Traction fuel pump

DoubleChevron

DoubleChevron

Real cars have hydraulics
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This is one nice simple little pump. Its amazing the way this old stuff just dismantles for checking and testing.



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I'm pretty sure this is my leak here. The car drains off back to the tank if you leave it sit for a day (and the manual lever won't prime it). See the olive there is miss-shapen. I'll probably need to replace that.

the top seal is very hard and dead. Has anyone come up with a readily available seal that can be used to replace the seal under the glass top ?

seeya,
Shane L.
 
well lthe pump kits are cheap from europe .... which isn't much help so I can move the car around now :) ..... I'll by some cork sheet from the local parts store tomorrow and cut a seal out. it looks like that is all the pump kit contains!
 
Cork sheet is fine.
However there are some variations in quality.
Try to get one with fine cork particles, as the coarse ones fracture and crumble too easily when squished in place.
 
Also try to get an impregnated cork. They are more resistant to seeping through the cork particles.
I agree that they are a wonderfully simple little pump! they also have that beautiful little sight glass to check if fuel is being sucked through from the tank.
 
The cork is able to be purchased from supercheap (of all places). its a very soft cork that is rubber based. The main reason I'm looking at the pump is the car drains off overnight, which means you really need to pull the air cleaner off and pour some petrol down the carby so it'll fire without lots of cranking.

I haven't checked if its still draining back. But the manual lever to operate the pump still doesn't work unless there its already primed and full of petrol. I noticed when it was apart the hand lever would gently suck if pumped, however if you move the lever that the camshaft moves the pump would do loud gulps rather than gentle "puffs".... I wonder if the manual lever is adjustable to lift the diaphragm higher?
 
Interesting. I'm betting this one has never worked properly from day one. I just pulled the air cleaner off and splashed some fuel down it.... its lifted petrol right away, and there is now no bubbles visible through the top of the pump while its running. I'm guessing it won't drain off now. :)
 
It may be that the priming lever is not properly engaged in its slot. It can twist off line during assembly when refitting the diaphragm.
 
DoubleChevron said:
Interesting. I'm betting this one has never worked properly from day one. I just pulled the air cleaner off and splashed some fuel down it.... its lifted petrol right away, and there is now no bubbles visible through the top of the pump while its running. I'm guessing it won't drain off now. :)
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Hi Shane.

So what happens to the petrol remaining the the carby fuel bowl from when the engine was last running. This should be enough to allow the engine to start and then the lift pump should quickly replenish this into the carby?
 
Whippet said:
Hi Shane.

So what happens to the petrol remaining the the carby fuel bowl from when the engine was last running. This should be enough to allow the engine to start and then the lift pump should quickly replenish this into the carby?
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I would have thought that too.... but it seems to drain off quite quickly.... Its probably a week, not a day .... but it always seems to be drained off when I try to start it. I'll need to pull it right down and see how the lever works. I did pull the diaphragm out and a very sloppy rod that feels like it could fall out activates it (it works perfectly when the camshaft moves it).

I'm guessing it'll now be fine.... I'll see tomorrow. the fact there is no bubbles going through the pump any longer, should mean any air leaks are now gone.

seeya
Shane L.
 
DoubleChevron said:
I would have thought that too.... but it seems to drain off quite quickly.... Its probably a week, not a day .... but it always seems to be drained off when I try to start it.
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Hi. Are you inferring that the petrol in the carby fuel bowl is draining back out the needle and seat back down into the fuel pump, and back into the fuel tank?

I would have thought that the fuel in the carby would remain for the next time you need to start your engine?

Maybe it is evaporating from the carby during the period the engine is sitting?
 
Fuel will drain out of pump and the remaining petrol in the bowl may not be enough to start engine. I put a non return valve before the pump on mine. Many people prefer to put an electrical pump in (with safety precautions)
 
Trading Estate said:
Fuel will drain out of pump and the remaining petrol in the bowl may not be enough to start engine. I put a non return valve before the pump on mine. Many people prefer to put an electrical pump in (with safety precautions)
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Interesting. Another trick I guess would be to loop the fuel lineup high so it can't drain back. The best fix would be to strip the pump down and fix the manual lever in this case. I don't mind pumping the fuel up (I do that in the ID19 if its been sitting for any period of time).
 
Hmm :)
The old mechanical pumps were capable of supplying lots more fuel than needed usually so they keep the engine going while running even if not working well. It was the initial starting pump up that then failed. But having a manual lever did help. I think that the old engines just evaporated the fuel in the carby due to the engine heat and the lack of any sealing of the bowl. Later design the fuel was prevented from evaporating so easily into the air. :cool:
I recall years ago helping a guy on the road going to Bathurst up a long series of hills. He spluttered to a halt where we were pulled off having a cuppa. He had been going OK on the flat but loosing power on the hills and had been managing to get up each rise by stopping and then charging up but the current one was too long and he could not get up it. I forget what car it was but I diagnosed a bad fuel pump and on testing its flow could see it was a dribble. So off with the top and the delivery valve bakelite 'flap' was half gone ?? somewhere ? So I cut a piece of leather I found, to fit and put it in. Worked a treat straight off. The guy was waiting at Bathurst for us to get there and thanked up profusly. ;) Ahh the good ol'days !
Jaahn
 
Yes, that exactly the setup in this one. The bakelite pieces look fine, and the very soft springs feel ok. Having said that, its drained off again this morning. I'll order in a pump kit for it, but its unlikely that will fix the issue. If the bakelite pieces and springs look fine, I'm not sure how replacing them will fix anything. I'll need to get the primer lever working.

I have no doubt it'll start now because the fuel bowl will be full..... give it a day or two, and I'll be cranking again.
 
It will be draining off from the base of the spry tower in the carby throat. These towers are fitted with a brass tube that pushes into the casting at the base. They can become loose to the point that the spray tower falls out and drops down towards the butterfly valve. Of course then every thing stops dead. Check that the brass tube is well sealed and is tight. Carefully remove if loose and fix in place with Loctite. (These things break easily so be very careful)
 
Before starting a car, I lift the bonnet and hand prime the fuel pump so the engine will start instantly with the choke "on". Otherwise the starter motor is cranking over longer than normal, just to bring the fuel up to the carby.
With the Traction, the position of the cam, which works the pump lever inside the block, has to be in a certain position to enable me to use it. A quick push of the starter button moves the cam to another position, so I try again.
It's annoying that the later cars don't have the lever on the pump. Off with the hose on top of the carby and "throw" a bit of fuel in ............. to get it going.
 
gerrypro said:
It will be draining off from the base of the spry tower in the carby throat. These towers are fitted with a brass tube that pushes into the casting at the base. They can become loose to the point that the spray tower falls out and drops down towards the butterfly valve. Of course then every thing stops dead. Check that the brass tube is well sealed and is tight. Carefully remove if loose and fix in place with Loctite. (These things break easily so be very careful)
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Oh .... I never, ever, ever touch that. Everyone of those things I've even breathed near has broken :eek: ...... What if I just stare at it with one eye closed while holding my breath (to see if it isn't really cracked or broken off.... Then "pretend" it is fine :) ).

Can that drain off the petrol in the fuel bowl (I would have thought it was the highest point).....

If I'm getting htis right, that drains off the fuel bowl, then the needle and seat open, allowing the fuel to drain back to the tank ?

Edit: I think you're saying the entire tower becomes loose? That I can check. I'm very fearful of touching the brass jet in the top. Everyone of them I've ever touched has "grown" into place (no doubt dis-similar metals) and even the tiniest hint of force by using 1 finger and 1 thumb to hold the screwdriver, breaks the mongrel things off! The alloy threaded housing would only be less than 1mm thick around those threads!
 
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For it to drain back via the needle and seat the fuel would have to flow uphill. This also the reason that the fuel does not drain back via the idle jet, the pump jet or the progression holes. It can only leak out through the base of a badly seated spray tower. Other fuel loss over time can be via evaporation.
 
gerrypro said:
For it to drain back via the needle and seat the fuel would have to flow uphill. This also the reason that the fuel does not drain back via the idle jet, the pump jet or the progression holes. It can only leak out through the base of a badly seated spray tower. Other fuel loss over time can be via evaporation.
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That makes sense. By allowing the pump to drain, I was thinking, while the needle and seat is closed, the fuel shouldn't be able to drain back to the tank (as air cannot get into the fuel line to allow it to drain back). However if the level in the fuel bowl drops, the needle and seat opens, so the fuel will then drain back to the tank. Think of holding your thumb over the end of a hose filled with water. If you lift it up high, the water will stay in the hose .... until you remove your thumb.

The valves in the pump should do this if they sealed 100% perfectly (ie: prevent the fuel draining back).


With regards to the suggestion of fitting an electric pump.... Interestingly "Uncle Tonys Garage" had a video on electric pumps a few weeks ago. his suggestion is to only wire the electric pump to a push button in the car somewhere. That way you can "prime" the factory pump and fill the carby with a button push.... BUT DO NOT RUN THE CAR ON THE PUMP. The obvious reason being if you rupture the diaphragm in the factory pump, the electric pump will continue to push fuel through, and you'll fill the sump with petrol through the fuel pump diaphragm.
 
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