AC Issues : Denso Compressor Pressure Not Correct (2 Viewers)

[jayfrem]

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Thanks a lot.

I will get you high pressure reading.

Should i go with a Toyota clutch or Aisin ?

Knew from a friend at Toyota we can get the silicone but i am ready for the proper fix once for all.

Againthe fan clutch pulls airflow from the raidiator to the engine ....

Is that clutch than strong to reach AC condenser and pull heat from it at low RPM?

Jay

 

[flintknapper]

Thanks a lot.

I will get you high pressure reading.

Should i go with a Toyota clutch or Aisin ?

Knew from a friend at Toyota we can get the silicone but i am ready for the proper fix once for all.

Againthe fan clutch pulls airflow from the raidiator to the engine ....

Is that clutch than strong to reach AC condenser and pull heat from it at low RPM?

Jay

Aisin will be fine. That is what most folks replace them with. If you live in a hot climate....some will modify the clutch by draining the old silicone fluid out and replacing with a heavier version (more shear). But if you aren't in an area that regularly sees 105° F then the stock unit for your vehicle should do fine.

The fan clutch is designed to start operating at a certain temperature (via a bimetal spring). It can run the fan (big plastic one behind your radiator) at anything from not engaged, to partially engaged, to fully engaged (as needed). There are times when the cooling demands of your engine, transmission and A/C are slight. During those conditions the fan clutch will allow the fan to either freewheel or just barely engage. It isn't needed...so no need to load the engine (fan drag). Conversely, when it's hot..the fan WILL engage (according to under-hood temperature) pulling/pushing air across/through the various components.

Since your A/T cooler, A/C condenser and radiator are all in front of the fan...it PULLS air through the fins of those items....helping to cool them down (they all release heat). Your Engine and Transmission are behind the fan...so the fan is PUSHING air across them...for the same purpose (to help cool them and evacuate air from under the hood).

As you can see... the Fan and Fan Clutch have to do a lot of work. So...replacing a really old fan clutch is just good maintenance IMO. The fan clutch is needed most at low rpm. I can't say for certain if it is the ONLY problem with your A/C...but its a fairly inexpensive way to insure you are getting proper air flow for ALL the components. The part itself usually runs about $100.00 (perhaps less if you shop around). This would let us eliminate it as a possible source of trouble while replacing a part that is almost certainly weak.

 

[jayfrem]

Aisin will be fine. That is what most folks replace them with. If you live in a hot climate....some will modify the clutch by draining the old silicone fluid out and replacing with a heavier version (more shear). But if you aren't in an area that regularly sees 105° F then the stock unit for your vehicle should do fine.

The fan clutch is designed to start operating at a certain temperature (via a bimetal spring). It can run the fan (big plastic one behind your radiator) at anything from not engaged, to partially engaged, to fully engaged (as needed). There are times when the cooling demands of your engine, transmission and A/C are slight. During those conditions the fan clutch will allow the fan to either freewheel or just barely engage. It isn't needed...so no need to load the engine (fan drag). Conversely, when it's hot..the fan WILL engage (according to under-hood temperature) pulling/pushing air across/through the various components.

Since your A/T cooler, A/C condenser and radiator are all in front of the fan...it PULLS air through the fins of those items....helping to cool them down (they all release heat). Your Engine and Transmission are behind the fan...so the fan is PUSHING air across them...for the same purpose (to help cool them and evacuate air from under the hood).

As you can see... the Fan and Fan Clutch have to do a lot of work. So...replacing a really old fan clutch is just good maintenance IMO. The fan clutch is needed most at low rpm. I can't say for certain if it is the ONLY problem with your A/C...but its a fairly inexpensive way to insure you are getting proper air flow for ALL the components. The part itself usually runs about $100.00 (perhaps less if you shop around). This would let us eliminate it as a possible source of trouble while replacing a part that is almost certainly weak.

Thanks a lot. Will do soon.

Seems Silicone fluid is available at Toyota .

Is it worth draining and putting new fluid ?

Our summers June- August do range from 85 F to 100 F daytime .

Jay

 

[nissanh]

Wonder anybody else came up with this:

Do you have a new radiator? Perhaps the fins are clogged with road girt/flies. When I bought mine and at the time I did my timing belt, I found lots of leafs, hay, and everything that you see on the road, trapped between the AC condenser and radiator, clogging many fins on the radiator. Altogether I can say about 1/3 of a regular sized plastic bag of stuff.

 

[flintknapper]

Seems Silicone fluid is available at Toyota .

I don't know what shear ratings they carry, but the silicone is available on Ebay, Amazon and other places.

ttps://www.ebay.com/itm/Team-Associated-ASC5456-Silicone-Differential-Diff-Fluid-Oil-20000-Weight-2-oz/162780461364?hash=item25e678b934%3Ag%3AaNgAAOSwDEtaH0HW&_sacat=0&_nkw=Team+Associated+ASC5456+Premium+Silicone+Diff+Fluid+20000cst&_from=R40&rt=nc&_trksid=m570.l1313

Is it worth draining and putting new fluid ?

I wouldn't do it...on a NEW fan clutch. You could remove and 'split' your old fan clutch and just exchange the fluid. Otherwise I'd wait and see how a new clutch does for you. I ran a new Blue Hub fan clutch on my 80 series for 3-4 years before I noticed a decrease in performance. I exchanged the fluid in it then with 20K CST and it really woke it up (about 48 ml). But it worked fine (from factory) before that.

Our summers June- August do range from 85 F to 100 F daytime .

Our Texas Summers are a bit hotter (and longer) than that....so I run modified fan clutches on both Cruisers, but I'm thinking you would be fine with a new replacement one (Aisin).

Jay

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[flintknapper]

Wonder anybody else came up with this:

Do you have a new radiator? Perhaps the fins are clogged with road girt/flies. When I bought mine and at the time I did my timing belt, I found lots of leafs, hay, and everything that you see on the road, trapped between the AC condenser and radiator, clogging many fins on the radiator. Altogether I can say about 1/3 of a regular sized plastic bag of stuff.

A dirty Condenser and Radiator will certainly contribute to poor engine and A/C cooling by blocking air flow.

So regular maintenance to clean those components is always a good idea. In my State (Texas) during certain times of the year...we have swarms of insects (Love-Bugs and gargantuan June-Bugs) that will clog a radiator if allowed to build up. But even normal road contaminants can collect over time.

The problem with trying to trouble-shoot someones A/C issues over the internet...is that so many factors are involved. This is especially true when you have a working unit but just need to fine tune it (get all out of it that you can).

 

[jayfrem]

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Fintknapper

No Aisin found yet.

I meant if i add new silicone to my existing fan clutch. This should do ?

Thank you

Jay

 

[flintknapper]

Fintknapper

No Aisin found yet.

I meant if i add new silicone to my existing fan clutch. This should do ?

Thank you

Jay

You can certainly remove your present fan clutch, open it (split it), drain the old fluid and replace with a higher 'shear' fluid. That is what most of us do (that require better cooling). You need to be careful not to damage or distort the O-Ring (seal), but otherwise it is not a difficult process. Make sure the bearing in your present fan clutch is still good though.

Use the search function to see the procedure.

 

[jayfrem]

You can certainly remove your present fan clutch, open it (split it), drain the old fluid and replace with a higher 'shear' fluid. That is what most of us do (that require better cooling). You need to be careful not to damage or distort the O-Ring (seal), but otherwise it is not a difficult process. Make sure the bearing in your present fan clutch is still good though.

Use the search function to see the procedure.

Here is the fluid avaiable on our part of the world.

 

[flintknapper]

OK, well if Toyota is your only source...that is fine.

I don't think they offer a CST over 10,000 though.

The one you have pictured is 3,000 CST (considered pretty light by most folks).

I wouldn't consider anything less than 10,000 CST if you want to see real improvements.

Toyota part numbers (I believe to be correct):

08816-03001 = 3,000 CST
08816-06001 = 6,000 CST
08816-10001 = 10,000 CST

 

[jayfrem]

OK, well if Toyota is your only source...that is fine.

I don't think they offer a CST over 10,000 though.

The one you have pictured is 3,000 CST (considered pretty light by most folks).

I wouldn't consider anything less than 10,000 CST if you want to see real improvements.

Toyota part numbers (I believe to be correct):

08816-03001 = 3,000 CST
08816-06001 = 6,000 CST
08816-10001 = 10,000 CST

Hi There

I changed the silicone fluid. Only think i found was 3000 CST.

I can now hear the fan more.

I did notice an AC improvement at idle ( in traffic) by approx 2 C .

Thank you guys for all the help.

It gets much colder when moving on the highway.

At idle i have an air temp of 11 C ( 51.8) for an ambient of 34 C (87.8).

I would like a but more colder air.

Should i consider:

- Changing to a 6000 CST fluid altough the ones at dealwr are only 3000 CST

- Changing my condenser . It has never been changed.

Pls advise.

Jay

 

[flintknapper]

If it were me...I would find (by whatever means) the 10K cst and put that in your fan clutch. I wouldn't replace the condenser...but a thorough cleaning of it might help. Also check to see that any of the foam strips that seal around the radiator and condenser are in place.

 

[jayfrem]

If it were me...I would find (by whatever means) the 10K cst and put that in your fan clutch. I wouldn't replace the condenser...but a thorough cleaning of it might help. Also check to see that any of the foam strips that seal around the radiator and condenser are in place.

Thanks a lot flintknapper for all the help.

At idle ( in traffic) what delta temp you are getting between ambiant and air temp ?

Thw condenser has been cleaned and its filter ( foam) changed.

Does Toyota offer the 10,000 CST ? Where to find it online ?

With 10 K CST will the fan be louder ?
With more viscous fluid the fan will engage faster and be workinf harder ?

Jay

 

[flintknapper]

At idle ( in traffic) what delta temp you are getting between ambiant and air temp ?

It will vary with the outside temperature (ambient). So...we aren't looking for a 'specific' number....that is a mistake folks often make. They think (erroneously) that their vent temps should always be 40-45° F. A good rule of thumb (for a properly working A/C system) at idle would be 30-40 degrees LESS than the ambient (outside) air temp. It should do slightly better with increased engine speed and air flow. So...if its 95° F. outside and you have 55° air at your vents (at idle) that is considered pretty darn good. Some will do better than that.

The condenser has been cleaned and its filter ( foam) changed.

Just to be clear...the 'condenser' is the heat exchanger at the front of the vehicle (in front of your radiator). It will not have a 'filter' but should have some type of foam like strips to help keep air from going around the condenser. Some folks confuse this with the evaporator (the other heat exchanger) that is housed inside the vehicle (behind the glove compartment) and it often does have a cabin filter. In any case..both need to be clean.

Does Toyota offer the 10,000 CST ? Where to find it online ?

Toyota does offer a 10K cst fluid. It is part # 08816-10001 (as I provided in an earlier post). If you have internet access and are not otherwise restricted from receiving items shipped to you, then any Toyota Dealer can order it for you. It doesn't have to be Toyota brand fluid. In fact...most of do not use the Toyota product. The 10K (or even higher cst) fluid can be ordered from Ebay, Amazon, etc....

With 10 K CST will the fan be louder ?

Slightly. But I don't find mine to objectionable and I run 20K cst in mine.

With more viscous fluid the fan will engage faster and be workinf harder ?

It will not engage faster, that is a function of the bimetal strip and how it is set. The fan clutch can also be adjusted 'timed' to start opening at a lesser or greater temperature depending on your needs.

The clutch with 10K cst fluid will work 'harder'....IF we understand 'harder' to mean 'with greater shear force' (less clutch slippage).

The fan will not begin to turn any sooner or run any longer with just a simple change of fluid (unless you overfill it). It WILL be more aggressive for the time it is engaged...because it won't be slipping as much. Less slipping means more air though the A/C condenser and Radiator. So better low speed cooling of both is the goal.

Jay

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[jayfrem]

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Flintknapper

Thank you for the reply.

Aligned on the delta temperature to look at and i get it. This is what i meant.

It is the condenser small radiator that has been cleaned.

Putting the 10,000 CST pushing the fan to work harder will tbis wear our the clutxh sooner ?

Will i a noticeable difference in AC cooling between 3000 CST and 10000 CST ?

I was only able to find the 10,000 CST off an e bay seller from Australia. Any other US stores for it ?

Jay