol (air brake antifreeze) and compressed air does a good job. I would think replacing the evap and cond is more trouble than its worth? Lots of other plastic things to break in the way...
 

tech49

2019 2500 144 4cyl GAS
Once I remove the air intake, and then the compressor, will I be able to start the engine and move the truck, or not at all? I ask because its already in the 90s here and to do this repair, Id like to get the van in some shade, but my only option with a roof ac unit is to pull it half inside - my garage doors are only 9ft high. But I don't want to leave the garage open to the elements should the repair take a few days.

That auto zone link says it doesn't fit my 2014 van - are those little screens universal fit?
 

lindenengineering

Well-known member
They work
Its basically the SAME unit as sold for about 1/3rd more through the tool trucks like Matco you see outside dealerships and Independent shops like mine.
If you buy one just make sure it has oil in it before use!

Now just a mention.
If you are thinking of using CANS of refrigerant from auto parts stores as a refrigerant medium --think again.

Caution. The amount of oil (usually PAG 100) is not specified within the contents.
Not only are you getting an undeclared amount of actual refrigerant these days due to revised EPA regs (since Jan 2018) but you will be filling it with a huge amount of unspecified oil; on top of what you have put into the new compressor.
The system is very sensitive to refrigerant amounts, hence an actual recycle /charge machine MUST be used to get it right and I would say a scale and a 30lb keg of R134a would be second best.
Dennis
 

tech49

2019 2500 144 4cyl GAS
Looking at parts, at the expansion valve, they are giving me two in the kit. But I dont think I need two - my truck is basic cargo, no rear or roof mounted AC. Just the in-dash is in my truck. I only need one, correct?
 

tech49

2019 2500 144 4cyl GAS
When buying parts, do cargo vans (without rear/roof mounted AC) need two expansion valves? Or just one?
 

tech49

2019 2500 144 4cyl GAS
Also - those little mesh screens - it says they're not compatible with my van - are they universal? If not, where do you get yours for sprinter vans?
 

lindenengineering

Well-known member
Its has ONE mounted behind the charge point manifold gauge point held together by two 5mm x 0,8 allen bolts.

Its says!!!--who's it?
I buy them in kits and come in multi sizes .
Dennis
 

tech49

2019 2500 144 4cyl GAS
Its says!!!--who's it?
I buy them in kits and come in multi sizes .
Dennis
I know, I know...the evil little brother to the infamous "they"......your prior link went to the advance auto parts website I believe, which identified my vehicle and a fitment issue. Those things are automated and sometimes not accurate...wanted to make sure.

Thanks for the clarifier on the exp valve.

Edit: I meant autozone website
 
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lindenengineering

Well-known member
Advance is not a good auto parts store for Pro stuff especially since they took over CarQuest and eliminated a lot of their Pro mechanics shop lines.

Good though, for selling that crap in a can they call PRO A/C charge which I have warned you about. Which incidentally really is can of oil !:rolleyes:
If you go on line and look for "compressor guards".
Wurth has kits:-
http://www.wurthusa.com/web/en/webs...oning/suctionscreenkits/suctionscreenkits.php

Dennis
 

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