leaky safety valve

Hi All,

I have a leaky safety valve on my engine and wondered if anyone else has had the same and if you did how you fixed it.
thanks

Kev

If they are "whisping" then really the only option is to pull them off strip the down and carefully lap the two seats with some fine timesaver powder if they are bad, if they are only lightly whisping then use regular brass polish as the lapping compound.
You really dont need to go mad, only light amount of lapping is normally needed.
The worst bit is resetting the dam things as the need to be removed each time to adjust them, when I last did the Agri I found it was easier to get the base setting on air then often you'll only need to tweak it a flat or two just to fine tune them.

Dont be surprised to find the pin that goes through the base start to leak badly after you've messed with them, normally that will rust up after a few steamings and stop.

Hiya,
Thanks for the reply
I have been trying lapping with timesaver with not much effect,maybe I need to keep at it a bit more.

I have made a base for them to test on air at first then set properly with steam once I have it sealing properly.

The centre spring tensioner does leak but im not worried about that at the moment,just want to get the valve working right.

thanks

Kev

That surprises me, can you see where its letting by, mine I could visibly see marks on the valves where the issue was and they needed very little work to get them perfect again, although 3yrs on and they are starting to go again.

If you are finding they are still leaking on air you might find when in steam they will be fine, steam has a weird way of sealing its self up

done a bit more lapping with the timesaver and valves only fizzing when soapy water applied,think I will put back on engine and see what happens under steam pressure.Hopefully it works.

thankyou for your replies

Kev

It will be interesting to see how it changes when in steam, at the end of the day a bit of whisping under steam shouldnt be an issue.

I will post results when I next test it in steam.

There is nothing to seal the spring tensioner and that is why it will leak, I bought some M8 stainless steel shim washers and fitted some to the tensioner, this allows it to be tightened down to the safety valve plate and at the correct spring tension and seal. The valves tend to have a whisp of steam from time to time, you can only cure that by lapping them in.

Capricorn1 wrote:There is nothing to seal the spring tensioner and that is why it will leak..............

I did find on mine the first time I disturbed it that it rusted up fairly quickly and sealed, 2nd time it was a little more trouble some and I found winding a bit of PTF tape around the shaft solved it, although I'm not a lover of using PTF tape on anything but it did resolve the leaky stem.

Hi all,
Finally tried it under steam and now much better,it even blows pretty much spot on which was lucky I thought.
Thanks for all your advice

Kev

Kevster wrote:Hi all,
Finally tried it under steam and now much better,it even blows pretty much spot on which was lucky I thought.
Thanks for all your advice

Kev

Glad it all went well, well done on getting them reset, it took me 2 or 3 steamings to get mine on the mark.