Cracked record cleaning pick up tube

I have owned a VPI 16.5 recording cleaning machine for about 1 year. It has generally worked quite well, except for on two occasions, the pickup tube has cracked in the compression fit slot area.

My early speculation is that the issue may relate to the use of steam cleaning with simultaneous vacuum pickup. The pickup tube may thermally expand and subsequently crack within the compression fitting. I usually steam as one step in the cleaning process and I have been careful to minimize localized heating for fear of record warping. Thus, I am surprised if the tube would warm enough to crack.

Has anyone else had this mishap? Any alternative thoughts on the cause for the cracked pickup tube - they are not cheap!
Yes, I have cracked three. Then I started removing the suction tube apparatus when I close the lid and store it away, and have not had another one crack.
Davt +1....

It's a design flaw with the 16.5. If they'd mounted the lid 1/2" higher (or just mounted the lid on top of the case instead of inside it) this wouldn't happen.
I agree with what the others have said, and perhaps another issue, is when you install a new Tube, just install snugly, with moderate force, no need to install with high force, or a hammer! :-)

It is possible heat may be effecting the material?

I wonder too, would the slight softening of the Spring in any way possibly effect the hardness in which the Vacuum Wand comes down upon the record? Mark
Hickory, are you saying that you steam lps while they are actually on the 16.5? I always steam my lps before cleaning with my 16.5 and Audio Desk, but do it manually.

I've had several crack and each time it was because I applied too much force as, markd51 stated, when pushing the tube into the holder.
I had the same problem with tube cracking. Here's the solution: There is a tiny adjustment screw on the "disc" shaped thingie just below the suction arm. The screw faces the front and is easy to see if you take a look. Just loosen the screw and raise the arm slightly. Don't raise it too much or you'll be leaving solution on the record. Just takes a little trial and error.  Re-tighten the screw and you'll be in business. I've gone several years now without cracking a tube. 
Haven't tried oregonpapa's adjustment, but I have a VPI 16.5 and was surprised when I cracked one tube the second month I was using the machine. I always remove the tube before closing the lid, so it wasn't that, it just cracked in normal use, and suddenly I wasn't getting proper vacuum. I have another tube I use, but I taped the broken one up and am still using it occasionally to clean moldy records, just need to replace the tape every so often as it comes unstuck with the moisture. Looking at the way the tube is made it seems like it's a weak point in the design. Conspiracy theories aside, I'm sure VPI is quite happy selling $30 replacements, or you can spend $70 and buy their stronger Delrin tube..