CurtPalme.com Home Theater Forum

[Nashou66]

[DB Cooper]

Every c-element I've changed (5 so far) has been glued to the bellows with black rtv silicone, so be careful! I would also strongly recommend you run a small bead of rtv around the bellows before reseating the new c-element. Less likely to start leaking over time.

[Nashou66]

[armstrr]

just did 2 last night and sandbagger is doing the 3rd on his own tonight. our procedure called for 1 extra tool and 3 extra parts. the tool was a razor and the extra parts were shiny new bellows (ok, they weren't shiny, but it sounded good).

the red tube appeared to have rust in the glycol...and a lot of it. you could run your fingers over the tube face and draw your name in it. the green was cloudy and the glycol had yellowed, nothing like the green. i'll find out how the blue was tomorrow night.

we also found the screws holding the bellow's stainless retainer ring loose.

the green tube was a squirter. when the fill screw was loosened, it shot a good 1/2 ounce or more out...it got sandbagger good. the screws around the green were especially rusty, much more so than the red.

red and green c-elements both had rtv on them. and we replaced with such, but vary sparingly.

i replaced the bellow retaining screws with stainless...thought that was best. if they are tightened down properly between the bellows rubber and rtv, there should be no contact between the screws and glycol...

[Nashou66]

DId you actually have new bellows or just said that to make it sound good? If you got new bellows where did you find them?

Athanasios

[stefuel]

For just about every application, people seem to use way to much RTV. Also, RTV straight out of the tube acts like a super lube. When used with soft rubber gaskets and seals, to much screw pressure causes the gasket's and seals to squeeze out the sides. It is best to go easy on the screws, allow the RTV to set and then snug them up. A very thin film is all thats required, applied with your finger. Be sure not to get any in the screw holes as it won't compress when you try to thread the screw in.

For this application, if it were my projector, I would not use RTV. I would make sure all mating surfaces were absolutely clean and free from defects, put a thin film of coolant on all the seals and put it together.

[Nashou66]

[Arno P]

[DB Cooper]

[armstrr]

[armstrr]

[stefuel]

I have actually read somewhere (I think it was Tim back in the AVS days) that oxygen permiates the rubber bellows (even under pressure) and is absorbed by the coolant. This is what causes the pressure, sweating and leaks. All that is required to stop the sweating and leaks is to remove the pressure. My suggestion for long term reliability would be to leave a air bubble in the chamber AND upon completion, press in on the bellows, loosen the fill screw and remove about a teaspoon of coolant while still pressing the bellows, tighten the screw and release. This will put the chamber in a neg pressure state. Under those conditions, liquid can not leak out. Eventually oxygen will permiate the bellows and bring the pressure back up again but it will have to expand back to zero pressure first before it can again cause pos pressure.

Another thing to consider when selecting the replacement coolant is thermal expansion. I'm not sure this is listed in the product specifications but it would not hurt to check. I would hope that a quality name brand coolant would have minimum thermal expansion.

[Nashou66]

[armstrr]

[Nashou66]

Hi Guys, I found a new way that increases the odds of getting the C-element out with less or no damage to the Bellow.

I first said you take off the back LC housing brace but I was wrong, you need to slide it back to give you more
working room to get of the Bellow from the back of the housing. First you need to remover the
pins that are used for Schliemfluge adjustments(Also keep the C-element ring in place till we get
the Bellow off the back)


Screw in to the pin an allen or other screw that fits the threads And Pry it out,

Prying out screw and pin




Pin Removed




Next remove any screws that hold front housing to back and dont loose the Springs.



So after you remove the screws and the top and bottom pivot plates you can move the
housing back to gibe more room to the bellow screws and for a razor or flat screw driver to help
pry it off after the metal gasket is off.

Lc outer Housing slid back to give more room



More room on top too !!!



Now more room for allen key !!! Woo Hooo!




Remove all allen screws, then pry off metal gasket.

Gasket removal



[img]Now slide gasket out of way to front of housing[/img]



Now carefully remove Bellow from back of face plate with blade to start then finger
or you can use the blade all the way around if its on there good!!

Separating Bellow from face plate




Front of LC housing removed from face plate



Now take off gasket



Next remove C-Element retaining ring.



Now fold over the bellow onto the C-element and push the whole thing trough the
Housing hole, do it carefully, but it should be ok and not rip.

Folding Bellow




C-element still attached to bellow



Now you can much more easily get a blade to the bellow and
C-Element to separate them.

Carefully sliding blade between Bellow and C-element



C-Element removed and no bellow damage !!!!!!



i hope this procedure is easier than trying to take the C-element out while the metal housing
is still in place. I think it is.

Athanasios

[AnalogRocks]

[AnalogRocks]

[Nashou66]

I made a word document then saved it to PDF for everyone down load. I added it to my Marquee Stuff page on
.mac account

link here Marquee Stuff

Athanasios

[Ohmess]

Dude -- your new procedure works quite well. I followed it to the T and everything came apart nicely. I installed my red C element last night!

[Nashou66]

[Ohmess]

Is there a preferred way to tighten the allen bolts that hold aluminum frame that holds the C element to the tube face? These obviously implement the lens flapping adjustments, and it would seem if I am way off I will have a lot of setup work to do.