Injection needle for bedplate to block seal

Aaron

Sergeant
Nov 3, 2016
451
103
Colorado
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#1
Hey guys, in the midst of an N54 rebuild, and have a question.

The factory torques the bedplate to the crankcase/block, and then injects sealant into the groove between the two.

I have the new injection valves, Locktite sealant, the high torque plunger, and the Locktite primer. I ordered what FCP Euro described as the proper needle, bit it is much to small to fit and seal into the injection valves.

Does anyone know which needle is the proper one to use?

Thanks!
 
Dec 1, 2016
177
73
New York
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0
#2
I just went through this rebuilding my N55.

here is a few tips:

1) Before your do ANYTHING blow compressed air through the block like TIS says to. Ensure air blows out of all 4 holes!
2) Do not put your crank seals in until AFTER you seal the bed plate. This eliminates the chance that you misaligned the seals or didn't push them in enough and they block the sealant exit holes. BMW actually moved to thinner (10mm vs 20mm thick) front crank seal on late model N55s which I am pretty sure was done purely as a convenience thing so that it's easier to see the bedplate sealed properly. Also, sits the seal sits further back it doesn't require as much pressure to push sealant through the tiny slit in the seal.
3) The BMW injection needle WILL NOT work. There is too much back pressure and sealant will blow out of the fill hole instead of pushing out the exits. Don't bother with the neddle!
4) I am not sure if there is a better way, but what I did was I pushed the tube up against the fill hole with A LOT of pressure. Use a towel to keep the tube from hurting your hands. You need to use your body weight to create a seal between the sealant tube and the injection fitting. It takes a lot of effort to keep the seal from breaking. It helps to have a second set of hand to then release sealant into the block per step 5)
5) This take PATIENCE to do right. You need to build up a ton of pressure against the fill hole and then wait for that pressure to slowly push the sealant through the block. Every 3-5 seconds give the tube another turn or two to keep pressure up. Pressure should drop slowly as fluid leaves the tube and goes into the block. It took a good 3-5 minutes of doing this (without letting the seal break) to get fluid to push out the holes. I had to build up so much pressure that the little sealant tube actually blew/pushed itself off the block a few times making a mess.
6) Don't over-do it either... if you turn the knob of the sealant tube too much you risk breaking the seal on the tube plunger (like what happens with a caulk gun).
7) Make sure your local BMW dealer has some sealant in stock. It took me 2 tubes to get this done. Lots of failed attempts.

I don't understand why BMW wouldn't just put a threaded fitting in instead of this stupid needle crap. I guess the reason is because a robotic arm is probably used at the factory which creates a nice airtight seal without needing to be threaded on whereas a human and a stupid little sealant tube can only do so much. An aftermarket fitting with male threads that match the sealant tube would be nice!
 
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Corporal
Free Vendor
Oct 25, 2016
139
86
Houston, Texas
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#3
The Needle is for seal replacements, only. It won't seal on the bedplate valve. It's not designed to.
You need the injection bedplate nozzle, which they do not provide with new tubes any longer.
What's out there, seems to be whats out there. I've not found a separate part number or replacement. Good thing I have a pile of them from previous tubes.
 
Jun 4, 2017
787
178
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#4
The Needle is for seal replacements, only. It won't seal on the bedplate valve. It's not designed to.
You need the injection bedplate nozzle, which they do not provide with new tubes any longer.
What's out there, seems to be whats out there. I've not found a separate part number or replacement. Good thing I have a pile of them from previous tubes.
Can you post some pictures? I'd bet there's a company out there that makes them and sells them.
 

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