Oil Pressure Sensor: which sealant/adhesive to use on threads??

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In the middle of replacing the oil pressure sensor on a 1FZFE and the FSM (Factory Service Manual) recommends Toyota adhesive 08833-00080 (discontinued), or three bond 1344, or Loctite 242 applied to three threads before installation.

I know others have used everything from Permatex high temp thread sealer to RTV (!), FIPG, or Teflon tape, but the concern with those is that they may leave behind particles and pieces that could get pushed into the oil galley if/when the sensor is removed and replaced in the future. Some even say install it dry as the threads are BSPT (British Standard Pipe Taper) which are designed to seal against themselves.

There appears to be at least a couple Three Bond 1344 variants, 1344J and TB1344E, and it's not clear which is the better one to choose. Both appear to be low strength and fast curing.

Also, when replacing the sensor in a system full of oil, the threads will be dripping so any thread locker or sealer will likely not work as designed unless the drippage is stopped and the threads are cleaned off.

And then there's Loctite 242.


Tossing this out for discussion, experts chime in.
 
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JunkCrzr89

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FSM (Factory Service Manual) recommends Toyota adhesive 08833-00080 (discontinued)
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I use Permatex 59235 on all pipe threads in the shop. Never had a problem. I use FPIG a lot but never on pipe thread.
 
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Roger that.

From the FSM: Toyota adhesive 08833-00080 (discontinued), Three Bond 1344 (likely the same as the Toyota part), or Loctite 242 or the equivalent applied to three threads before installation.

So point is, Toyota appears to be saying either of these thread locking adhesives are acceptable??

However when applying to a "wet" engine (oil in the oil galleries) it seems
that an oil tolerant thread locker (Loctite 243) might be a better choice, but even then the threaded port in the oil cooler cover should probably be cleaned of oil before installion, IMHO.

Checking the break away torque of Loctite 242 is around +/- 110 in lbs, for Loctitie 243 it's about double that depending on the size of the bolt. Not sure what level is too much??


 
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In the shop I use any of the 3 interchangeably. FIPG, (usually when installing a short block and there is a tube of open FIPG on the table, lol) thread tape (usually if I am replacing a sensor due to the old one failing), and thread locker if I can't find the other 2 options quick enough...😋
 
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So it seems that if everyone uses what they have on hand and the oil pressure sensor doesn't leak or fall out then it may not be a critical thing.
 
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Searching online seems like some people (not specifcally working on Land Cruisers) don't use anything, they just tighten it up a bit more if it leaks.

Once while out of state the oil pressure gauge on a new to me FZJ80 was reading zero (PO said it hadn't worked in years), but it drove me nuts so I stopped at an independant shop while driving back home (no tools) and asked the mechanic if he could check the oil pressure, which he did (it was fine). I watched as he wrapped a bit of Teflon tape on the sensor and screwed it back in.
 
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Searching online seems like some people (not specifcally working on Land Cruisers) don't use anything, they just tighten it up a bit more if it leaks.

Once while out of state the oil pressure gauge on a new to me FZJ80 was reading zero (PO said it hadn't worked in years), but it drove me nuts so I stopped at an independant shop while driving back home and ask the mechanic if he could check the oil pressure, which he did (it was fine). I watched as he wrapped a bit of Teflon tape on the sensor and screwed it back in.
as long as the teflon tape does not enter the oil port and stays on the threads of the sender unit this is perfectly fine
 
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In the middle of replacing the oil pressure sensor on a 1FZFE and the FSM (Factory Service Manual) recommends Toyota adhesive 08833-00080 (discontinued), or three bond 1344, or Loctite 242 applied to three threads before installation.

I know others have used everything from Permatex high temp thread sealer to RTV (!), FIPG, or Teflon tape, but the concern with those is that they may leave behind particles and pieces that could get pushed into the oil galley if/when the sensor is removed and replaced in the future. Some even say install it dry as the threads are BSPT (British Standard Pipe Taper) which are designed to seal against themselves.

There appears to be at least a couple Three Bond 1344 variants, 1344J and TB1344E, and it's not clear which is the better one to choose. Both appear to be low strength and fast curing.

Also, when replacing the sensor in a system full of oil, the threads will be dripping so any thread locker or sealer will likely not work as designed unless the drippage is stopped and the threads are cleaned off.

And then there's Loctite 242.


Tossing this out for discussion, experts chime in.
People really got to stop overthinking things.
 
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"People really got to stop overthinking things"


Well, maybe. The point of starting the thread was to get opinions on what others had used, but the FSM does state specifically what to use and all the options are similar thread locking adhesives, either Loctite 242, Three Bond 1344, or Toyota's discontinued adhesive.

The way I look at it is a Toyota engineer (or group of engineers) decided what certain specs should be whether it's the torque value of a bolt or whether a bolt should have a lock washer or instead come with thread locker already applied. I figure they had a reason to recommend a specific procedure.

Having said that this specification appears to be one of those things that may not be supercritical, say compared to the FSM recommendation to oil the OEM style head bolts before installation and torquing down for example.

On the other hand, imagine if the oil sensor vibrated out of it's hole while crossing a desert and all the oil was pumped onto the ground (which may be the reason the FSM recommends an adhesive/thread locker)?? By the time you figured it out you could be a few miles from where the sensor dropped out.

So maybe everyone should carry a spare plug with the correct BSPT threads (or a spare sensor) for that possibility?? Might be an idea for a Wits End emergency oil sensor plug key chain @NLXTACY ;)

But then again, how often do they fall out (a very rare occurence)??

It's all good
 
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