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1500 injector pump leaks


Canal321

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Hi,

The injector pump on my bmc is leaking diesel from a couple of places.

sketch-1556408824627.png.e45885442f57d89bba81b310f6ac8e16.png

 

It's a CAV DPA 324 6776 B

 

I've read on here that it could just need a new gasket under the plate and o-rings for the other one.

 

Is this a job that I can do myself? The engine is on the bench at the min, so access is good. 

 

Thanks in advance. 

 

 

 

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As long as you keep all dust away from the work area and wash all parts off in clean diesel before reassembling them wet then yes any competent DIYer should be able to change both but:-

 

1. No sealer/goo to be used on the gasket.

 

2. Make sure the pipe is correctly aligned with the boss on the plate, you don't want the steel pipe pushing the plate to one side.

 

3. When installing the engine make sure the throttle cable is just long enough to push/pull the throttle lever against any throttle stop (although that look slike an old style pump without conventional stops) otherwise it tends to push the spindle to one side so it leaks.

 

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6 hours ago, Tony Brooks said:

2. Make sure the pipe is correctly aligned with the boss on the plate, you don't want the steel pipe pushing the plate to one side.

 

Well advised. Mine started leaking from here after I re-arranged the pipes. The gasket is a thick cork one and allows movement, in my case lifted one side to cause a weep.

 

The OP's photo does hint the same cause of leak.

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Will these leaks stop the engine running? Because yesterday, I rigged it all up on the bench and got it fired up, ran it for around 10-15mins.

Come back today and it won't even try to start, even after re-bleeding it multiple times.. 

 

While i was on it, I took the glow plugs out and Did the drill bit de-coke, took a fair amount of muck out.

 

Next is have a go at these leaks :)

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As long as the fuel lift pump is supplying sufficient fuel I can't see how the leaks will stop the engine. The transfer pump in the end of the  injector pump ensures the pump body is pressurised during use. However if someone has left the one way PRV valve out of the filter head the body might not pressurise so lets have a photo of the top of the filter.

 

Being a BMC my thought would be incorrect/not enough bleeding. How much smoke did it make when trying to start and what colour?

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21 minutes ago, Canal321 said:

Will these leaks stop the engine running? Because yesterday, I rigged it all up on the bench and got it fired up, ran it for around 10-15mins.

Come back today and it won't even try to start, even after re-bleeding it multiple times.. 

 

While i was on it, I took the glow plugs out and Did the drill bit de-coke, took a fair amount of muck out.

 

Next is have a go at these leaks :)

 

The left hand gasket is at lift pump pressure depending on the fuel return pipe and where it goes. If you hand operate the lift pump you might/should see fuel weeping from here.

 

Just seen Tony's post and my thoughts were also on insufficient bleeding. When you slacken off the high pressure unions, do you see much fuel dripping from these when cranking?

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10 minutes ago, Mikexx said:

 

The left hand gasket is at lift pump pressure depending on the fuel return pipe and where it goes. If you hand operate the lift pump you might/should see fuel weeping from here.

 

Just seen Tony's post and my thoughts were also on insufficient bleeding. When you slacken off the high pressure unions, do you see much fuel dripping from these when cranking?

No, the gasket is at transfer pump pressure which is maintained by the PRV in the filter head. The whole pump body is flooded with fuel at transfer pump pressure. The union that is at lift pump pressure is the other one at the outer end of the pump. The fuel then goes through a plastic gauze strainer, regulating valve and vane type transfer pump. All in the pump end cap/hydraulic head. Transfer pump pressure varies but is likely to be higher than lift pump pressure. I don't have access to any CAV data so I can't look up the transfer pump pressure.

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Hi thanks for the help, I got the engine going again after another go at bleeding it. Found a load more air in. I'm sure there are no leaks in my temporary fuel tank and pipe system. When It gets going there is a fair bit of white smoke.

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IMAG0959.jpg

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Edited by Canal321
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I think the pipes and filter connections are fine. Occasionally the valve on the return port 3 seems to collect and block with fibres and dirt but as you now have it running I doubt that is the case here.

 

This is a early design of the pump. The idle adjustment is the angled "carburettor style "mixture" screw.

 

The wetness around that screw suggests that you have been using the bleed screw on the top of the idle stabilisation unadjusted. I know the manual says use it but I have seen too many idle stabilisation adjusters ripped out of the turret because they seem to be glued in. I would advise that you only use the bleed point on the side of the pump body and only use the one on the top in the direst emergency.

 

Bleed the large  banjo bolt on the top of the filter first. Then the 8mm AF bleed screw on the side of the pump - IMPORTANT - keep bleeding for at least 30 seconds after you think you have got all the air out, air seems to get trapped in the pipes.

 

The white smoke is almost certainly vaporised fuel from when it was not starting but may have been injecting a very small amount - what's the compressions like?

 

I am not sure the black rubber leak off pipe is BSS compliant and am fairly sure the plastic hose clip is not.

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2 hours ago, Tony Brooks said:

The wetness around that screw suggests that you have been using the bleed screw on the top of the idle stabilisation unadjusted. I know the manual says use it but I have seen too many idle stabilisation adjusters ripped out of the turret because they seem to be glued in. I would advise that you only use the bleed point on the side of the pump body and only use the one on the top in the direst emergency.

I have read your warnings about using this screw in your previous posts, so I didn't. But after struggling today I thought I must try the top one, I was very careful with it. After it opened it released so much air! 

2 hours ago, Tony Brooks said:

I am not sure the black rubber leak off pipe is BSS compliant and am fairly sure the plastic hose clip is not.

Noted, thanks

2 hours ago, Tony Brooks said:

what's the compressions like?

I have no tool for measuring the compression

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3 hours ago, Boater Sam said:

The zip tie holding the leakoff rubber hose is certainly not compliant and what is that jubilee clip for on the other pipe?

Haha. The zip tie is not my handy work.. I'll sort these bits out after the main stuff is done.

The jubilee clip is holding the plastic pipe that feeds back to the tank, this is part of the temporary tank set up :)

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  • 3 weeks later...

Hi again, 

 

I'm having a go at this diesel leak today, I've undone the little bolt in the end of the shaft , but the shaft won't come out. Is there anything else I need to undo? Thanks 

 

sketch-1557845331036.png.fda148f1c601e8768d0917d195ba802a.png

 

This is what I have now, 

 

1557845523954-534289561.jpg.af67eb14aeb2b67bac38bfbe10990d08.jpg

 

 

Are there any guide to this job?, I did find one on this forum but all the pictures had been removed :( thanks for help

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That is because its the wrong bolt.  take eh cheese headed screw from the top of the unit close to the bolt you took off and then you should be able to pull the shaft out of the pump. the shaft is wasted so that screw holds it in place. You may have to put the lever back on to get a decent pull.

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10 minutes ago, Tony Brooks said:

That is because its the wrong bolt.  take eh cheese headed screw from the top of the unit close to the bolt you took off and then you should be able to pull the shaft out of the pump. the shaft is wasted so that screw holds it in place. You may have to put the lever back on to get a decent pull.

Hi, Is it this one?

sketch-1557850530915.png

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Thats the non reversible governor unit,and quite a bit different to the reversable one that does come to bits easily.From memory the throttle shaft has rack teeth cut into it.....I will have to have a look.

Edited by john.k
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I just checked...that is whats called the "rack and pinion  governor" and is quite different from the reversable unit....................I strongly suggest you refer to CAV Publication C2129E....before you do anything.

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5 hours ago, john.k said:

I just checked...that is whats called the "rack and pinion  governor" and is quite different from the reversable unit....................I strongly suggest you refer to CAV Publication C2129E....before you do anything.

You may well be correct about that but I have had both types apart and can't remember a particular problem with the rack type pumps except possibly you have to take the governor housing off and apart.

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11 hours ago, john.k said:

I just checked...that is whats called the "rack and pinion  governor" and is quite different from the reversable unit....................I strongly suggest you refer to CAV Publication C2129E....before you do anything.

 

Hi, where would I find this document? Is there any chance you could take a picture of the page(s) I need if you have them? Thanks

5 hours ago, Tony Brooks said:

You may well be correct about that but I have had both types apart and can't remember a particular problem with the rack type pumps except possibly you have to take the governor housing off and apart.

I removed the screw you mentioned, still no luck. 

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I dont have a working scanner...........but ,to replace the spindle (pinion) O rings,you will have to remove the assy from the pump.......dont worry,nothing can fall out or come away..............pull out the metering assy by rotating the throttle pinion,and be sure to note lever position  where the rack first meshes..............once the metering unit /rack is out ,the spindle must be removed by first pushing it out one way just enough to remove the o ring ,then with the ring removed ,push it just enough the other way to remove that ring...........then push it out in the first direction.....................the reason for this is the o ring will come out into the hole for the rack bore and jam the shaft ............................Incidentally,this is an automotive governor,with only idling and maximum speed set,and unsuitable for a boat,as it will not hold revs steady under varying load.

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Bought the manual off an internet site, £5.. now the pump lies in bits .... ?

5 hours ago, john.k said:

Incidentally,this is an automotive governor,with only idling and maximum speed set,and unsuitable for a boat,as it will not hold revs steady under varying load.

Hmm , been in the boat for over 30 years...

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