Series 3 CAV DPA pump, what's the worst that can happen?

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WoodyO

Well-Known Member
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Leaking from the o-ring on the pump head. I've sent my spare pump off for refurbishment but in the mean time I thought I'd whip off the original and give it a go myself.

£55 quid ish for a rebuild kit and 1hr to remove and strip.


 
Leaking from the o-ring on the pump head. I've sent my spare pump off for refurbishment but in the mean time I thought I'd whip off the original and give it a go myself.

£55 quid ish for a rebuild kit and 1hr to remove and strip.



Best of luck. I doubt if you will get that to run again, but you might.

You don't actually need to do all that to replace the O ring, you can just carefully clean the pump, remove the governor housing, and change the O ring. Sometimes you will need to replace the governor housing as well, but last time I bought one it was about 25 quid.
 
Thanks for the words of encouragement :rolleyes:

Pump back together this afternoon after a few hours of fiddling and running as before. Leak gone, just need to set the pump timing again, I didn't mark the position before because it needed doing then too.

Steve, that's the video I used as a guide when putting back together. Good resource.

Agreed, I didn't need to strip it entirely to change the o ring, but it made sense while I had the kit. Yes, possible to do with the pump on the vehicle but in the time it would have taken to faff around with everything in the way, it was quicker to whip it off and do it properly on the bench.

Will time the pump tomorrow morning and grab some photos.
 
Pump back together this afternoon after a few hours of fiddling and running as before. Leak gone, just need to set the pump timing again, I didn't mark the position before because it needed doing then too.

Steve, that's the video I used as a guide when putting back together. Good resource.

Agreed, I didn't need to strip it entirely to change the o ring, but it made sense while I had the kit. Yes, possible to do with the pump on the vehicle but in the time it would have taken to faff around with everything in the way, it was quicker to whip it off and do it properly on the bench.

Will time the pump tomorrow morning and grab some photos.
With a pump on a Series, I wouldn't remove the governor housing with the pump on the vehicle, because, due to the upright position of the pump, the works will fall out when the governor housing is removed.

I would take it off, and put the pump body in a vice to hold it upright, and then remove the governor housing carefully, leaving the works in position on the pump body.
 
Got the pump off the S2 i'm restoring on the shelf couldn't bleed it but all pipes and lift pump were solid with sludge so expect it's the same going to have a go at stripping it to clean...
 
Got the pump off the S2 i'm restoring on the shelf couldn't bleed it but all pipes and lift pump were solid with sludge so expect it's the same going to have a go at stripping it to clean...
Might be worth trying to clean the pump internals with petrol before taking it apart, it sometimes works.
If the pump is off the vehicle, remove the fuel intake union with the little gauze strainer inside, and pour neat petrol into the pump, leave for a while, and try and turn it by hand, see if it frees up. Only turn in the direction of rotation marked on the pump body.

Pump on vehicle, fill a filter element with petrol, put it back on, holding the metal dish tightly against the element to stop the fuel running out, then pump with the lift pump to bleed through into the pump body. If you get fuel at the bleed screws, you can try and start it up and just leave it on idle, the petrol/diesel mix will get sucked in and clean out a lot of gook.
 
Might be worth trying to clean the pump internals with petrol before taking it apart, it sometimes works.
If the pump is off the vehicle, remove the fuel intake union with the little gauze strainer inside, and pour neat petrol into the pump, leave for a while, and try and turn it by hand, see if it frees up. Only turn in the direction of rotation marked on the pump body.

Pump on vehicle, fill a filter element with petrol, put it back on, holding the metal dish tightly against the element to stop the fuel running out, then pump with the lift pump to bleed through into the pump body. If you get fuel at the bleed screws, you can try and start it up and just leave it on idle, the petrol/diesel mix will get sucked in and clean out a lot of gook.

Had to clean fuel tank with thinners petrol made no impresion so will try that...when on engine using a seperate fuel supply and a pump could get fuel to bleed screws but nothing at injectors...
 
Had to clean fuel tank with thinners petrol made no impresion so will try that...when on engine using a seperate fuel supply and a pump could get fuel to bleed screws but nothing at injectors...
Guessing a previous owner/operator has been using "alternative fuels". Veg oil can set pretty hard if left in a tank for a while.
 
Guessing a previous owner/operator has been using "alternative fuels". Veg oil can set pretty hard if left in a tank for a while.

Had been standing for years before I started work on it...when I took fuel filter canister off there was no filter in it...a couple of days later while underneath removing alternator looked over and thought what is that black gunged up thing stuck to top off spring jammed by the swivel it was the fuel filter god knows how long it was there..
 
Had been standing for years before I started work on it...when I took fuel filter canister off there was no filter in it...a couple of days later while underneath removing alternator looked over and thought what is that black gunged up thing stuck to top off spring jammed by the swivel it was the fuel filter god knows how long it was there..
Seen similar, although not for a long time. Working on plant that had been on building sites, I have removed hacksaw blades and handfuls of gravel from fuel tanks and hydraulic oil tanks. I don't think they got there by accident.

In what you describe, I imagine someone has removed the filter element to try and improve fuel flow to bleed the pump, either with fuel, or with some kind of solvent as discussed earlier.
 
Seen similar, although not for a long time. Working on plant that had been on building sites, I have removed hacksaw blades and handfuls of gravel from fuel tanks and hydraulic oil tanks. I don't think they got there by accident.

In what you describe, I imagine someone has removed the filter element to try and improve fuel flow to bleed the pump, either with fuel, or with some kind of solvent as discussed earlier.

The filter canister is on a bracket between battery tray and water pump and was a guddle to remove you have to drop housing down to change canister I think it's been dropped when re-fitting...
 
IMG_20201202_150700.jpg

As found!
 
Pump timed this morning and it's night and day compared to before the refurbishment.

Nice and smooth idle, no chuffing from the exhaust and much less smoke. Barely any at idle and only a bit on hard acceleration.

Definitely recommend to anyone considering doing it themselves.
 
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