Water bowl options for Perkins 4108

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pcatterall

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our 4108 has an 'old fashioned' water bowl. This is the first part of the filtering process followed by the primary and secondary filters.
The bowl in question is a 'standard glass' one ( it looks like those fitted to landrovers) it sits in a metal bowl so any water is not visable.
We check it from time to time but it is not an easy task we never found significant water in the bowl. Following a recent channel crossing however, where the engine was used for 24 hours we detected some power surging and found that the bowl was full of water.
As a side issue we thought we would have to bleed the system but found she started fine, without bleeding, why is this?
Is there a simple exchange we could do to swap the system for one where the level can be seen ( ideally where the water can be drained out without removal of the bowl)?
Many thanks
 
pcatterall said:
our 4108 has an 'old fashioned' water bowl. This is the first part of the filtering process followed by the primary and secondary filters.
The bowl in question is a 'standard glass' one ( it looks like those fitted to landrovers) it sits in a metal bowl so any water is not visable.
We check it from time to time but it is not an easy task we never found significant water in the bowl. Following a recent channel crossing however, where the engine was used for 24 hours we detected some power surging and found that the bowl was full of water.
As a side issue we thought we would have to bleed the system but found she started fine, without bleeding, why is this?
Is there a simple exchange we could do to swap the system for one where the level can be seen ( ideally where the water can be drained out without removal of the bowl)?
Many thanks
Click to expand...

a simple CAV water separator is what we have
 
pcatterall said:
our 4108 has an 'old fashioned' water bowl. This is the first part of the filtering process followed by the primary and secondary filters.
The bowl in question is a 'standard glass' one ( it looks like those fitted to landrovers) it sits in a metal bowl so any water is not visable.
We check it from time to time but it is not an easy task we never found significant water in the bowl. Following a recent channel crossing however, where the engine was used for 24 hours we detected some power surging and found that the bowl was full of water.
As a side issue we thought we would have to bleed the system but found she started fine, without bleeding, why is this?
Is there a simple exchange we could do to swap the system for one where the level can be seen ( ideally where the water can be drained out without removal of the bowl)?
Many thanks
Click to expand...

We had all sorts of problems with our fuel, I don't think that the tanks had been cleaned in the 60 years plus since she was originally launched.

I was given a Perkins glass bowl water seperator last year and a couple of months ago I had the twin fuel tanks cleaned by a professional. It took 4-1/2 hours. I also had the boat safety done. I asked the engineer about the water trap as I'd heard that glass bowls were illegal. Turns out that they're not illegal but shouldn't be fitted in the engine compartment. Great - fitted the water seperator (under the chart table) and a new pair of CAV type fuel filters and it's working great! There was a small amount of water in the fuel pipes which was trapped by the seperator.

All you need to do to remove the water is place a small container under the trap, start your engine and then remove the plug in the bottom. The lift pump provide the fuel (and pressure) to push out the water - no air can get in.

Another benefit of getting the fuel cleaned this way is that 80%+ of the fuel in the tank is re-usable. We put a shock dose of fuel set in the tank plus additional fuel and we now have full RPM available on the engine.

I would strongly suggest the fitting of these water traps if only because you can actually see water and other rubbish and do something about it there and then.

This is only my opinion after having suffered severe fuel contamination and loss of engine revs
 
Last edited:
pcatterall said:
As a side issue we thought we would have to bleed the system but found she started fine, without bleeding, why is this?
Click to expand...

I have the same engine, though they come in different arrangements, and obviously are installed in various ways, especially as to relative height with the fuel tank.



On mine, when I change the primary or secondary filter, I simply bleed them, no need to bleed the injection pump nor the injectors. The fuel return line runs through the secondary filter (the one on the engine), so the air is bled towards the tank. I use an outboard fuel pump to speed up the process, when I pump I can hear air gurgling inside the tank, when it has finished the engine is ready to start.

It may be that your additional glass bowl is located in a position which allows the same process to happen
 
Thanks 'theoldsalt' i like the combined drainable cav from thornycrofts. I have a similar cav as the primarry filter but there is no drain. I guess I could dispense with the glass bowl altegether and simply replace the non drainable cav with the one shown.
Not sure about the threads but I guess mine will be the imperial size.
Can anyone say just how this combined filter works? I guess that the fuel must come from the tank and go first into the lower bowl (so water can sink) and then be drawn up through the filter. If the fuel went through the filter first then I guess that the filter could become blocked with water droplets. I ask because I cant see from the pictures just how this works.
many thanks for the advice and links
 
pcatterall said:
Thanks 'theoldsalt' i like the combined drainable cav from thornycrofts. I have a similar cav as the primarry filter but there is no drain. I guess I could dispense with the glass bowl altegether and simply replace the non drainable cav with the one shown.
Not sure about the threads but I guess mine will be the imperial size.
Can anyone say just how this combined filter works? I guess that the fuel must come from the tank and go first into the lower bowl (so water can sink) and then be drawn up through the filter. If the fuel went through the filter first then I guess that the filter could become blocked with water droplets. I ask because I cant see from the pictures just how this works.
many thanks for the advice and links
Click to expand...

ASAP supplies sell all the items you req to adapt
 
A 24 hour crossing will have shaken up your fuel tank, and the engine will have drawn up water which sinks to the bottom of the tank.
You may think that the water comes from the fuel but can also come from condensation in the winter time, and accumulates below the diesel, only to appear on long trips or rough crossings.
I guess your 4108 is about 30 years old, and so is the rest of the system? This has obviously worked well, and so I would do two things.
Firstly drain the tank and separate the diesel from the dross. This is quite easy to do, as good diesel floats clear of the dross. Refill the tank, after cleaning it.
Secondly, fill the tank full in the winter to prevent condensation
 
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