Does anyone know the torque spec for the cooling fan switch on the passenger side head? Would the torque be different for iron or aluminum heads?


Kevin

 

I use teflon tape and tighten til you feel it won't leak. app.10 ft-lbs or less

 

Thats what I have always done, I was just curious. I have the 1989 and 1992 factory GM shop manuals but I didn't find the spec in there. The specs for EVERYTHING else is there..... the CTS on the intake is 108 in/lb and the knock sensor is 14 lb/ft..... but nothing on the fan switch or the temperature sending unit on the driver side head.


Kevin

 

I would definitely go easier on alum. threads

 

I'd use anti-seize maybe as well - aluminum reacts with alot of other metals and they chemically 'lock' together - never put steel into aluminum without anti-seize.

 

I have always used Rector Seal teflon pipe dope. Works great. I also use it on head studs.

 

^Yes, pipe sealer is the way to go.

 

You really don't need pipe dope, teflon tape or ant seize, cause the fan switch is brass, and you need to keep the best connection possible.

 

the pipe sealers also provide lubrication for the threads, to help them seat. You need to use something, or it will be very hard to seal the threads get everything tightened properly.

as you thread the parts together, the sealers disperse and you have metal on metal contact, no issues with electrical connection through any of that stuff.

dont use antisieze, the connection will leak. good teflon pipe dope is best, but the tape will work

 

Its pipe thread not a bolt. Using teflon tape is not a good idea, the little bits of teflon get into the cooling passages and stuff. You DO need to use some sort of lubricant when you screw pipe threads into anything. Pipe threads are a friction, metal to metal contact seal. The lubricant allows the threads to slip and not gaul or tear as you tighten the sender into the head. Anti-seize is probably the best for aluminum heads. Only use enough to lightly coat the threads.
The electrical signal comes from the sender not a metal to metal contact with the head.

 

On a single pin thermal switch that opens and closes to ground it sure does need electrical contact to the head. Pipe sealer doesn't leak and provides good contact.

 

I have iron heads, and since the switch was brass I installed it without anything, and it doesn't leak.