06-01-2024, 11:59 AM
A guy on UKGSer suggested that his clutch started to drag before slipping at 42,000 miles (strange). I've more miles than that so I took the bike out and tried to get the clutch to slip. Full throttle in 2nd does lift the front wheel! No slippage apparent.
Bleeding/flushing the clutch requires removal of the starter motor. I found that removing the exhaust system and having a short 30 Torx L tool made that job easier.
I flushed through with new fluid. I didn't have a hose of a small enough diameter (it's a tiny bleed nipple- Magura cycle sized) to look for air coming out and I just bled it into a bowl. The clutch was better. Not perfect but I could now turn the rear wheel by hand in 1st much easier than before. I was struggling to push the bike out of the garage in gear previously.
When cycling the clutch with the reservoir open I could see an emulsion of micro bubbles entering the reservoir when I released the lever. A symptom of failing master cylinder seals.
I rarely use gear shift assist and on the roads I ride I'm up and down the box all the time. So the master cylinder has seen a huge amount of use.
The master cylinder isn't a serviceable item. I bought a low mileage one from a R1250RS from eBay.
Having acquired the correct size bleed hose I went back to removing the exhaust system and starter motor etc.... I pulled the slave cylinder out to check it wasn't leaking and had a shock when oil dripped all over the floor, thankfully it was engine oil, red not blue. So the slave is good. I couldn't get the pushrod to separate from it though.
I fitted the replacement master cylinder and bled though with new fluid. I even back flushed by pushing the slave cylinder in several times, no air!, no micro bubbles.
New seals on the hose, new exhaust gaskets and the bike is all good. In 1st the rear wheel turns quite freely with the clutch held in.
Sorted. Updated in case anyone has the same issues.
Peter
Bleeding/flushing the clutch requires removal of the starter motor. I found that removing the exhaust system and having a short 30 Torx L tool made that job easier.
I flushed through with new fluid. I didn't have a hose of a small enough diameter (it's a tiny bleed nipple- Magura cycle sized) to look for air coming out and I just bled it into a bowl. The clutch was better. Not perfect but I could now turn the rear wheel by hand in 1st much easier than before. I was struggling to push the bike out of the garage in gear previously.
When cycling the clutch with the reservoir open I could see an emulsion of micro bubbles entering the reservoir when I released the lever. A symptom of failing master cylinder seals.
I rarely use gear shift assist and on the roads I ride I'm up and down the box all the time. So the master cylinder has seen a huge amount of use.
The master cylinder isn't a serviceable item. I bought a low mileage one from a R1250RS from eBay.
Having acquired the correct size bleed hose I went back to removing the exhaust system and starter motor etc.... I pulled the slave cylinder out to check it wasn't leaking and had a shock when oil dripped all over the floor, thankfully it was engine oil, red not blue. So the slave is good. I couldn't get the pushrod to separate from it though.
I fitted the replacement master cylinder and bled though with new fluid. I even back flushed by pushing the slave cylinder in several times, no air!, no micro bubbles.
New seals on the hose, new exhaust gaskets and the bike is all good. In 1st the rear wheel turns quite freely with the clutch held in.
Sorted. Updated in case anyone has the same issues.
Peter