I was suffering with knee problems at the time I bought my 90 and it got to the point it was almost impossible for me to drive, so I fitted a servo. I used a Lockheed LE72696. I measured the pedal force required before and after fitting - it was reduced from 25lbs to 14lbs, which was about the same as my wife's Audi A2 that she owned at the time.
Here are a couple of pics of the installation.
I did have trouble trying to get all of the air out of the hydraulic system after I fitted it, but a Gunson Eezibleed kit soon sorted it out. It then worked reliably for the 7 years I owned the vehicle.
I was suffering with knee problems at the time I bought my 90 and it got to the point it was almost impossible for me to drive, so I fitted a servo. I used a Lockheed LE72696. I measured the pedal force required before and after fitting - it was reduced from 25lbs to 14lbs, which was about the same as my wife's Audi A2 that she owned at the time. Here are a couple of pics of the installation. I did have trouble trying to get all of the air out of the hydraulic system after I fitted it, but a Gunson Eezibleed kit soon sorted it out. It then worked reliably for the 7 years I owned the vehicle.