Bl00dy bleeding engines

KREW2

KREW2

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Today I changed the separator filter and the engine fuel filter. I've done them before with no probs, today after 2 hours of trying everything I can think of I finally managed to get the separator to fill. Try as I might, I just could not get fuel through to the engine filter. My final ploy was to disconnect the return pipe, cap off the tank connection, and did the same with air with vent. Then I pumped air into the tank through the filler using the dinghy pump. After a further 2 hours I gave up, when I've cooled down, probly by Sunday I'm going to give it another go, My thoughts are to turn the engine over, a VP 2002, for a few minutes with the decompression lever up. Could this work?
 
Hi Keith
I assume when you changed the filters you pre-filled them as much as possible 'before' you put them back,(saves a lot of priming).
My favorite trick is to get my Pela oil pump out, disconnect main fuel line after filters and connect Pela pump, pulls Diesel through in 2 minutes max, disconnect then final bleed or kick engine over!
regards
Mike
 
Assuming that you have not got any air leaks after changing the filters-
Is the fuel tank full? It can help depending on the design of your system, less height to 'pull' the fuel up.
Is the lift pump at its full stroke on the cam? try turning the crankshaft to a different position, maybe a half turn in the right direction.
Cranking the engine over decompressed, on the starter will eventually draw the fuel through, but you will have to bleed it all the way to the fuel injection pump and then the injectors.
A quick check of your lift pump is to disconnect the inlet pipe, and put your finger over the inlet on the pump- you will feel noticeable suction as you work the priming lever if its OK, and letting go the lever with your finger in place, the lever should stay in position or fall back slowly, at least 4 or 5 seconds.
 
Thanks for the reply, I only have a manual oil extractor, I spose a pela pump is electric. Even if I had one I don't know where I would connect it after the engine filter.
 
You have to ask why it did not work.
Is the fuel level in the tank way below the filters and lift pump?- a dry lift pump may not self prime.
Is the supply nearly blocked?
Is the fuel tap switched on?
Is the lift pump faulty?
Is there a leak letting air in upstream of the lift pump.
If it's not too awkward, I would take the lift pump off and test it with a jamjar of diesel.
If there is a suitable connection, I might try pulling fuel through with a pela oil extractor, or large syringe. There should not be much resistance!
Spinning it with the decompressor active usually works, it will help the lift pump prime. Don't overdo this as you can put a lot of fuel into the cylinders. Stop when fuel comes out of the fine filter bleed screw.
If something is not right or marginal, best find it now!
Good luck.
 
Thanks, I was thinking the pump may be at fault so I will give it a go. I disconnected the line from the separator and blew down it I now know that I now only have air in the system up to the engine filter, that's why I pressurised the tank with the dinghy pump. If I can blow down the line I cannot understand why fuel can't be forced through.
 
Hi Keith
The Pela oil pump is manual.
Its one of the best bits of kit I bought.
Get a 6litre capacity one, brilliant for oil changes and little mess, stick the oil pump pipe down your dip stick and just pump and out comes the oil!
Yes connect the pump after the primary filter, this will draw the fuel through up to the exit of the refitted fuel filter,remove pump and THEN prime a bit more till it final comes through or give the engine a few kick overs, works every time and save Bloody Bleeding hours!
Regards
Mike
 
Thanks again, I will somehow connect my pump to the bleed valve on the engine filter and see if I can suck it through.
 
Filling the filters with fuel may speed the job up, but why have such fine filters if you are quite happy to bypass them? It can be a quick way to ruin your main fuel pump, a fine bit of sand or a metal filing too small to see can so very quickly ruin the very fine tolerances to which fuel pumps are manufactured.
Re 'bleeding' remember air can only get into the system before the fuel lift pump, the sections after the lift pump will be under presure and fuel will leak out.
Also carefully check the filter's rubber sealing rings they can sometimes be a pig to fit, the same with the prefilter/sediment bowl.
 
Yes all the options above are good BUT

before you start taking the thing apart

turn the engine through half a revolution then try again - the pump lever could be on the top of the pump cam prime it all you like in this position but nothing will happen - and nothing it seems, has . . . . .
 
I will work my way through all this advice tomorrow, if none works come and fish me out of Portland Harbour /forums/images/graemlins/tongue.gif
Thanks one and all.
 
I had the same problem, if all else fails it could be a worn out fuel lift pump diaphragm, I replaced mine with an overhaul kit from Keyparts.
rgds
Bob
 
Reporting back,
Went down to the boat today, with all my new-found knowledge I felt I could not fail. Filled the tank to the brim, used the oil drain pump, it worked well, after 3/4 mins of vigorous pumping fuel came through to the engine filter. Cranked the engine over half a turn, lift pump started to work, bled the system a little more. Tightened everything up, turned the key and away she went /forums/images/graemlins/smile.gif
 
Well done, it's easy when you know how, eh!

I did the same job yesterday but no problems - except that nice Mr Volvo designed the engine with a bleed screw on top of the filter fitting on one side of the engine, and the manual pump on the other. /forums/images/graemlins/frown.gif
 
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it's easy when you know how, eh!

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This is why I love this forum, you get advice, humour, debate, opportunity and..................tits
 
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