Had this problem last year when I bought the car so I ordered pads and discs from Britishparts. That got rid of the issue but now 5000km later ,its back.

Any suggestions? Lubricate the calipers or just buy new ones? I've tried some hard braking but no difference. The strange thing is that sometimes I almost don't feel it at all. And on the next touch of the pedal it pulsates heavily.

 

....Electrohydrolic valve inside anti - skid going wacko , any anti - skid fault codes ? Is the anti- skid off or on ? Sometimes air in the lines causes this and is a least intrusive try . At least on airliners . Someone suggested a better way to bleed the lines I saw a month go but can't recall now . Now I remember is to hold the bleeder hoses up in a U shape and not down as this later method allows air to be able suck back in as you pump the brakes during air bleeding process . Leaking bleed valves ?

 

Cheap discs don't last. I've had a set from an Indian manufacturer less than 3k and they're pulsating like mad. Check run out with a dial gauge. If not that, back to the ABS

 

Assuming anti - skid was on , is this symptom of of ABS code C1095 ? With the bad soldier of the servo power point on the board . Rotor dial out can probably done for free as a shop's estimate .

 

One other possibility, depending on the type of pads you have, is uneven friction material transfer.

Here's a very brief article. Tons more out there.

https://www.dba.com.au/tech-article-...rial-deposits/


Cheers
DD

 

Okay thanks that's interesting. Was thinking about upgrading to ebc next time. Did a lot of bleeding when I installed last time and used that U trick as well with the hose. I always felt that the brake pedal was soft but so many said it's supposed to be like that so I never bothered investigating further. It passed its MOT . I have a feeling that one caliper might be bad though.

 

The rears are smaller , SC engined might be bigger all around , inspect cylinder well for condition , if chromed clean with MEK based cleaner like carburetor cleaner if it has MEK , if not chromed polish with buffing compound to remove binding varnish

https://www.jaguarclassicparts.com/uk/part/JLM12123


https://www.jaguarclassicparts.com/uk/part/JLM20671