need Help for removing rear element of Rollei HFT sonnar 150/4

[mk23]

For cleaning the fungus i need to take down the rear element. i've remove the rear bayonet, but i cant find a way to unscrew the rear element, because its seems too tight or even fixed with screws. does anyone know how to remove it. it looks like that in the figure
thanks very much for the help

 

[gone]

It looks to me that all you have to do is remove that retainer w/ the two slots on either side. It unscrews counter clockwise and you will need a pair of dykes that will stretch that far (may have to file the tips down) and steady hands.

It's usually possible to get to rear elements from the front as well if for some reason you can't get them out from the rear. Watch out for any spacer shim that may be in there once you get that retainer/rear element out. You'll probably have to turn the lens upside down and pop it into the palm of your hand once the retainer is removed to free the rear element.

 

[bdial]

The proper tool for doing that is a spanner wrench
SK Grimes makes a nice one; http://www.skgrimes.com/products/spanner-wrench

Micro-tools is another source.
Using anything else makes it very easy damage the slots or worse.

 

[mk23]

thanks so much for the reply. the retainer in ring form is easy to be removed. i've done it. but the rear lens keep itself so tight in the position, that i cant even rotate it.
so i go another way to try to remove the whole hood with lens complettly (black thin and big one).

does anybody know how and with which proper tool?

sorry for my poor english, i hope it was for you readable

 

[EdSawyer]

A friction tool (rubber stopper) would be the best thing to remove the whole rear cell. If you can get it to fit, a strap wrench would be another option, but it doesn't look like there is clearance. Sometimes a heat gun can help too.

 

[John Koehrer]

A friction tool (rubber stopper) would be the best thing to remove the whole rear cell. If you can get it to fit, a strap wrench would be another option, but it doesn't look like there is clearance. Sometimes a heat gun can help too.

rubber stoppers can be had from ye olde hardware emporium. Get one slightly larger than the diameter of the tube. You will need to apply some pressure to get a solid grip.

 

[mk23]

Thanks eveyone i will try with rubber stopper and report it