Petter AA1 seized diesel pump

Hi, I'm new to the forum having bought a water pump with an attached Petter AA1 diesel engine.

I knew it was a non runner and I bought it as a project for fun although a decent water pump may well come in handy.

I believe I have identified the reason the engine won't start and it's the diesel pump.

The governor has an arm that pivots and moves a toothed slide over the body of the pump which in turn rotates something inside the pump that adjusts the flow of diesel and thus adjusts the speed of the engine to its set fixed speed.

The arm moves freely but the sliding part doesn't move. This part here  I know the arm moves freely as you can pop it off the sticking up ball and move back and forth.

I would remove the pump but the sticking up ball bit on the slide has to line up with a cut out in the casting and it's in the wrong position and won't move.

Can anyone make any suggestions as to what I can do?

I have tried filling the pump with penetrating oil but I suspect it doesn't reach the gummed up part - the engine will have stood with filthy diesel for a long time.

Mike

Hello and welcome!

If it is gummed up with old diesel I would suggest trying solvent (brake cleaner?) rather than penetrating oil.

I do have some acetone handy but I was worried for any seals. And it evaporates quickly.

There was a thread about removing the pump a while ago - https://ukengineforum.forumotion.com/t11238-petter-aa1-injector-pump-removal

I saw that post and the pages from the manual were very helpful but ...

I fall at an early hurdle. You need to slide the rack thing that is operated by the governor arm to the centre and that's what's jammed up. Well it won't move so I guess something inside the pump is jammed up. You can buy the part but it means I would have to cut the knob thing off that engages the governor arm which might mean debris in the casing.

At the moment much of the weight of the engine is on the sliding part which is attached to a chain hanging from a rafter. I'm hoping the steady pressure might free things up. I can dream.

drmcw wrote:I do have some acetone handy but I was worried for any seals. And it evaporates quickly.

Brake cleaner is safe for caliper/wheel cylinder seals so you should be OK. Worse case scenario you have to replace the seals.

But from what you describe I do wonder if there is another issue rather than it just being gummed up with old fuel.

I think that whatever the problem is it's within the pump. The governor arm is free to move and I'm not sure that anything else apart from the pump could prevent the sliding bit bit from sliding.

Is it a Bryce or CAV pump or another make.

Maryalice

Bryce FAOAR B series ending in 613 although others fit I believe.

I will see if I have a schematic.

Maryalice

Thank you.

Don't know if it will help, but I have 'A' range workshop manual if you would like a copy.

I have one already thank you and while it helps mine is a silly problem that no manual would cover

In my heart I know I have to cut off the sticking up bit that engages with the governor arm but I really don't want to.

DRMCW,
Can you take a photograph of the pump, all my info is for CAV pumps but the company owned Bryce, CAV  injection pumps maybe similar and I just want to check.
I have cut aways of the single and multi cylinder CAV pumps.

Maryalice

I can't really take a suitable photograph as it's still in the casting. It looks like the B series of this



Part 5 is stuck and mine looks like the lower ball shaped one. I assume that moves part 6 and is some way that regulates the flow of diesel.

Part 5 will not move at all. My forlorn hope is that maybe part 6 is gummed up but if I'm honest it feels like something is totally jammed rather than gummy. There's no sense of give at all. A friend has suggested that maybe the teeth on part 5 have been forced off the end of part six and are dug into the plain not toothed section of metal.

Mike

Looking at a CAV injector pump its internally similar to your Bryce, part 5, the rack rotates part 6, this opens and closes a hole allowing more or less fuel to reach the pump then the injector.
the problem I see is that part 6 and the body will have been made to very close tolerances, almost a perfect seal but still able to move. I doubt that the rack, item 5 has jammed, its likely item 6 has which means you've got to be very careful taking it apart.

Maryalice

Oh dear.

O.k. first I have not had anything to do with this type of pump, but have worked with multi cyl. inline pumps.
I think it most likely that the pump plunger is seized in the barrel (item 2 in the diagram is the barrel and that bit sticking out of the bottom of it is the plunger), if so; the cause would most likely be due to water in the fuel.
If the pump body (item 1) will lift enough to gain access to

Dammit! must have hit the wrong button.
If the pump body (item1) will lift enough to gain access to the screws 3 & 23; I would slacken the delivery valve holder item16 (you would need the pump bolted down to do that), then raise the pump enough to take out the lower screw (I believe that one will locate the barrel) this should allow the rack to move; it should rotate the plunger and that should carry the barrel round with it.
Of course it may be the other screw 23 that locates the barrel, or that may be an erosion plug.

Another thing and it may be a lot easier is:- if you can see, or feel the roller item 17: turn the engine until the cam that operates it, is at its lowest point. If at this point, the roller can be easily lifted (or is stuck up) about the same distance as as the amount of cam lift, then this will indicate that the plunger is seized in the barrel.
If the plunger is seized you could; with the operating cam at it's lowest point: take out the delivery valve holder item16 and items 11 to 15 (careful not to lose any) then you can see the end of the barrel with the plunger inside of it, you can then apply penetrating oil, or diesel, or parafin.
If the plunger is seized or rusted, could then tap it down using a brass drift of a smaller diameter than the plunger and very small hammer.
You would then possibly have to refit items 11, 14 and 16. turn the engine two revolutions; to raise the plunger and get the cam back to it's lowest position, take out items 11,14 & 16 and tap the plunger down again, and possibly repeat this operation several times.
Or give up.
Or some one may have a better idea, or an easier idea.

Thank you so much. I am away for a week or so and will try this advice on my return and update with progress!

I feel some hope.

Right I have a chance to look again.

Sadly the pump body (1) will not move enough to expose screws 3 & 23 so that is a non starter.

I don't have a brass drift but I do have some copper nails that will do the trick so I ground the end of one flat and tried tapping but nothing moved. I'm reluctant to start walloping it but I suppose that's one way I could go.

The pump will rotate a bit but it fouls a rather pointless casting before it rotates enough to let the ball on part 5 to slide into the slot to allow the pump to be withdrawn. I think the pointless casting I have should have an overload stop mechanism which it definitely hasn't got. Anyway if that wasn't there I could probably rotate the pump enough to get the ball to line up with the slot.

I am currently looking at the angle grinder and thinking I might risk trimming a couple of mm off the bit that's in the way. At the moment it does nothing and I can always put a washer there.

Bad idea?

2hrs writing replies; somehow deleted them part way through 3 times
Advised by son:- do it in notebook it'll self save, then transfer it over, done it in notebook, then lost it. soddit!
Final attempt.
With items 11 to16 out; rotate engine a few times. If the plunger does not go up and down
about 5 to 10mm then the plunger is seized at the top of it's stroke.
Do not wallop it as you may damage the seating face of the barrel item2 in the housing item1. a copper drift will be fine.
Other likely seizure points are: the rack item5 in it's bore in the housing item1, and the sleeve item6 around the bottom of the barrel item2.
Your friends suggestion, regarding the rack teeth is also possible (but hard to imagine how it could have happened).
Before your onslaught with the anglegrinder you should assure yourself that the arm will still pass through the slot; as it will be at an angle to the slot, after you rotate the pump, instead of inline with it.

As maryalice says, these pumps consist of precision parts, it don't take much to jam them up, or to bugger them up.
Good luck

Thank you for your persistence!

I have tried rotating the engine and nothing moves so I think the plunger is seized.

My last resort will be to cut off the ball and buy a new rack.

Once again

Thank you

Another way to free the plunger (or at least move it) would be to adapt an injector pipe nut with a grease nipple.
Take out the delivery valve item11,
Stick a steel ball using grease about 1/3 bigger than the hole in the centre of the plunger; over the hole in the plunger (this will only work if there is a round hole in the centre of the plunger; but won't work if it has a slot at one side of the plunger).
Refit items 11 to 16 but leave out the inner part of the delivery valve item11(as this is a one way valve).
Then fit the modified pipe nut.
Connect grease gun and pump. This should with any luck force the plunger down, it should then be possible, with the modified pipe nut slackened; to rotate the engine to get the plunger back up.
If this does work; you may have to repeat the operation a few times to make it a bit freer.

Although this may seem a lot of faffing about, with no guarantee of success; you should bare in mind that, that plunger will have to move to allow you to dismantle the pump. Also you will have to fit a new plunger and barrel (it is unlikely that you will get it to work as freely as needed to govern smoothly).
If you can do it using this method; it is kinder to the pump and less likely to damage it than the hammer method.

Yes I can follow the logic of that and probably the practicalities. Basically you're suggesting that grease is more gentle but doesn't like compressing so will exert a lot of force onto the plunger with no violence.

Also I take your point that this is all easier to do with the pump in place.

In the bits I can see I think it does have a slot on the radius of the plunger so I assume the grease would take that escape route rather than force the plunger down.

Could I use a similar technique using a thin oil rather than grease which might creep down the plunger sides and release it?

I can buy a used but said to work pump for £25 but that one has the ball on the rack broken off.

I'm not going to be defeated by this. I want my sludge pump to work! I bought it as a project so I'm not unhappy that I have a problem.

There was a terrific amount of muck in the fuel tank and also a massive amount on the corroded fuel filter so there may be all kinds of stuff down there.

Is there any way heat could help?