Fuel priming bulb

oldbilbo

oldbilbo

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The idea may have been mentioned here, but I'm considering fitting a manual-operation fuel primer 'squeeze' bulb in the supply line from my diesel tank to my course fuel filter. I anticipate an easier time if/when I have to bleed the fuel supply after changing the filter element.

Am I re-inventing the wheel?

Reservations? Caveats and quibbles? Enthusiasms...?
 
This aid in bleeding the fuel system has been discussed before and many have used this method.

However it is really only necessary if your engine fuel is gravity fed or by mechanical lift pump. I have replace my faulty mechanical lift pump with an electric pump so my fuel system bleeds well without a 'squeeze' bulb, and the injector pump is well primed before the engine even rotates, giving near instant starting.
 
Enthusiasms here. Installed upstream of the filter, makes it dead easy to bleed out of the filter vent.

The only downside in my installation was that I hadn't anticipated it when I positioned the filters, so the bulb location was a little awkward to reach.

Pete
 
oldbilbo said:
The idea may have been mentioned here, but I'm considering fitting a manual-operation fuel primer 'squeeze' bulb in the supply line from my diesel tank to my course fuel filter. I anticipate an easier time if/when I have to bleed the fuel supply after changing the filter element.

Am I re-inventing the wheel?

Reservations? Caveats and quibbles? Enthusiasms...?
Click to expand...

Reinventing the wheel ... yes ......my diesel car has one!
 
oldbilbo said:
The idea may have been mentioned here, but I'm considering fitting a manual-operation fuel primer 'squeeze' bulb in the supply line from my diesel tank to my course fuel filter. I anticipate an easier time if/when I have to bleed the fuel supply after changing the filter element.

Am I re-inventing the wheel?

Reservations? Caveats and quibbles? Enthusiasms...?
Click to expand...

Added one last year as my tank is well below the tiny fuel pump on my Beta. Makes bleeding a very simple business so well worth the effort
 
sailorman said:
i have "one n stock" but cant bring myself to fit it.
i dont want 135 Lts of diesel in the bilges
Click to expand...

You could perhaps fit it high so that could not happen..Or you could fit it in a loop with two isolating valves and a bypass valve so that it is not in circuit during normal running.

Not had any problem with the car one nor ones on outboard engines.
 
my engine is higher than the tank i only have issues when i change filters. i do have a CAV water trap & integral pump
VicS said:
You could perhaps fit it high so that could not happen..Or you could fit it in a loop with two isolating valves and a bypass valve so that it is not in circuit during normal running.

Not had any problem with the car one nor ones on outboard engines.
Click to expand...
 
theoldsalt said:
This aid in bleeding the fuel system has been discussed before and many have used this method.

However it is really only necessary if your engine fuel is gravity fed or by mechanical lift pump. I have replace my faulty mechanical lift pump with an electric pump so my fuel system bleeds well without a 'squeeze' bulb, and the injector pump is well primed before the engine even rotates, giving near instant starting.
Click to expand...

"However it is really only necessary if your engine fuel is gravity fed"

If your fuel system is gravity fed, why would you need to prime the system?
Many boats have a daytank, which gravity feeds an engine, this being filled using a manual pump.
These daytanks eliminate the need for any priming.
 
alant said:
"However it is really only necessary if your engine fuel is gravity fed"

If your fuel system is gravity fed, why would you need to prime the system?
Many boats have a daytank, which gravity feeds an engine, this being filled using a manual pump.
These daytanks eliminate the need for any priming.
Click to expand...

"If your fuel system is gravity fed, why would you need to prime the system?"

On my boat the fuel level is above the injector pump when the tank is anything over half full and I have had problems bleeding the fuel system until fitting the electric lift pump. Gravity feed usually applies very little head of pressure for getting rid of air compared with the pressure and flow that the electric pump is capable of.
 
One day i intend to run the system dry and see just how many of the 3 low pressure bleed points one can ignore, if indeed any, when using the priming bulb..

I suspect none but you don't really know till you know.
 
Since we're on the subject. Bicycle pump and tube teed in at the primary filter spare nipple, fuel tank valve shut 'off', is a very good away to find invisible low pressure side air leaks too.
 
theoldsalt said:
"If your fuel system is gravity fed, why would you need to prime the system?"

On my boat the fuel level is above the injector pump when the tank is anything over half full and I have had problems bleeding the fuel system until fitting the electric lift pump. Gravity feed usually applies very little head of pressure for getting rid of air compared with the pressure and flow that the electric pump is capable of.
Click to expand...

Then there is something inherantly amiss with your system, since you should be able to bleed all the way to the inlet side of your injector pump using this 'head'. After the inj pump to the injectors, you need to turn the engine over to engage the injector pump.
 
alant said:
Got one in Screwfix - http://www.screwfix.com/p/diesel-fuel-pump-priming-tool/77865?_requestid=439992
Click to expand...

I'm looking to fit one such as this, thanks. But here's a user-review, the first I've seen to express dissatisfaction...

"Utterly useless as a pump.
It doesn't make suction unless you fill it with fuel first, defeating the object of buying a pump in the first place.
When i finally makes suction and pulls fuel through, it leaks out of the joint on the outlet side, rather than push the fuel through a new fuel filter.
Absolute garbage and a waste of time."
Click to expand...

Anyone else echo those thoughts? Or does a well-secured hose clip sort out that issue?
 
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