lexforlife

iTrader: (7)

I have searched forums and really couldn't come up with final answer .. I'm in south Florida and I mean south so we are hot majority of the time .. I have been dying to remove the entire hcv assembly in the engine bay .

To those who have removed this ugly assembly , are you still able to adjust ac temp or does it just blow cold air but you are able to still control fan speed thru normal climate control options .. does the natural action of blend doors take care of blending heated water to be able to adjust ac temp from max cool to say 75 degrees..

As mentioned before , really don't care about loosing heat control itself ..

lexforlife

iTrader: (7)

Anyone who has removed the hcv , please report in if full ac control works

gerrb

iTrader: (34)

What's up Ed ? What are you up to now on your projects ?

I haven't removed that HCV in any of my SCs but this is what I believe happens if you do , that is why I never did and have no plans of doing so . The heater control valve lets the hot coolant used by the heater core to pass when there is the demand for a heater. Remember the blower blows air through that heater core that is why you get hot air . If you remove the HCV , then hot coolant always go through your heater core which means , yes your AC still will work but it won't be as cold. Why ? While you are trying to blow cold air with your blower , the heater core has hot coolant going through so cold and hot air kinda mixes out of the vent that is why ...

Another reason would be it will take longer for your engine to warm up. Remember what people do when an engine is kinda overheating ? They tell you to turn on your heater cause it circulates the coolant and cools it down while the blower is blowing through that heater core ?

Hey ... that is just my $0.02 . I maybe wrong though

lexforlife

iTrader: (7)

What's up broski. Just trying to further pretty up and simplify my engine bay. what I did yesterday was unplug the electrical connector going to valve setup making sure valve was fully open and drive with the ac on .. what I noticed is the auto climate control works , ac blows cold and only cold despite turning the temp up to say 78 degrees which would blend some heat into the ac output .. what climate control did was turn the fan down to its lowest setting the hotter I went and if I turned ac to say 68 degrees fan would turn higher and blow colder .. being in south Florida I think I can deal with this as I typically drive with windows down unless we are in the 90"s and high humidity or its raining .I.having this ugly assembly removed really cleans up engine bay

tonysc400

I would like a update on this , I want to remove this set up as well and just run the hoses to the firewall instead

LexIS007

iTrader: (1)

I can take a pic of mine today after work. I disconnected both coolant lines to the valve and got a $3 male-male composite fitting from AutoZone and connected the two coolant line together, bypassing the entire valve. Just be careful and make sure you don't put a kink in the coolant lines as it can cause pressure on other parts of the recirculating system and cause leaks other places. To prevent this, you may have to cut a bit off of one of the coolant lines to shorten the line to prevent the kink.

...and as far as I remember, AC works fine without the valve connected.

tonysc400

how was your heat? I notice your in Chicago and I know it can get cold there such as NYC does, my question is I will run new hoses "cut to fit" hoses , did you have the hose behind the head straight to the firewall and the other hose from the firewall to the water pipe which is located on the side of the pass side motor?

KahnBB6

iTrader: (5)

If you'd rather keep the original system working, I recommend replacing the plastic valve section with an Everco valve #74636:

https://www.clublexus.com/forums/per...ml#post8587609

But please disregard if removing the assembly regardless of function is your goal

tonysc400

i decided to keep the dam thing, lol

is there a heater hose part# I can use to replace the one coming from the firewall to the water pipe?

tonysc400

hey Kahn that is very helpful, this unit replaces the HCV if it goes bad?

KahnBB6

iTrader: (5)

I don't know which hose you're referring to but here are my part number notes for all the OEM hoses that go to the HCV and heater core connections.

87245-24290 — SC300 lower HCV coolant hose TO HEATER CORE
87245-24300 — SC300 TOP HCV coolant hose TO ENGINE (GE ONLY)
87251-24040 — SC300 heater core to LOWER hose (possibly still available through Lexus dealers only)
90467-22011 — Clamps for Heater Core to Block Hose 90467-22011 (x3)
16264-46010 (superseded to 16264-46041) — 2JZ-GE SC300 Water Bypass Hose No.2?? (VERIFY FOR SC300) + clamps (x2) 96135-51300
87245-24270 — Heater Core to Block Hose 2 (Lower) — DISCONTINUED (OR try 87245-24230?? Maybe not correct part)

Not the entire HCV. Your main assembly with the solenoid and VSV still has to be in working order. The Everco (or Four Seasons) #74636 just replaces the plastic valve assembly that gets the coolant hose connections. You have to carefully modify the Everco valve a little bit to allow it to clear and fit into your OEM HCV assembly because the Everco part has mounting parts on both sides whereas your OEM plastic valve only has mounting points on one side. You'll see in the pictures I posted in that thread. Also, you must re-use the old OEM valve's metal arm and bolt it onto the Everco in the same orientation. You can see that it looks like it's almost the exact same valve that operates in exactly the same orientation. You just have to shave the mounting point bracing on one side for it to fit correctly.

For me it worked very well for a couple of years. After that I noticed a slight leak in the plastic Everco valve and I managed to replace the whole assembly with a new OEM unit. But it still worked when I took it out. It could have been a fluke. I picked up another Everco valve to put with my original HCV assembly as an entire backup because everything else was still working, VSV and all.

In any case, if it ever has an issue in the future it is a $30-$40 plastic valve replacement (with just a bit of DIY with a Dremel and a screwdriver) that fits exactly like the OEM valve versus $200-$500+ for the full new HCV assembly.

tonysc400

thanks bro for the info , so by using this everco piece along with a oem HVC what would be the total you think

KahnBB6

iTrader: (5)

^^ The Everco (aka Four Seasons) #74636 heater control valve is about $40 from most common auto supply chains (Autozone, Pep Boys, Advance Auto, etc.). The rest of the cost is just your time and the use of a Dremel tool to *carefully* trim away mounting bracing on one side so that the rest of the Everco valve can cleanly mount in your OEM HCV assembly. And you have to swap the valve arm from your broken OEM plastic valve to the Everco.

$40 (give or take depending on the seller and shipping to you) and your own time to modify it slightly to fit on the one side for clearance and swap the arm. The factory mounting points, external shape, valve orientation and operation are all just like OEM. I don't know if I'd vouch that they are good for 20+ years of use like OEM but for the cost it worked for me and it fits, works and looks exactly like the OEM part once you bolt it into the main HCV assembly. Oh, and make sure your hoses are in good shape and use a new set of tension or screw clamps.

If I recall correctly Everco intended this as a direct replacement part for Sienna minivans or some other common Toyota. Toyota used the same exact valve design with less bracing on one side and a different rotator arm for the SC300/400/Soarer series.

And the mounting point and orientation arrow on the valve for the metal rotator arm is exactly the same as what you'll find on the OEM SC valve... which is why you can just swap your old arm right over.

After an SC forum member found a list of potential replacement Everco HCV valves I went through a process of buying and examining each and every one of them until I found that the #74636 model was the same as our OEM part physically and in function... other than the requirement to trim off the additional mounting material on one side (to make it look from 95% like OEM to 100% like OEM in order to fit in the HCV assembly bracket) and swapping over the OEM Lexus metal arm.

For picture references, refer to this thread from post #67 onward. My solution is among several that SC forum members have come up with over the years:

https://www.clublexus.com/forums/per...ml#post8587609

I will note, however, that as of this posting I tried looking up the 74636 valve and found it wasn't so easy to source at the moment. I found listings for them on ebay mostly but the major auto parts stores may have some trouble getting them due to low stock.

When I searched around for "2000 Toyota Sienna heater control valve" I came up with another possible replacement in part number 74646 which seems more readily available but I have done no testing or evaluation on it to verify that it operates 100% like our stock valve. It has the advantage of requiring no external modification however according to the pictures I saw. It is the valve opening and closing that would need to be verified once the OEM arm is swapped over. At the time of my posting this I cannot say with certainty that the 74646 valve functionally works just like the 74636 valve. But you can find it as cheap as $30 from some vendors.

I added this info to the end of O.L.T.'s thread which I linked above.

Ali SC3

iTrader: (10)

you could just put a manual valve on the line going into the core, open it in the winter, close it in the summer.. you don't need the whole vacuum setup. people have been doing that for decades.

LexIS007

iTrader: (1)

Here is what I did....no negative effects that I can tell with AC and/or heat.

Bypassed the HCV with a plastic barbed tube from AutoZone for $3 and works fine. Kept the HCV bolted for future use or will use the bracket for a boost controller.