Racor 900 series question

[Mr Googler]

So, I took the top off my fuel filter to see the condition of the filter. I have replacements but thought I would figure things out before replacing them. On opening the top I found the filter part was only about half full of fuel. Is that right?

The filters are lower than the tanks so I sort of expected fuel to come out but on reading there is a ball valve arrangement in the lower section.

My plan was to simply top up when I change the filter. I've had no running issues but I assume this is because it takes fuel from the bottom of the filter section. Could I crack the top open a little whilst running to push air out?

Are there any issues which can cause fuel to back flow somewhere?

 

[superheat6k]

Normally these filters are positioned in the suction line to the on engine lift pump which is drawing fuel from the tank via the pre filter, so if you crack the top securing handle with the engine running you will draw at in, and likely enough to stop the engine in short order.

I simply poured fuel in until brimmed before doing up the cover, although with my polishing rig set up I can prime the filters, but as you say if they sit above the fuel tank then they won't naturally prime.

Having only half the element immersed means only half of it is actively filtering fuel. I think the ball valve acts as a non return valve to allow you to manually prime the filter.

 

[Bandit]

Most modern engines will self prime up to a point.

Check the Racor element clean lift it up and replace if dirty, drain the bowl of crud and water, do not allow crud and water to go through to engine.

The Racor is on the suction side so opening the filter will introduce air not expel it.

take out the O ring and clean with a cloth , wet with diesel to ensure a good seal and a ring that does not bunch up and split.

 

[Plum]

So, I took the top off my fuel filter to see the condition of the filter. I have replacements but thought I would figure things out before replacing them. On opening the top I found the filter part was only about half full of fuel. Is that right?

The filters are lower than the tanks so I sort of expected fuel to come out but on reading there is a ball valve arrangement in the lower section.

My plan was to simply top up when I change the filter. I've had no running issues but I assume this is because it takes fuel from the bottom of the filter section. Could I crack the top open a little whilst running to push air out?

Are there any issues which can cause fuel to back flow somewhere?

The reason why only the lower part of the filter was dirty was because whoever fitted it did not fill the filter housing to cover the filter before fitting the lid. The outlet to the engine is about half way down the filter in the centre tube so once the lid has been fitted no amount of bleeding, or head of fuel from a higher tank, will get rid of any air pocket that is above the outlet. No harm is done other than you are only using half your filter area so it will clog sooner. I suggest you remove the lid and top it up.

The ball check valve is only for instalations where the filter is higher than the tank to stop fuel draining back.

Www.solocoastalsailing.co.uk

 

[Mr Googler]

Thanks for the replies. I will top up with diesel and monitor.

Cheers