I just installed a set of stainless oil cooler lines from mazdatrix this weekend. After the initial testdrive, i found that two of the three connections are leaking. I snuggeg both of them up a little more with no luck. Does anyone know if i should have used that thread sealing material?? (can't think of what it is called now) Thanks for the help.

 

It depends on which lines you got. Anything with a banjo bolt should be self sealing via the copper washer. But AN fittings should be sealed with teflon tape, or pipe dope.

 

I have to disagree with you Aaron. I have 20+ years’ experience in Nuclear and Submarine SUBSAFE piping assemblies and Quality assurance. Teflon tape will expand the tolerances of the mating threads. Once you use Teflon tape you must always use Teflon tape on that fitting and even more with each use. If it is leaking there is a problem with the fittings, most likely the original fittings. TEFLON TAPE IS A BAD BANDAID.

Carroll Smith (Engineer to Win, Tune to Win etc.) doesn't advocate its use. I'm reasonably sure that Aeroquip, Russell and Earls won't advocate its use. AN fittings were designed to be leak free without the use of sealers. You have a problem either:
a. In the mating thread
:or:
b. In the assembly of the hose itself

From Aeroquip:

http://www.aeroquip.com/pages/techinfo.html

Q: Should I use a thread sealant?
A: Only tapered pipe threads require a thread sealant or Teflon tape. The seal takes place by a wedging action of the mating threads, and a pipe sealant is required to produce a leak-free joint. It also helps lubricate the thread surfaces to help prevent galling. Sealing material is not recommended on any other type of threaded connection.

Q: How many times can I reuse my fittings and adapters?
A: Inspect sealing surfaces and threaded connections for signs of damage. If they appear to be in good condition, they may be reused. Tapered pipe thread connections are distorted each time they are reinstalled. Often after 3 or 4 tightening sequences the threads are stretched or distorted beyond practical reuse.

 

Because the fittings are Banjo I highly do not recommend the use of teflon tape.

You should have replaced the copper crush washers when installing the new lines. If you didn't or you over torqued the lines when installing them it can cause the leaks that rgordon1979 is talking about.

rgordon1979 did you tighten the fittings to 33~40 ft-lb???

 

Did you use new crush washers? Mine are leak free, with new washers.

PaulC

 

i made a mistake once and put the washers on only one side of the banjo. simple mistake .... just hoping to help.
maybe it's something simple also
good luck
robert

 

yeah, i used the new copper crush washers supplied with the lines. I did not use a torque wrench, but I will tackle that this weekend. just guessing, but i don't think i torqued them as high as 33-40 ft lbs. Thanks for the help.

If it turns out that i do have them between 33 and 40, what do you think i should do? replace the crush washers and try again?? Thanks again for the help.

 

oh, and i did use the crush washers on both sides of the banjo rpv...

 

Yep, if you over torqued it then you will have to replace them, if you under torqued it, just crank it up to the correct amount with the exisiting crush washers