AC hard lines

[eurasiaoverland]

Hi guys

Back when I bought my 3rd Gen, I stripped the truck to do an engine rebuild. I took out all the AC parts except the evaporator / expansion valve, and never wanted to put them back in - until now.

When I undid one of the joints between two hard lines, it was damn tight and the threads stripped, so I need new ones.

I can get them new, but they are not cheap. I spoke to someone parting out a vehicle and he told me that the joint is sealed, and so he does not want to open it to check.

Makes sense (and the ebay seller has good feedback), but I just wanted to know if anyone else had this problem with the threads on AC pipes stripping.

My feeling is that the threads stripped because there was galvanic corrosion between the aluminium pipe and the steel union nut, and that there is no sealing compound. There is an O-ring to make the seal.

Thanks

EO

 

[JRZEE2000TR4LTD]

Hi guys

Back when I bought my 3rd Gen, I stripped the truck to do an engine rebuild. I took out all the AC parts except the evaporator / expansion valve, and never wanted to put them back in - until now.

When I undid one of the joints between two hard lines, it was damn tight and the threads stripped, so I need new ones.

I can get them new, but they are not cheap. I spoke to someone parting out a vehicle and he told me that the joint is sealed, and so he does not want to open it to check.

Makes sense (and the ebay seller has good feedback), but I just wanted to know if anyone else had this problem with the threads on AC pipes stripping.

My feeling is that the threads stripped because there was galvanic corrosion between the aluminium pipe and the steel union nut, and that there is no sealing compound. There is an O-ring to make the seal.

Thanks

EO

Which line are you talking about? The one that goes from the drier to the expansion valve (then the evaporator) or the one that goes from the drier to the condensor (actually flow is the other way but you get what I mean)? Not sure where there is a connection "between two hard pipes" unless your Hilux is different.

 

[eurasiaoverland]

Indeed mine is different to yours as its RHD. There are two low-pressure lines; one runs from the evaporator to near the front left headlight, then there's a joint (the one that was bad on mine) and the pipe goes across the front of the vehicle, in front of the condenser, and to the flexible suction hose on the pump.

 

[JRZEE2000TR4LTD]

Indeed mine is different to yours as its RHD. There are two low-pressure lines; one runs from the evaporator to near the front left headlight, then there's a joint (the one that was bad on mine) and the pipe goes across the front of the vehicle, in front of the condenser, and to the flexible suction hose on the pump.

Any of this look familiar?

TOYOTA HILUXLN67R-MDN - ELECTRICAL - HEATING AIR CONDITIONING COOLER PIPING | Japan Parts EU

 

[eurasiaoverland]

Thanks for the link.

Perhaps it was not clear, but I am asking if anyone had the experience of stripping threads on the hard AC pipes, and whether they are bonded with sealant. But I see now that the US 4Runner has hard line connections only at the firewall, which is far less exposed and prone to corrosion, so maybe my question is not a good one

Here is my circuit: TOYOTA HILUX SURFRZN185W-GAMXK - ELECTRICAL - HEATING AIR CONDITIONING COOLER PIPING | Japan Parts EU

 

[JRZEE2000TR4LTD]

Thanks for the link.

Perhaps it was not clear, but I am asking if anyone had the experience of stripping threads on the hard AC pipes, and whether they are bonded with sealant. But I see now that the US 4Runner has hard line connections only at the firewall, which is far less exposed and prone to corrosion, so maybe my question is not a good one

Here is my circuit: TOYOTA HILUX SURFRZN185W-GAMXK - ELECTRICAL - HEATING AIR CONDITIONING COOLER PIPING | Japan Parts EU

Well you can see the oring there so it makes sense that the aluminum just seized together. I've never seen any kind of thread sealant on any vehicle I've worked on.

 

[eurasiaoverland]

Well you can see the oring there so it makes sense that the aluminum just seized together. I've never seen any kind of thread sealant on any vehicle I've worked on.

Thanks. I also find it hard to believe that there is sealant. Think I'll take the risk and buy the junkyard pipes though...

 

[Jantar 2 Standard]

evaporator tube assembly

Yup. I just found the same thread destruction on the joint forward of the firewall (US 2000 T4R) for the larger tube. The male and female threads are both in aluminum and so have experienced galling. The first two or three threads in each part are almost gone, while the deeper threads are still fine.
This makes me leery of putting it together as-is, and possibly losing pressure. I would sure like to know of an aftermarket source for this two tube assembly that bolts to the bottom of the expansion valve. The Toyota part number is: 88710A.
This joint had no thread sealant on it. Maybe sealant is not advisable with R134A gas under pressure.
A parts breakdown drawing calls this the "liquid and suction tube".

 

[eurasiaoverland]

Yup. I just found the same thread destruction on the joint forward of the firewall (US 2000 T4R) for the larger tube. The male and female threads are both in aluminum and so have experienced galling. The first two or three threads in each part are almost gone, while the deeper threads are still fine.
This makes me leery of putting it together as-is, and possibly losing pressure. I would sure like to know of an aftermarket source for this two tube assembly that bolts to the bottom of the expansion valve. The Toyota part number is: 88710A.
This joint had no thread sealant on it. Maybe sealant is not advisable with R134A gas under pressure.
A parts breakdown drawing calls this the "liquid and suction tube".

Not heard of them galling at that joint, must have a lot of corrosion.

Why do you want an aftermarket piece? Original will be better. The number you quote is not a part number, which is always 10 digits, xxxxx-xxxxx.

 

[Jantar 2 Standard]

tube assembly part numbers

The parts page the Toyota dealer printed out for me showed this assembly, including O rings as 88710A. But when I got the bag with the tube assembly in it the number was: 88710-35380. The wholesale price to my garage guys was about $99, while the suggested retail price was shown as $122.xx.
That's why I was hoping to find it as a Denso part from RockAuto for less.
I got the evaporator, drier and expansion valve from them for really reasonable prices.
Bob

 

[TheDurk]

The parts page the Toyota dealer printed out for me showed this assembly, including O rings as 88710A. But when I got the bag with the tube assembly in it the number was: 88710-35380. The wholesale price to my garage guys was about $99, while the suggested retail price was shown as $122.xx.
That's why I was hoping to find it as a Denso part from RockAuto for less.
I got the evaporator, drier and expansion valve from them for really reasonable prices.
Bob

88710A.is not a part number, it is an illustration tag. If the dealer wanted a part number, he would click on the tag and it would take him to the part number qhich would have all ten digits.