Help... B & M drain plug drip, drip, dripping

Messages
58
Location
Central VA
I installed a B & M drain plug in my transmission pan and it will not quit leaking from the drain plug.. It is NOT leaking around the mounting bolts, just around the removable drain bolt/plug.. its not dripping a lot, maybe a t-spoon every couple days or so.. I have tightened several times and now is is quite tight but still drips.. I have maybe 2 or 3 threads left showing.. Suggestions?? I was thinking teflon tape (one wrap) near the head of the bolt so the teflon wont go inside the pan.. Side question - How many miles should I go before I drain and refill the transmission to slowly convert it to new fluid?? Brian
 
Messages
205
Location
Missoula
I've heard/read that many people have had the DRIPS with the aftermarket plug. I would asume the Tef Tape would work (and cheap fix), how else can you fix thread seep? Could you maybe find an O-ring to fit on the bolt or buy a new bolt with a ring? Also, I think I'm going to install a tranny pan drain plug myself this summer, I like the idea of refreshing a few quarts of ATF everyother oil change. How easy was the install for you?
 
Messages
3,855
Location
Cape Cod, MA
This is a common problem with the B&M drain plug...just ask the boys on any F150 forum. I've had 2 that leaked and friends have had the problem as well. Interestingly, I heard good things about the drain plugs sold at NAPA and ordered one. Guess what I got? I gave it one more shot and that one is not leaking.
 
Messages
10,060
Location
Central Washington
I had this trouble with one on my dads F150 as well. We put teflon tape on it and awhile later it started leaking again. The teflon disintegrated, I don't know if it didnt like the heat or the oil or what. On my car I just put an LPW +2 pan on it. What it did with the plugs on that was put some RTV on the threads. No leakys.
 
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thatguy

Thread starter
Messages
58
Location
Central VA
WOW.. i read a lot of posts on the B&M and most time the comments said 'no leaks what so ever'..... LOL What sort of RTV would be best for AT fluid?? I am assuming you dont want to get any RTV inside the transmission or is that not a problem?? thanks Brian
 
Messages
10,060
Location
Central Washington
Usually not a problem as long as its dry. There are some transmissions that use a RTV pan gasket. I would think if you are just putting some on th threads you would have no issues.
 
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thatguy

Thread starter
Messages
58
Location
Central VA
thanks for the help.. I am going to drain the tranny this weekend and refill, and I will give the bolt a few wraps of teflon tape since I have some on hand... this is the first refill (after dropping the pan), so if it still leaks with the teflon tape I will still have quite a few more chances to fix it since I have quite a few drop/refill cycles to go wishihadatruck - From what I found online the B&M plug is a 1/8 NPT in size.. Brian
 
Messages
10,060
Location
Central Washington
I do not think that would work. The bolt head is very small. Barely larger than the thread size. I suppose if you could find a bolt with a larger head and the right thread it might work.
 
Messages
446
Location
York, PA
There are two places for this to leak and everyone is addressing only one or the other. If the leak is coming from the bolt/plug in the center that you will remove to drain the fluid, then the tape (use a good quality teflon tape that is chemical resistant, not the cheap stuff from Harbor Freight or Walmart; wrapped the correct direction) should work fine. If the leak is coming from the actual hollow bolt inserted thru the pan, you will have to remove the pan again and possibly try a copper crush washer, o-ring, welding, silicone sealant, etc. I haven't heard of too many people getting this part to ever seal completely without welding it.
 

thatguy

Thread starter
Messages
58
Location
Central VA
 Originally Posted By: Canawler
There are two places for this to leak and everyone is addressing only one or the other. If the leak is coming from the bolt/plug in the center that you will remove to drain the fluid, then the tape (use a good quality teflon tape that is chemical resistant, not the cheap stuff from Harbor Freight or Walmart; wrapped the correct direction) should work fine. If the leak is coming from the actual hollow bolt inserted thru the pan, you will have to remove the pan again and possibly try a copper crush washer, o-ring, welding, silicone sealant, etc. I haven't heard of too many people getting this part to ever seal completely without welding it.
The center/drain bolt is what is leaking... I drained the fluid today and wrapped the bolt with teflon tape and so far it is NOT leaking..Only time will tell though
 
Messages
2,599
Location
in the shop
Nice work BlueOvalFitter! Looks like a 4R70W pan... I just went with the LWP pan w/ the drain plug. Not enough guts to try that on the factory pan...
 
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