Replacement cover for impeller pump

I'm wondering whether a cheap USB endoscope camera-probe wouldn't be a good investment. It should let you identify where the pieces of impeller are lodged.

I have one similar to this and it has saved quite a few skinned knuckles and saved a lot of time. Connected to a notebook PC, it also permits still pics to be recorded and shown to others e.g. diesel engineers :)
 
Most likely be in the inlet to the heat exchanger. You need to remove the rubber cap which is a so and so to replace.
 
I bought a Speedseal Cover and its a lot easier. I also read recently that if you spray PTFE Spray into the housing its easier to pull the impeller out. I wish that I had not read that as when I went to Halfords it was £11 a can.
But I knew I had to buy one as "sods law" would now make an impeller change while underway a necessity and I would be cursing not having bought a can.
 
Angele said:
This little blighter. What can I expect to see / happen when I remove it?
Click to expand...

You'll see the end of the tube bundle, with luck you will find the broken bits of impeller

You will get wet if you don't drain the coolant , and the seawater circuit first!
 
VicS said:
You'll see the end of the tube bundle, with luck you will find the broken bits of impeller

You will get wet if you don't drain the coolant , and the seawater circuit first!
Click to expand...

The coolant will come out??

I expect to get sea water everywhere, but coolant too?

Surely that is supplied to/from the heat exchanger through a different arrangement (within the black rubber cap?) otherwise the coolant and the sea water would mix, or is there something special about the cap that keeps the two systems separate until you remove it?

Stork's comment about removing the hose first is noted. Ta.
 
On my Perkins perama M20 the black rubber caps are stepped and take 2 hose clips. The smaller hose clip seals the sea water side and the larger one seals the fresh water side.

In your picture it looks like the large part of the rubber cap has been painted green. The diagrams on this site are great: http://www.marinepartseurope.com/en/volvo-penta-explodedview-7740690-26-4159.aspx

In my case I had to replace them as there was a leak from the seawater side to the freshwater side causing it to overflow.

I was going to get a Speedseal but when I enquired they didn't have a cover for my Jabsco 4528 pump.

Regards,

Conor

PS When I took it apart I found some bits of impellor in the tube stack!
 
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Angele said:
The coolant will come out??

I expect to get sea water everywhere, but coolant too?

Surely that is supplied to/from the heat exchanger through a different arrangement (within the black rubber cap?) otherwise the coolant and the sea water would mix, or is there something special about the cap that keeps the two systems separate until you remove it?

Stork's comment about removing the hose first is noted. Ta.
Click to expand...

Yes the larger of the two big hose clips secures the rubber cap to the heat exchanger.... when you undo it and free the cap I think you will find that the coolant will run out. It is a Volvo ????

The smaller of the two clips seals outer end of the cap to the tube bundle. when you undo that any seawater in the system will escape.

It's lack of tightness of this smaller clip, or damage to the cap, that can allow seawater and coolant to mix :o

If you do take the cap off inspect the surfaces where it seals on the tube bundle and the heat excahnger body for damage. Replace the cap if in doubt ( but I bet its expensive.)

Something like this:


11695.jpg
 
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VicS said:
Yes the larger of the two big hose clips secures the rubber cap to the heat exchanger.... when you undo it and free the cap I think you will find that the coolant will run out. It is a Volvo ????

The smaller of the two clips seals outer end of the cap to the tube bundle. when you undo that any seawater in the system will escape.

It's lack of tightness of this smaller clip, or damage to the cap, that can allow seawater and coolant to mix :o

If you do take the cap off inspect the surfaces where it seals on the tube bundle and the heat excahnger body for damage. Replace the cap if in doubt ( but I bet its expensive.)
Click to expand...

Yep, its a Volvo. MD2040 (C or D, I think). According to the Volvoparts website similar to, but not exactly the same as, the one in the diagram you have attached.

Bu$$er! If it was just a case of seawater everywhere, then that was something I would be happy to undertake by myself (assuming a pair of pliers in through the hose inlet doesn't do the trick). But if it involves draining down the coolant and replacing it, then I might think twice about doing it without someone supervising what I'm up to. If I screw it up then, at best that will ruin part of my next sailing trip. At worst, it could be expensive.

Food for thought! Thanks.
 
Angele said:
Yep, its a Volvo. MD2040 (C or D, I think). According to the Volvoparts website similar to, but not exactly the same as, the one in the diagram you have attached.

Bu$$er! If it was just a case of seawater everywhere, then that was something I would be happy to undertake by myself (assuming a pair of pliers in through the hose inlet doesn't do the trick). But if it involves draining down the coolant and replacing it, then I might think twice about doing it without someone supervising what I'm up to. If I screw it up then, at best that will ruin part of my next sailing trip. At worst, it could be expensive.

Food for thought! Thanks.
Click to expand...


Here you are then ... below

No problem surely if you loose some coolant. Just top it up with a water antifreeze mix ( use distilled water if tap water analysis is outside the limits given in the manual or buy it ready diluted)


17680.jpg
 
I had all sorts of fun changing a disintegrated impeller on our MD2030c in the middle of the Corfu Straits. Then came the endless fun of extracting the bits from the heat exchanger. In the end, I took both end caps off and employed SWMBO to push a knitting needle through each tube from the rear whilst I caught the bits from the front end. Yes, you loose the coolant from the exchanger but that's just a case of topping it up when the job is over, not at all difficult. However, one little bit worked its way through to the exhaust injection elbow - the bit where the cooling water enters the exhaust. It was not easy to extract but eventually I used a hose pipe and managed to back flush the bit out; mucky and lots of fun for the kids watching on the quay side....

After all of this, I fitted a Speedseal which has made life much easier, as the ease of removal means I no longer put off replacing the impeller..... And the seal agains both the pump body and the impeller face make for improved cooling water flow. Worth every penny.
 
duncan99210 said:
However, one little bit worked its way through to the exhaust injection elbow - the bit where the cooling water enters the exhaust. It was not easy to extract but eventually I used a hose pipe and managed to back flush the bit out; mucky and lots of fun for the kids watching on the quay side....
Click to expand...

Surely if a bit gets that far, it ceases to be a problem doesn't it?

I understood that the concern is about bits stuck in the heat exchanger causing a blockage. Once they have safely transitted this area, do you need to worry any more?
 
Angele said:
Surely if a bit gets that far, it ceases to be a problem doesn't it?

I understood that the concern is about bits stuck in the heat exchanger causing a blockage. Once they have safely transitted this area, do you need to worry any more?
Click to expand...

If it blocks the injection point into the exhaust it'll likely be even more of a problem than one or two tubes in the heat exchanger being partly blocked.
 
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Angele said:
If I screw it up then, at best that will ruin part of my next sailing trip. At worst, it could be expensive.

Food for thought! Thanks.
Click to expand...

How can you screw up something so simple? All you need to do is to remove sufficient antifreeze / fresh water mix to get the level below the heat exchanger, open up the latter and fish out your errant bits, then reconnect everything and re-fill via the filler cap. Its a gravity fill.

When you have run the engine to circulate water, check the fresh water / antifreeze level. Easiest done if you run the engine up to hand warm with the pressure cap loosened off

You should be changing the antifreeze mix every few years anyway, to preserve its anti corrosion properties. So unless you want to be ripped off by the marina you need to do this sort of basic simple job yourself. If anything its simpler than replacing the impellor which you have already done.
 
Speedseal

Angele said:
That's the job. Asked at the boatshow yesterday and everyone stared at me blankly. Thought I was mad.

Any experience of using them?
Click to expand...

I've got one, no problems with it. They have a version which has the cover with a recess machined on the inside with a ptfe disc inside on which runs a brass disc which actually touches the impeller. So instead of the impeller rubbing against the coverplate the coverplate insert (brass) rotates with the impeller and the ptfe disc is the interface between the rotating brass insert and the stationary brass outer cover. It is supposed to cut down the wear on the pump cover which eventually reduces pump effeciency.

I have it fitted on my engine. Disassembled last weekend for a post-season layup check and everything was exactly as it should be. No wear or scoring anywhere. Mind you the engine only has 350 hours on it and probaly only 100 using the new pump cover.

I think the thumbscrews are a nice idea and the slotted cover makes it marginally easier to get everything lined up when reassemblingand you are less likely to drop the cover/screws in the bilge when dis/re assembling. Speedseal also supply a plastic tool which makes it easier to remove the impeller without damaging it or the pump housing. If you buy ask for two of these tools so you can lever on both sides of the impeller simultaneously.

Anything that makes it easier/faster to change an impeller is a good investment in my book.
 
wotayottie said:
How can you screw up something so simple? All you need to do is to remove sufficient antifreeze / fresh water mix to get the level below the heat exchanger, open up the latter and fish out your errant bits, then reconnect everything and re-fill via the filler cap. Its a gravity fill.

When you have run the engine to circulate water, check the fresh water / antifreeze level. Easiest done if you run the engine up to hand warm with the pressure cap loosened off

You should be changing the antifreeze mix every few years anyway, to preserve its anti corrosion properties. So unless you want to be ripped off by the marina you need to do this sort of basic simple job yourself. If anything its simpler than replacing the impellor which you have already done.
Click to expand...

Ok, it's not the emptying coolant and replacing it that concerns me, but the possibility that, on reassembly, I might fail to ensure the coolant and raw water systems remain separate. I do not wish to allow seawater into the engine block and so, for the cost of an hour or two labour from a marine engine specialist, I think I would prefer to let the expert do it while I peer over his shoulders. (Or, perhaps, he'll be willing to oversee me do it).

I've done the RYA diesel engine maintenance course - without it I probably wouldn't have known the problem was the impeller - but the course does not contain enough practical, hands on experience to make me an expert in engine maintenance. Sad, but that is the way it is.

You'll note that almost all my posts are on Scuttlebutt and not PBO. (I only come on this forum for expert advice, for which I am most grateful to you all). That speaks volumes about my desire to undertake hands on maintenance. If I have to do it, e.g. when out at sea, then I will, but in most other cases I'd rather pay to have an expert do it properly ..... I know a very good Volvo man, so I don't have to be "ripped of by the marina"!

I know this'll shock many of you - cause uproar even - but I've always preferred to spend my time sailing, not fixing things.
 
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