OMG!! I don't believe it but I've had a plunger test failure issue for some time on my 1150. You know the one... Pull away, & get a louder & more metallic kerplunk than usual, followed by alternate flashing abs lights. I even had it looked at by Roy Gardner who cleared the faults & reset everything only to get the same horrid, loud kerklank sound that is the tell-tale abs plunger test failure.
So, I figured I had nothing to lose by having a poke around &, armed with the advrider write-up from Terry (huge thanks for the detailed write-up HERE) I set about taking the abs modulator apart.
I didn't need to take the unit off the bike, just removed the tank to access the top of the hydraulics. Sensors & gaps had already been checked, so I didn't do anything else with the electrics, just the hydraulics. I removed the top of each circuit (standard 22mm socket) starting with the front, which is on the right hand side if sitting on the bike & facing forwards. I cleaned out loads of crappy gunge around the top of each plunger, removed the ball bearing & it's seat. Then I took a few cotton buds dipped in fresh hydraulic fluid & cleaned the bore that the plunger sits in. There was all sorts of gunge & small particles in there which must have built up over the years, despite regularly changing the brake fluid. Once it was all cleared out, I put the plungers back in with a smearing of fresh brake fluid, did the same with the cleaned-up ball bearing seats & ball bearings, followed by the cleaned-up tops, fresh brake fluid applied to the o-rings, etc.
It needed a lot of new brake fluid to bleed everything through - both circuits in the abs modulator, followed by all three calipers. Last thing to do was the abs reset procedure (details here) followed by a test ride. Hallelujah...!! Ignition on & I had the simultaneously flashing abs lights, followed by the sweet sound of a normal abs test as I pulled away, followed by perfect abs operation when I carefully stamped on the rear brake. Front brake test had the same perfect result.
The whole procedure took me a steady hour & a half to complete & was an awful lot easier to do than I'd ever imagined. Worth a try if you've had a plunger problem, & I hope you're as lucky as I've been...
So, I figured I had nothing to lose by having a poke around &, armed with the advrider write-up from Terry (huge thanks for the detailed write-up HERE) I set about taking the abs modulator apart.
I didn't need to take the unit off the bike, just removed the tank to access the top of the hydraulics. Sensors & gaps had already been checked, so I didn't do anything else with the electrics, just the hydraulics. I removed the top of each circuit (standard 22mm socket) starting with the front, which is on the right hand side if sitting on the bike & facing forwards. I cleaned out loads of crappy gunge around the top of each plunger, removed the ball bearing & it's seat. Then I took a few cotton buds dipped in fresh hydraulic fluid & cleaned the bore that the plunger sits in. There was all sorts of gunge & small particles in there which must have built up over the years, despite regularly changing the brake fluid. Once it was all cleared out, I put the plungers back in with a smearing of fresh brake fluid, did the same with the cleaned-up ball bearing seats & ball bearings, followed by the cleaned-up tops, fresh brake fluid applied to the o-rings, etc.
It needed a lot of new brake fluid to bleed everything through - both circuits in the abs modulator, followed by all three calipers. Last thing to do was the abs reset procedure (details here) followed by a test ride. Hallelujah...!! Ignition on & I had the simultaneously flashing abs lights, followed by the sweet sound of a normal abs test as I pulled away, followed by perfect abs operation when I carefully stamped on the rear brake. Front brake test had the same perfect result.
The whole procedure took me a steady hour & a half to complete & was an awful lot easier to do than I'd ever imagined. Worth a try if you've had a plunger problem, & I hope you're as lucky as I've been...