Fitted CAV fuel filter /bleeding

[saltyrob]

Hi Folks,

Boat fitted with a CAV fuel filter with glass bowl on the bottom. Replaced filter today and need to bleed system. Filter is above tank. To avoid having to spend ages pumping fuel through using the lever on the fuel pump ,VP2002, are there any tips for speeding up the process.Is it ok to turn the engine over briefly to to pump some fuel through the system.

Many thanks

Rob

 

[Pye_End]

I take the bolt out the top and draw fuel through with an oil extraction pump. Could also use a fuel bulb pump.

 

[PaulRainbow]

Get a small funnel and a short piece of 6mm fuel pipe, remove the spare inlet plug on the CAV filter head (assuming it has four fittings) and fill with fuel.

You can crank the engine, but in 30 second bursts, too much will cook the starter motor and/or flatten the batteries. Best to pump it by hand.

You can also, i'd strongly advise it, fit a priming pump. You can fit a new filter head with a built in pump, or fir an add-on pump. Check the ASAP website for examples.

 

[philwebb]

As pye-end says take the bleed bolt out of the top of the filter housing. Now get an assistant to blow into the fuel filler ( may need a bit of rubber tubing) close the bleed screw when clear fuel comes out. Now try your engine. You still might have to bleed air out at the engine. There should be a bleed bolt on the fine filter. Use the little lever on the fuel pump for this bit.

 

[philwebb]

The filter head with the built in pump is a great idea. I got mine from eBay. I now use the spin-on filters which are are more expensive but don’t leak. They still have a water drain off at the bottom.

 

[PaulRainbow]

The filter head with the built in pump is a great idea. I got mine from eBay. I now use the spin-on filters which are are more expensive but don’t leak. They still have a water drain off at the bottom.

I never seem to have trouble with CAV 296 filters leaking (that's jinxed the next service), but i do always fit new seals. But, another advantage with the spin on filters is that you can pre-fill them.

 

[pvb]

The little lever on the lift pump works, but how well it works depends entirely on where the camshaft was when the engine stopped. The lift pump is operated by a cam, so if it was at a point where it was operated, moving the lever won't do much. You can sense this by feel. If you rotate the crankshaft (spanner on a pulley nut) you can bring the cam to a point where the lever on the lift pump operates properly, and bleeding is easy.

If you're tempted to turn the engine over on the starter motor to try and bleed the filter, be aware that you're pumping water into the exhaust, and that this water won't be expelled by the exhaust gas, so you run the risk of water-locking the engine. Probably best not to try this.

You can buy inline rubber priming bulbs for a few quid - one of these might help.

 

[rogerthebodger]

Hi Folks,

Boat fitted with a CAV fuel filter with glass bowl on the bottom. Replaced filter today and need to bleed system. Filter is above tank. To avoid having to spend ages pumping fuel through using the lever on the fuel pump ,VP2002, are there any tips for speeding up the process.Is it ok to turn the engine over briefly to to pump some fuel through the system.

Many thanks

Rob

I fitted a tap in the metal bottom of the filter so I could drain water out and allow fuel to be pumped into the bowl by fittent a breed pipe like bleeding brakes on a car.

I also fitted a tap in the metal top so that air can be drawn off to help bleeding.

This showa a bleed plug that I fitted a tap to.

https://www.ebay.co.uk/itm/Aluminiu...Suits-CAV-Filter-Tractor-Digger-/183175759748

 

[tillergirl]

Hi Folks,

Boat fitted with a CAV fuel filter with glass bowl on the bottom. Replaced filter today and need to bleed system. Filter is above tank. To avoid having to spend ages pumping fuel through using the lever on the fuel pump ,VP2002, are there any tips for speeding up the process.Is it ok to turn the engine over briefly to to pump some fuel through the system.

Many thanks

Rob

I just start the engine again! The engine will run on the contents of the pipes and secondary filter and I find that it will run sufficiently to suck through fuel from the tank to the primary (CAV). The engine then stops of course as the air comes through. But I then change the secondary filter (which isn't of course full by then). Priming the secondary via the pump handle is significantly less bother.

 

[lw395]

If you have a shut off valve on the tank output, close it before you start.
Then undo the brass plug in Roger's picture above.
Squirt in clean diesel using syringe, funnel or whatever.
So long as you get rid of most of the air, the engine will likely start and cope with the odd bubble, provided you use a few RPM.

 

[[70521]]

I got rid of my CAV over the winter because it was a total pain in the arse to change the filter as it was behind the engine under my bunk and I am not a contortionist. Invest in a system that has a top loading filter that you can change in about 60 seconds where you can fill the bowl and filter with diesel.

 

[Hadenough]

Bloody hell! Did you loose your hair shirt? You'll be buying a folding prop next.

 

[[70521]]

Bloody hell! Did you loose your hair shirt? You'll be buying a folding prop next.

I am allergic to wool.

Do folding props help with navigation asks man who did a noon sight enroute from Plymouth to Falmouth two weeks ago?

 

[dom]

Do folding props help with navigation asks man who did a noon sight enroute from Plymouth to Falmouth two weeks ago?

How accurate was the fix?

Oh and what time source did you use?

 

[Hadenough]

And why bother? Just head west until you smell pasties.

 

[jiris]

Hi Folks,

Boat fitted with a CAV fuel filter with glass bowl on the bottom. Replaced filter today and need to bleed system. Filter is above tank. To avoid having to spend ages pumping fuel through using the lever on the fuel pump ,VP2002, are there any tips for speeding up the process.Is it ok to turn the engine over briefly to to pump some fuel through the system.

Many thanks

Rob

I am a big fan of rubber bulb pumps fitted before the filters and water separators. They not only make bleeding the fuel system a breeze, but if you try to squeeze them occasionally, any unusual feel may give you an early warning of blockage or leak in the piping. As any extra component in the system they posses certain degree of risk, but if of a good quality and properly installed, this is negligible.

 

[colind3782]

My CAV is easy to take off the bulkhead and I just hold it as low as possible so it fills from the tank then reattach it. However, having just replaced to fuel line from the tank, I've fitted an inline bulb primer pump to make it a bit easier.

 

[[70521]]

How accurate was the fix?

Oh and what time source did you use?

Within 15 miles and for the first one of the year I was quite pleased with that.

I have a Casio Waveceptor watch that updates itself from a radio time signal at 0200 hours each day, so is as accurate as I need.

 

[[70521]]

And why bother? Just head west until you smell pasties.

Practice makes perfect, not sure they make pasties where I am planning to go.

On a Cornish note who makes the best pasty? I was visiting a client in St Austell last summer and when I asked where to get a good pasty was told, "I'd go to Charlestown". We did and they were great.

Personally I prefer a Forfar Bridie :encouragement:

 

[Ruffles]

If you have a shut off valve on the tank output, close it before you start.
Then undo the brass plug in Roger's picture above.
Squirt in clean diesel using syringe, funnel or whatever.
So long as you get rid of most of the air, the engine will likely start and cope with the odd bubble, provided you use a few RPM.

That's what I do. I also make sure the tank is full before I start to give as big a head as possible.
And I don't change the primary filter until I'm sure any air from the CAV filter has worked it's way through.

Haven't had to wiggle the pump thingy for years.