Bit of an overstatment, there's so little in these (and nothing that can be readily replaced) that it's more of a check and clean really. Glad I did as you can see from the cleaning fluid after soaking the pick up tube filter. All that crap is silicone which got there when the plonker who serviced my MK1 just after I got it decided he'd use (large amounts of) it instead of a rocker cover gasket, but that's another story. Haynes / Bentley and others tell you how to check the rotors to see if they're still in spec. Good news is this pump came well within them. Got a replacement Pierburg pump for the MK2 and while it was perfectly OK, when you see the quality of the original it's definitely a notch or two better, I'd say well worth keeping as long as it's in spec. Pressure regulator part was interesting, this one was gummed up a little and sticky, I'm guessing maybe because the pump'd been off the car for so long perhaps letting things dry out, even so might be one to check if you're doing your own.
