Bleeding the fuel system

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96commander

Member
Joined
Mar 31, 2021
Messages
10
Vessel Name
Springer
Vessel Make
Californian 34
I have a 79 Californian 34 with twin t63. Perkins diesels I just purchased it 8 months ago and I want to change the fuel filters. Any suggestions?
Thank you
 
Its not hard unless access is a problem. Change both primary and secondary filters at the same time so you only have to bleed it once. Hopefully the primary filters are mounted below the current tank level so that you can gravity fill them from the tanks.
Be careful with the gaskets on the duplex secondaries. Install them wrong and they choke off the fuel flow.
 
Do we assume you are writing here of the engine-mounted ones, or could it be you want to include some off-engine filters like Racors?
 
Adding an inline electric fuel pump between the primary and secondary filters makes bleeding easier.
 
Just for priming?
I have wondered about this, if not running does the fuel flow freely otherwise.
The original lift pump will pull thru the electric and the electric will push thru the lift pump. Pump valves are one way check valves that force the flow toward the engine. The electric will provide fuel in the event of a lift pump failure. Some people use an electric in place of the mechanical pump. Some small generators come with an electric.
 
The original lift pump will pull thru the electric and the electric will push thru the lift pump. Pump valves are one way check valves that force the flow toward the engine. The electric will provide fuel in the event of a lift pump failure. Some people use an electric in place of the mechanical pump. Some small generators come with an electric.

Thanks, I can stop wondering if that works, verified it does.
 
I refill the racor primaries from the top, so very little air stays in, cleaning up any I puah out when I put the top back on.

For the 2ndary, when installing the new filter, I remove the old, as well as the old top gasket (in the underside of the head), and the bottom gasket. I think there is also an o-ring. I replace all three, noting that the top gasket goes up in the head, not on the top of the filter or it will block the ports on the filter. Then, I place the new filter on top of the bottom bracket.

Now, here is my trick. It works for me, but others have cursed it. I gently squeeze the filter and bottom together and blue masking tape them together around the circumference a couple of times.

I then fill the filter with sea foam (just a convenient source of clean diesel substitute) and reinstall, holding the filter and bottom together as best as I can while I do. In doing so, I spill a tiny bit, so clean it up.

Normally, taking care to fill the racor and doing this with the filter, I don't need to bleed. It starts right up, runs rough for about 2-3 seconds, and I am good.

If you don't do it with your trick, then open the bleed screw on the pump, it is tiny hex nut on the face and bleed there until it is really bled. If you do that, you won't need to bleed at the injectors. If you rush it, you will. And, for the final bit of bleeding past the pump, you'll need to bump the starter a small few times to turn the pump, etc.

Good luck!
 
I refill the racor primaries from the top, so very little air stays in, cleaning up any I puah out when I put the top back on.



For the 2ndary, when installing the new filter, I remove the old, as well as the old top gasket (in the underside of the head), and the bottom gasket. I think there is also an o-ring. I replace all three, noting that the top gasket goes up in the head, not on the top of the filter or it will block the ports on the filter. Then, I place the new filter on top of the bottom bracket.



Now, here is my trick. It works for me, but others have cursed it. I gently squeeze the filter and bottom together and blue masking tape them together around the circumference a couple of times.



I then fill the filter with sea foam (just a convenient source of clean diesel substitute) and reinstall, holding the filter and bottom together as best as I can while I do. In doing so, I spill a tiny bit, so clean it up.



Normally, taking care to fill the racor and doing this with the filter, I don't need to bleed. It starts right up, runs rough for about 2-3 seconds, and I am good.



If you don't do it with your trick, then open the bleed screw on the pump, it is tiny hex nut on the face and bleed there until it is really bled. If you do that, you won't need to bleed at the injectors. If you rush it, you will. And, for the final bit of bleeding past the pump, you'll need to bump the starter a small few times to turn the pump, etc.



Good luck!



Thank you
 
My description of the bleed screw location was probably less than helpful. If your pump looks like mine (hydraulic governor vs mechanical governor), see the attached photo.

There is actually a 2nd one on the pump, but this one, alone, will normally get the job done.
 

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