Whats the thread size for 81 RR 3.5 oil pressure sender?

[jayk]

Hello...


Does any of the in house gurus know the thread size for 81 RR 3.5 oil pressure sender?

Above the the oil filter mount point there are 3 sensor senders. I want to replace the oil pressure and temp guages and was hoping to find out what size these are first, so I can get any required adapters when getting the guages/senders.

Also, should I use thread tape or fibre washers...or both?

[DEFENDERZOOK]

<span style="color:blue">i think it has a tapered thread.......so thread tape is best.....



if you take the switches with you you should be able to easily match them
to the correct fittings by eliminating the guess work......</span>

[LRHybrid100]

was recently told by a VDO specialist not to use tread tape on treaded sendors as it gives false reading on the gauge!!!

LRH

[incisor]

never put thread tape near any lub line no matter what, it tends to block lines esp when the tape starts swelling.

tis why god gave use liquid thread sealants.

[discowhite]

the thread will be 3/8 BSPT or smaller.
BSPT= british standard pipe taper.

tapered threads were designed to self seal. (think cork in hole)
so the use of thread tapes is usless. unless you have screwed
BSPT into NPT or vise versa.

if anything only ever use a fine amount of sealant.

cheers phil

[DEFENDERZOOK]

<span style="color:blue">heres a question.....how does thread tape get into the plumbing...?

if used CORRECTLY and only on the threads as it should be...
i dont see there being a problem....

the tape is not meant to go over the end of the pipe....just on the threads...
i dont cover the first few threads when i use it....
therefore any threads that may stick through the other side wont have any tape on them...
it really is to only seal the last 3-4 that are actually screwed in.....

i even use it on sump and diff plugs and havent had a problem....
also know of many mechanics that do the same.....

now i think ive been doing the wrong thing all these years......HELP.... </span>8O

<span style="color:green">and possibly even giving dud advice..... </span>ops:

[discowhite]

AFAIK thread tape, also know as teflon tape was primarily designed
to stop brass and other non ferrous metals from binding them selves
together, more as an anti seize would.

the others are right if the thread tape isnt ''wound'' on the correct way
it can dislodge and clog up pressure gauges ect. (most mines and power
stations only use teflon paste.)

so wind the tape on the same direction as the direction of the thread
male bit) so that when you screw the female bit on it dosent ''un wind''
the pape.

and you only really need 2 full turns at the most.

cheers phil.
fitter/machinist by trade, i cant spell but i can weld!

[incisor]

Originally posted by discowhite
fitter/machinist by trade, i cant spell but i can weld!

hey i was one of them once.

teflon paste is much better than tape.

[walker]

I tried to get an adapter for the oil pressure switch and ended up giving up. I took it to an instrument specialist who told me he had tried to get and adaptor thread for the Rangie before and was unable to get it. I wanted it so I could install a mechanical pressure guage. I ended up using the old fitting and tapping a new thread into it so it became the adaptor.

[jayk]

well that doesn't sound to positive...