Decided to poke my HP pump... (warning: pic heavy)

[Poodle]

So, got this spare HP pump and dream of rebuilding it, got some tools through the other day so got down to taking it apart. Thought i'd take some pics in case anyone else was interested. I suspect some of the components aside from the piston itself are not universal across the pump, as this was the one that has the TPD.

Top Tips (Ignore at your peril/expense!):

1. [COLOR="red"]!!! Wear latex gloves, the salt and dirt on your hands will cause the internal parts to rust really quickly. !!![/COLOR]
2. Have 3 tubs half-full of clean diesel to put all the small parts in. Also want a larger tub full enough to submerge the housing; the internal surfaces of this are just as susceptible to corrosion and are a whole lot harder to clean once they do rust up.
3. Keep parts from each piston/cylinder separate, they must go back together in exactly the way they came apart.
4. KEEP EVERYTHING IMMACULATELY CLEAN! Parts must go straight into the tub of diesel when disassembled; they're a bugger to clean properly.
5. The cam rider is not held onto the cam in any way, careful it doesn't slip off and head for the floor as you pull the spindle and cam from the housing.
6. There is a small, round piece that slots into a recess inside the housing, don't forget where or which way round this goes. The indent in the piece is the spring cup, that should tell you which way it goes.
7. There is a small spring behind the above part that makes it nigh-on impossible to refit without faffing about with bits of wire, pliers, a helper and a whole bag full of swear-words.
8. Ignore Haynes' torque setting for the FPR bolts, it's guaranteed to round them off.

Essential Tools:

1. Impact Driver
2. Bench Vice
3. Lump Hammer
4. Tweezers
5. Gloves! lol



Unfortunately, I've managed to persuade one of the torx heads to round off already, poxy crap, so can't go any further yet:



Solution? Bigger hammer me thinks. Did get two of the chamber caps off first though, this is a picture log of the dismantling of one of the pistons:



Apologies if some of the pics are still coming out upside-down, photobucket's being a pain.





Sorry for the crap quality, seems the camera doesn't like close-ups.



I know you can't really see it, what i'm holding there is a small conical spring.











All the pieces in exploded-view:





Some pics of the cam rider moving around at the bottom of the chamber:







Having thoroughly failed with my first attempt, over the next few weeks i will be trying again. I will strip both pumps and transfer the new seals to my old pump, except this time i shall do it properly and hopefully produce a working item at the other end. Taking all bets now... 14/11/11

[Paul_13]

Bit of a holy thread resurrection but did you get any where with this?

[Poodle]

Ah, no, i didn't. Unfortunately my mother-in-law knocked over the box of carefully ordered parts and they got mixed up. Due to the super-fine operating tolerances and the parts already having worn in the piston assemblies had to be assembled as they came out, having mixed up the parts meant that i was trying to rebuild the assemblies with the wrong parts. Despite trying what felt like scores of permutations i couldn't get all three to work smoothly at once, so i sacked it off as a bad job and chalked it up to experience. There were also a couple of springs and shims that fell out of the pump housing when i removed the central cam shaft and struggled like hell to replace - about three hours work for my Dad and I, my dad used to be a hydraulic pump engineer, so you'd expect him to be more help than your average bear - and i'm still not sure we got them back in right.

I'll try most things and will always encourage people to try it themselves if i think it's doable, but i think this is something best left to a specialist with the equipment and information available to do it properly. Having since further researched the subject i'm also aware of exactly how fine the tolerances are, how you need a huge variety of shims and springs available to make necessary, tiny adjustments, and how much the specialists rely on their testing equipment and manufacturer specifications to make repairs, without which it is simply not possible to do the job properly.

That said, please prove me wrong, i'd love to know how to get around the inevitable cost factor.

[toseland]

i am sure piggy will be along sometime to tell you how he did it with a can of spraypaint, a welder, and a hammer, twice as fast as the experts and at 1/16th the cost.

[Piggy]

i am sure piggy will be along sometime to tell you how he did it with a can of spraypaint, a welder, and a hammer, twice as fast as the experts and at 1/16th the cost.

What is your issue? Go lick a cactus.

[mattydturb]

Any of you lads know where to get a reconditioned hp pump from

[Poodle]

Any decent bosch or general diesel specialists should be able to sort you out. Be wary of anything too cheap, don't expect change from £300.