Priming bulb - where to put it?

[lindsay]

I have a Volvo 2002 diesel in my 29 foot sailboat, with the fuel line going from the tank to a primary filter/water separator (glass type) then on to the engine filter. Changing the engine filter and subsequent purging is a breeze. Purging after replacing the primary filter is anything but ie filling it up in the first place, juggling with difficult and uncomfortable access, a rheumatic thumb, a stiff neck and those three pesky gaskets of different circumferences in the filter itself.

A solution is, apparently, to change the filter system. A much cheaper solution I understand, is to fit an outboard type purging bulb in the fuel line, particularly to get the primary filter filled to the top where it can be purged easily. Since this little potential marvel costs anything from GBP7 to 14, this would be my choice.

My question: which side of the primary filter should it be installed, between the tank and the primary, or between the primary and the engine filter?

Thanks

 

[Heckler]

I have a Volvo 2002 diesel in my 29 foot sailboat, with the fuel line going from the tank to a primary filter/water separator (glass type) then on to the engine filter. Changing the engine filter and subsequent purging is a breeze. Purging after replacing the primary filter is anything but ie filling it up in the first place, juggling with difficult and uncomfortable access, a rheumatic thumb, a stiff neck and those three pesky gaskets of different circumferences in the filter itself.

A solution is, apparently, to change the filter system. A much cheaper solution I understand, is to fit an outboard type purging bulb in the fuel line, particularly to get the primary filter filled to the top where it can be purged easily. Since this little potential marvel costs anything from GBP7 to 14, this would be my choice.

My question: which side of the primary filter should it be installed, between the tank and the primary, or between the primary and the engine filter?

Thanks

Doesnt really matter, the "suck" and "push" on these is really good. On my MD2030 I put it after the lift pump and before the secondary filter. It worked great, primed in seconds. There could be an argument that it is best there so the lift pump doesnt have to "suck" through it.
Stu

 

[Rigger]

Is it possible you could damage the lift pump diaphragm by pumping fuel through it (ie having the bulb between the primary filter and the lift pump)? I suppose one way round this would be to bleed before the lift pump , but would that be necessary?

 

[rogerthebodger]

I would fit it between the tank outlet and the primary filter inlet.

My thinking is that when you change the filter and if it is not quite air tight pumping the fuel in would show up the leak right away if it was on the outlet of the filter you would not be able to prime the pump due the the air leak in the filter.

I have fitted an electric fuel priming pump between each of my tank outlets and the primary filter inlets for the same reason you wish to fit the outboard priming bulb.

Also look where they are fitted on outboards.

 

[VicS]

Make sure the bulb you fit is suitable for diesel.

I have seen it suggested that the outboard engine bulbs are not.

Peugeot fit them to some of their diesel vehicles. In in doubt a Peugeot one might be a wise choice.

 

[Stemar]

I had a CAV primary such as you describe & had similar problems with making sure I used the right O ring in the right place and getting everything air- & fuel-tight. It was bad enough trying to change the element alongside the club pontoon - doing it at sea, in a blow, which is when, inevitably, it blocked on me - was a non-starter.

I got a couple of spin-on car filters from my friendly (he could afford to be at the prices he was asking!) local car scrappy. A bit of pipe and some taps from ASAP means I now have a spare filter primed & ready to go, plus I'd be confident in my ability to change a filter in pretty much any conditions.

The total cost was around £50, as I recall, with the added bonus that the cartridges - Volvo V40/ Renault??, possibly 19, are the same as the engine filter on my 2003, so one less type of spare to carry..

 

[Latestarter1]

Proper filter heads are not expensive and scrap yard filter heads leave you very restricted as to finding a suitable filter, however what is done is done.

Outboard squeeze bulbs are totally compatable with both gasoline and diesel.

Take a look at the diagram attached, shows both push and pull options, this should help you.

 

[VicS]

Make sure the bulb you fit is suitable for diesel.
I have seen it suggested that the outboard engine bulbs are not.

Outboard squeeze bulbs are totally compatable with both gasoline and diesel.

I thought they might be but was not sure.

Now that Latestarter has confirmed this it makes it easier to source a bulb. Almost any chandler will have them.

 

[Latestarter1]

Do not even need to go to the swindlers, Yep I have made such a fuss about the PROPER way to prime common rail fuel filters on cars and vans most motor factors stock squeeze bulb now..

 

[VicS]

or even ebay

various sizes to choose from too incl metric and imperial

 

[Heckler]

Make sure the bulb you fit is suitable for diesel.

I have seen it suggested that the outboard engine bulbs are not.

Peugeot fit them to some of their diesel vehicles. In in doubt a Peugeot one might be a wise choice.

Vic
not fighting! hydrocarbons is hydrocarbons whether petrol or diesel. If the bulb is petrol proof then it should be diesel proof?
Stu

 

[Heckler]

Do not even need to go to the swindlers, Yep I have made such a fuss about the PROPER way to prime common rail fuel filters on cars and vans most motor factors stock squeeze bulb now..

All the common rail diesels I have messed with have electric pumps in the tank which pumps the fuel through the system, no need to bleed anything, just switch the ignition on and wait a few secs before cranking. The older Pugs had squeezy bulbs to assist the lift pump. No lift pumps as we know them, on common rail diesels!
tu

 

[VicS]

Vic
not fighting! hydrocarbons is hydrocarbons whether petrol or diesel. If the bulb is petrol proof then it should be diesel proof?
Stu

" If the bulb is petrol proof then it should be diesel proof?"
Yes I'd think so. I merely reported what I think I remember reading on here previously. That it will has already been confirmed by Latestarter and is supported by the ads for them.
Previously remembered info duff ... I thought it was you who had said they weren't, but presumably not.

"hydrocarbons is hydrocarbons" ...
If you say so. I bow to your superior knowledge of organic chemistry. It helpfully condenses a good chunk of some of my old text books in to three words. I can now forget all about alkanes, alkenes, alkynes, all those wretched aromatics and polycyclics. Well I could if I'd ever remembered any of it anyway.

 

[Heckler]

" If the bulb is petrol proof then it should be diesel proof?"
Yes I'd think so. I merely reported what I think I remember reading on here previously. That it will has already been confirmed by Latestarter and is supported by the ads for them.
Previously remembered info duff ... I thought it was you who had said they weren't, but presumably not.

"hydrocarbons is hydrocarbons" ...
If you say so. I bow to your superior knowledge of organic chemistry. It helpfully condenses a good chunk of some of my old text books in to three words. I can now forget all about alkanes, alkenes, alkynes, all those wretched aromatics and polycyclics. Well I could if I'd ever remembered any of it anyway.

Vic
I said no fighting!
As you know oil is basically hydrogen and carbon, mixed. I dont want to go down the route of how it is all joined together, in fact I bow to your superior knowledge there! For the purpose of this thread, that suffices to explain why the primer bulbs that are designed for petrol should be OK to use with diesel.
Stu
PS I could, I suppose, get M.Chem First (Hons) to do a paper for us?

 

[Stoshak]

Well, I fitted a 'pattern' bulb from a motor factor a couple of years ago and the bulb turned rock hard in a season. Interior rubber bits appeared to have dissolved.

Replaced it with a Peugot bulb and all is OK.

 

[VicS]

Vic

As you know oil is basically hydrogen and carbon, mixed.

God Lord ! I never knew that. I'm not even sure i know how to mix them. They'd separate again pretty darned quickly even if I managed it I think.

 

[prv]

I have an outboard bulb just before the primary filters. It's important to have it near them rather than near the engine (if the two are in different places, as mine are) because it's the primary filters that really need the bleeding. My engine seems to manage to bleed itself with a few turns on the starter motor. I wouldn't expect to damage the engine lift pump with a squeeze-bulb pump - some people still have day tanks with a fair head on them, so pressure all the time.

My bulb said on the packet it was OK for petrol and diesel.

I replaced the single CAV filter, which looked fiddly and inaccessible, with a pair of spin-on Racors and changeover valves. The valves are arranged in such a way that the handles block access to the in-use filter and leave open the standby. That way you can't take the wrong one off! When I change over in "normal" conditions, I run for a short while on the new standby so I know it's primed and ready to go if needed.

Pete

 

[Heckler]

Well, I fitted a 'pattern' bulb from a motor factor a couple of years ago and the bulb turned rock hard in a season. Interior rubber bits appeared to have dissolved.

Replaced it with a Peugot bulb and all is OK.

I would say that the "pattern" bulb would have hardened with what ever you put thru it.
Stu

 

[Heckler]

God Lord ! I never knew that. I'm not even sure i know how to mix them. They'd separate again pretty darned quickly even if I managed it I think.

I tried to not fight but you couldnt resist it.
Stu

 

[VicS]

I tried to not fight but you couldnt resist it.
Stu

You should not have fired the first shot then:-

Vic
not fighting! hydrocarbons is hydrocarbons whether petrol or diesel. If the bulb is petrol proof then it should be diesel proof?
Stu

All I had said previously was that I had seen it suggested that outboard bulbs were not suitable for diesel .... FACT ... even though I dont remember excatly where.

On that basis I suggested that the OP made sure that any bulb he fits is suitable for diesel........ and recommended a Peugeot one.
That is still sound advice esp bearing in mind Stoshak's experiences.