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Subject: Radiator Nipple R&R...(w/ text, references, & pics) Author: WTH as es. WTH (moderator) : member since December, 2003 : 2433 posts Posted on: 2004-08-03 13:03:57

Gentlemen -

The '96 740's radiator is orig. w/ 144k miles. I've been watching it since ~100k and closely for the past 3 months - 'cause it's been giving me the "CHECK COOLANT LEVEL" msg.


Martin's RF Part post


Shawnee's BB post


In the course of a visit to my local dealer's parts dept I picked up the radiator nipple, and this past weekend did the R&R.

Here's the old part in place w/ lots of residue from weeping and evaporated coolant.




I had replaced the expansion tank a couple of years ago (due to crack/leak at bottom-mounted level sensor) and knew that it had to be loosened in order to shift the fan cowling which was necessary to access the nipple's tube clamp (hiding under the cowling). So I removed the plastic bleed screw (don't lose the o-ring/washer) and withdrew the collar by pressing the two tabs inward and lifting. [Don't crack this collar - it retains the top of the expn tank!]

Then remove the two plastic rivets at each top end of the cowling by withdrawing the center post and removing the rivet body. Now the cowling can be shifted upwards enough to get to the nipple's clamp.


On this car, the nipple just came off! And I don't mean that I withdrew it intact from its hole in the radiator top ! It had cracked clean-through and lifted right off when I touched the clamped rubber tube. Here's a pic of these old parts.



I was able to remove the three barbs remaining in the hole w/ a carefully bent wire.
Here are a couple of pics of the removed clamp and nipple. Note the rubber seal is flat (like a rubber band) instead of the o-ring on the new part. and those three barbs on the right.



I bought a 5/8" screw clamp, attached the new nipple to the tube, snapped it in place, reinstalled the cowling (make sure all tabs are locked behind their slots), reattached the expansion tank, and used water to top-off the cooling system.

Once all air was expelled (ran short errands for a couple of days and have had no change in coolant level and no bubbles from bleed screw), all is well. This weekend I'll flush & refill w/ fresh coolant/water mix.

I hope this will last another couple of years...

• Radiator Nipple R&R...(w/ text, references, & pics) (pic) (url) - es. WTH 2004-08-03 13:03:57 (13482 views)
  • been there, done that... (url) - wcsnyder 2004-08-04 03:18:54 (1274 views)
    • Feel free to post your copy here! - DavidC 2004-08-06 15:13:44 (2990 views)
    • Mr. Snyder - I likely saw your RF post last Dec... - WTH 2004-08-06 14:57:57 (593 views)
  • David C. - this sure belongs on e38.org! Nice pics & write up! (nt) - sealbeach740 2004-08-03 18:51:24 (619 views)
  • Hope your repair lasts - farnarkler 2004-08-03 18:08:15 (743 views)
    • Thanks for your good wishes & your argument is valid... - WTH 2004-08-03 20:04:36 (607 views)
  • someone suggested draining some fluid, removing the upper hose and inserting (m) - Martin 2004-08-03 14:22:26 (867 views)
    • Indeed ! (nt) - WTH 2004-08-03 17:19:05 (534 views)
      • Any pieces that fall in will be at the bottom of the upstream side of the core. (nt) - Roy In GA 2004-08-04 00:46:07 (746 views)
  • Good post! (nt) - DavidC 2004-08-03 13:50:05 (589 views)
    • Second That! (nt) - Shawnee 2004-08-03 14:31:38 (629 views)