Evo Rear Caliper Refurb

[slogger]

I have never found Betas the most easiest of bikes to maintain brakes on, my sons Sherpa always seemed much easier ....  but I am hitting a problem with my 09 200 and wondered if anyone has hit the same problem or has any thoughts.

 

The rear started to show signs of being ineffective so I thought a full strip and service was needed. Taking the pots out and examining the seals showed significant wear so a refurb kit was purchased. After cleaning everything as I normally would do, the new seals and pots were refitted and one half went in OK whilst the other half would not move past the seal with reasonable pressure. Just to check it was not the seal grooves, I took the seal and pot set that went in easy, put them in the half of the caliper where I was having the problem and they fitted fine. The suspect pair went into the caliper half that previous was OK and they grabbed. Measuring the seals I noticed that the depth across the seal was not consistent and a wider than normal edge appears to extrude from the groove which looks like it is causing the piston to catch on one side.

 

I sent the refurb kit back and was sent a new pack which once again measuring them (before they had been exposed to any fluids etc) show the same manufacturing defect ie inconsistent measurements.

 

I have tried fitting these and whilst they went together, it was more than hard thumb pressure and once assembled, they are that tight that the master cylinder (which has also been refurb'd) will not get them to progress out to a sufficient depth, in fact when striping them this afternoon it took 45 mins with an airline to pop them out!

 

I have tried assembling with both DOT4 and also with rubber grease as an alternative.

 

I would appreciate any thoughts?