Leaks from diaphragm on Brittoni 11 T. Big shame

[Paulio]

Hi Guys,
I've been called to replace diaphragm on brittony 11T,ballanced flue w/heater.customer said as cheap as possible.In the last two years she changed the diaphragm on every annual service(just in case... ).
Bought the diaphragm only,change it,on all three attempts to reassembly it I had leaks from the body around the screws.At all times I had the diafragm pointig downwards
Then she called another guy,he changed the full diaphragm kit,no leaks,job sorted.
I feel so bad,I just couldn't do an easy 20minutes job...
- What I've done wrong????
- Should I change the full diafragm kit or there is another little trick I don't know about???

Thanks

 

[namsag]

Might be teaching ya to suck eggs but just make sure face are clean an diaphragm is in the right position also have the 2 face more or less matched up so when you push them together you get first couple of screws in without anything moving off its seating

 

[HarrogateGas]

And on these keep the silicone grease locked away in the tool box.