Bit of a long story but I have isolated a drop in vacuum between the modulator and top pipe, this is after Y junction to diaphragm on side of pump.

Going to have another go at remove/replace, one of the allan bolts is rounded off due to previous attempts despite lowering box.

Couple of questions;

Kent talks about (at 2.48) the cap retaining vacuum on both of these modulators, is this correct as there is no seal inside the cap which is fairly loose anyway.

If the cap does need to be air tight i can search around for another O ring and make good.

Thanks

https://www.youtube.com/watch?v=gM4KZvwsCW0

This video shows the cap/modulator in more detail, I would be surprised if the vacuum relied on the cap rather than say a small O ring around spindle.

https://www.youtube.com/watch?v=GIXR7gNXOws

__________________
David


1996 Mercedes S124 E300TD - 129k - rolling restoration project -

1998 Mercedes W210 300TD - 118k (assimilated into above vehicle)