Birdseye
Well-Known Member
The Lucas CAV DPA diesel injection pump on my CASE 580se was a leaking mess and the engine was no longer starting. After watching all the videos on YouTube of the procedure, I bought the required new parts and ran thru the procedure myself. Although time consuming to do this the first tiime, the result was very successful, the leaks are gone and the engine starts immediately, like it never did before.
The pump was extremely dirty outside and inside and it took a lot of time to go thru the procedure carefully disassembling, making notes with pictures and cleaning the parts which were covered in 35 years of accumulated sludge.
I did not remove the transfer pump rotor from the ‘hydraulic head’, that’s the piece the vanes sit in. I did remove the pump plungers and carefully cleaned them and their ports until they slid freely back and forth. In my case, the accumulation of fuel deposits was interfering with plunger movement. Once the plungers were clean and manually primed with a bit of fuel forced in with a syringe, I could actually feel the plungers pressing outward against my fingers. Or if I held one plunger in while priming with an oil filled syringe, I could then push in one side and the opposite plunger would be pushed out. The combined amount of plunger movement is probably less than ¼” but was now unrestricted.
Once the rebuild was completed, for bench testing the pump I devised a small , 1 cup, fuel reservoir to feed the pump and used a cordless drill with a socket to spin the pump. With this I could then see the injection pump shooting a bit of fuel 2-3 feet straight out each banjo pipe as the pump turned. After this I felt confident the pump was working correctly.
My lessons learned , things I should have done better from the start:
- First, watch all the videos and read all the documents
- make careful notes and take lots of pictures that show the order and position of each part as it is removed, time spent on this will definitely save time later
- the position and order of each part is critical and no I wont remember
- a soft wire wheel works well for removing crud from non-precision fit parts
- Alcohol works ok as a cleaner/solvent
- Final clean is a dip in solvent followed by blow drying with compressed air to remove any bits of dirt or cloth fibers
- New ZipLock baggies are good clean containers to hold and organize the parts as they come off and are cleaned .
- Use the torque specs for reassembly, some fasteners are delicate and some need more than I thought in order to not leak fuel
- Some witness marks are helpful for final alignment
- Important: A method for bench testing the pump so you can see it shooting out the diesel fuel 2-3’ from each line BEFORE re-installing the pump is mandatory to remove ANY doubt about the success or failure of the rebuild
- Complete bleeding of the fuel system after pump re-installation is mandatory to remove any and all air, starting with removal/filling both fuel filters, thru all fuel bleeders, high pressure fittings at pump and ending at injectors.
- If fuel isn’t ‘spitting’ but only seeping from cracked-open high pressure fitting, something is wrong , air still in lines, it will never start, redo bleeding .
- No smoke from exhaust? Something is wrong, it will never start, don’t bother with starting fluid, redo bleeding.
Parts I used:
- CAV injector pump rebuild kit 7135-70/7135-110 , SPACO made in Italy $24
- Two oil seals for the drive axle are not included in the above kits so had to be ordered separately ( CAV Lucas 5393-252R DPA injection pump drive seals) $11/ea
- A second large triangle gasket is required, the kit only includes one.
- Pump blades/vanes $11
Manuals and documents, these include functional descriptions, disassembly steps, torque values etc:
https://injectionpumps.co.uk/cav-dpa-manuals/
or
https://www.fujiyachts.net/manuals/CAV DPA Pump Rebuild Manual.pdf
Interactive parts diagram
https://injectionpumps.co.uk/interactive/interactive-cav-dpa-parts-diagram.htm
The pump was extremely dirty outside and inside and it took a lot of time to go thru the procedure carefully disassembling, making notes with pictures and cleaning the parts which were covered in 35 years of accumulated sludge.
I did not remove the transfer pump rotor from the ‘hydraulic head’, that’s the piece the vanes sit in. I did remove the pump plungers and carefully cleaned them and their ports until they slid freely back and forth. In my case, the accumulation of fuel deposits was interfering with plunger movement. Once the plungers were clean and manually primed with a bit of fuel forced in with a syringe, I could actually feel the plungers pressing outward against my fingers. Or if I held one plunger in while priming with an oil filled syringe, I could then push in one side and the opposite plunger would be pushed out. The combined amount of plunger movement is probably less than ¼” but was now unrestricted.
Once the rebuild was completed, for bench testing the pump I devised a small , 1 cup, fuel reservoir to feed the pump and used a cordless drill with a socket to spin the pump. With this I could then see the injection pump shooting a bit of fuel 2-3 feet straight out each banjo pipe as the pump turned. After this I felt confident the pump was working correctly.
My lessons learned , things I should have done better from the start:
- First, watch all the videos and read all the documents
- make careful notes and take lots of pictures that show the order and position of each part as it is removed, time spent on this will definitely save time later
- the position and order of each part is critical and no I wont remember
- a soft wire wheel works well for removing crud from non-precision fit parts
- Alcohol works ok as a cleaner/solvent
- Final clean is a dip in solvent followed by blow drying with compressed air to remove any bits of dirt or cloth fibers
- New ZipLock baggies are good clean containers to hold and organize the parts as they come off and are cleaned .
- Use the torque specs for reassembly, some fasteners are delicate and some need more than I thought in order to not leak fuel
- Some witness marks are helpful for final alignment
- Important: A method for bench testing the pump so you can see it shooting out the diesel fuel 2-3’ from each line BEFORE re-installing the pump is mandatory to remove ANY doubt about the success or failure of the rebuild
- Complete bleeding of the fuel system after pump re-installation is mandatory to remove any and all air, starting with removal/filling both fuel filters, thru all fuel bleeders, high pressure fittings at pump and ending at injectors.
- If fuel isn’t ‘spitting’ but only seeping from cracked-open high pressure fitting, something is wrong , air still in lines, it will never start, redo bleeding .
- No smoke from exhaust? Something is wrong, it will never start, don’t bother with starting fluid, redo bleeding.
Parts I used:
- CAV injector pump rebuild kit 7135-70/7135-110 , SPACO made in Italy $24
- Two oil seals for the drive axle are not included in the above kits so had to be ordered separately ( CAV Lucas 5393-252R DPA injection pump drive seals) $11/ea
- A second large triangle gasket is required, the kit only includes one.
- Pump blades/vanes $11
Manuals and documents, these include functional descriptions, disassembly steps, torque values etc:
https://injectionpumps.co.uk/cav-dpa-manuals/
or
https://www.fujiyachts.net/manuals/CAV DPA Pump Rebuild Manual.pdf
Interactive parts diagram
https://injectionpumps.co.uk/interactive/interactive-cav-dpa-parts-diagram.htm
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