Evaporator Core advice - RESOLVED

All right, I need some advice.

My truck most likely has a busted evaporator core - however, it might not be the evaporator core, and just be the pressure switch or expansion valve. I had ordered a new evaporator (DENSO 4760030, OEM unavailable), but today I got a call letting me know it's not just on back order, it's completely out of stock, unknown when it'll be back in stock. Checked multiple online retailers. No dice.

I really want AC back before temperatures soar into the 90's here in the Carolinas - truck's already borderline to drive when it's over 70 out, especially with my commute being mostly highway.

The way I see it, I have 3 options.

1) Pull the evaporator core & associated stuff out, replace the parts I do have & refresh the O-rings on the Evap core, and hope for the best.

2) Hunt down a junkyard/part-out evaporator core, and pray whatever sent the vehicle to the junkyard + the trip to my house doesn't damage the core. I know it's not fine China, but it is definitely a "handle with care" part.

3) Go for a TYC, UAC, GPD, or 4 Seasons core - all 4 are in stock at RockAuto, but are cheap enough I'm nervous about fitment & quality.

Appreciate any advice you can give.

Any recommendations on the best option to pursue?

 

Why do you think it needs a new evaporator? Have you checked gas pressure in the system? Jumped the low pressure switch to see if it kicks on for a moment?

 

Had the AC charged a couple weeks back after replacing the compressor (seized), everything's gravy at the shop and then for the first 15-30 minutes of the drive home. Then a bunch of short hisses started from behind the glovebox, there was a weird smell, and the AC got steadily less powerful as I drove home. I hooked up a diagnostic manifold - absolute zero pressure with the engine running. Not no pressure difference, zero on both the high and low sides, so the R134 got pissed out. Triple checked that I had it hooked up correctly.

I also ran a UV light over every single component in the engine bay & front of the truck - not a bit of green glow except some dried coolant from a coolant leak I fixed in March. Leak needs to be inside the truck. Now, it could very well be the expansion valve, evap switch, or a O-ring, but there's really only one major component left it can be.

 

With zero pressure and a hiss in the glovebox, it certainly seems like a probable evaporator core. I, personally, wouldn’t hesitate to use an aftermarket brand. But that’s just me.

@Dm93 - any input?

 

Really, instead of buying an aftermarket new part you would potentially go without A/C because a pure toyota part is not available. My opinion is buy the new aftermarket part and enjoy your A/C and don't scrounge around in a salvage yard. It's not a lower ball joint.

 

Use the UV light down by the evap drain tube and see if there's any green alien blood coming out of it

 

Does R134 automatically have UV dye in it? I though you had to add a can to get it to show up.

 

I am, in fact, asking because I would prefer buying an aftermarket part to not having AC, I just would rather not put a part in that's 50/50 if it's going to work for the long run - I don't know the aftermarket brands that are available well enough to know if there's a meaningful difference between them, or if there are any that I need to stay far away from.

Only spot in the engine bay with any glow.

You do. The shop I went to adds UV dye to the refrigerant when they do a charge.

 

I replaced my evaporator recently with one from NAPA, easy job.

 

What part number do you have for the evap core? Is it 8850104030 ? A quick search yielded those to be available. They may be backordered but I don't see the dreaded "Discontinued" status on them from a handful of online dealers I checked on.

You mentioned TYC, and if you're in a pinch, TYC makes them: TYC 97121 Have had pretty good results substituting OEM with TYC on two of my Hondas.

 

1st gen evaporators are relatively easy to change unlike 2nd and 3rd gens where the whole dash has to come out so I wouldn't be too afraid of an aftermarket one.

 

I'd go for an aftermarket evap core. Should arrive pressurized (well, vaccuumed) so you know it's good.

Pretty simple process, outlined in this step-by-step guide with pictures of all the parts and tools needed. Swap out the pressure switch and expansion valve while you're in there.

Replacing the A/C Evaporator Core on a 1st gen Tacoma – AdventureTaco

 

OEM is also a $300 part... and I would really rather not spend an extra $200 on a Toyota emblem. I'm thinking of going for either the TYC or UAC, since those are in the $40-50 range.

Thankfully the DENSO part is not discontinued, just Out Of Stock.

@turbodb , that's the plan. Appreciate the advice, everyone. I've made my call.

 

Toyota probably doesn’t make their own A/C cores.

 

Pretty much no automotive manufacturer makes their own parts, they have a list of dimensions and specifications a part needs to meet or exceed, they typically then have 3rd party manufacturers bid on making those parts, and winning manufacturer gets the contract.
Im sure there's more to it than that but that's the basics of it for OEM parts.

 

I mean, sure, sort of.

Once Toyota contracts a manufacturer and puts their name on a part or puts the part in a Toyota bag, you can be sure it's high quality. That's not true for all aftermarket brands, since there's no requirement that a brand actually go through Toyota QC in order to sell (for instance) and aftermarket A/C Evap Core.

So I totally get where OP is coming from; it's part of the reason we all look to Denso, Aisin, Koyo, etc. for quality parts - because we know that Toyota looks to them for the same.

 

All true, I was just pointing out that some people assume that if a part is in a Toyota (or pick your brand) box that they manufactured it, this is often far from the case when it comes to OEMs and even some aftermarket stuff.