Hi there
I recently decided to replace my hich dirty brake oil starting at the nearside or left side rear wheel. After bleeding the brake nipple using a gubsons ezie bleed kit I noticed the pads were worn down to 1-/8 th of an inch so I undid the two 7mm capiher pins and removed the 2 brake pads. Then I remembered to take the auto handbrake off so I put the ignition key in and pushed the small EBL lever down to see the dash parking brake go out and took the key out. So all well and good at this stage. Had to take a lip off the disc using a hand grinder to clean the disc up. Disc had rust on outer but non on inner surfa e like pad had been only acting on inner side
Then I tried several times to push the caliper piston back but couldn't. Bought a rewind tool but it doesn't seem to move the piston back.
Question Is my caliper piston seized or is there something I should do. How do I push the caliper piston back. Thinking to get someone to press on brake peddle to see if I can see the piston move with a piece of wood between the caliper to stop it popping out in error. This might free it up. Anyone encountered this problem on a X350 4.2. Measured two pin holes on face of piston think 18mm apart. Universal tool had larger spacing. What tool can I get. Do I need to get one from my Jaguar supplier with the right pin holes. What is 206-080 tool and is there on on ebay, please. Think need to retate piston and wind it back in,rather than just pushing on its surfave with a G clamp. Anyone help please.

 

Hello Ken,

Are you sure you're turning the rewind tool in the correct rotation (clockwise or counter clockwise). The tool comes with different threads for each side ? I can't remember which side is which but they are different rotation to rewind. Good luck.

 

Hi, Ken, what model and year do you have? The parking brake setups are different with the 04-05 supercharged cars. If you fall into that category I can post pictures and instructions.

 

X350 4.2 2007
Thank you for you replies folks.
Auto. To answer
I dont think I have a issue releasing the auto parking brake as it can be released by the manual EPB lever downwards which allowed both rear wheels to rotate when jacked up.

My main issue is moving back in the rear calipher piston back into the calipher housing. It seems jammed.

Might tried to push brake pedal down a bit to see if the rear caliper piston does move, but not too much without popping it out.

I ordered a unwind disc with 2 pins type tool with a nut to put a spanner on it hopefully the right pins about 18mm apart. ado I need to push it at the same time. Tried to push it by a G clamp/ value spring G clamp but it just bent the G clamp. So I gather I need to rotate the top of the piston first.

On which direction to rotate the unwind tool. Working on the nearside rear first. Does rotate back in clockwise or anticlockwise on the left hand side, nearside in UK if you know.

 

@KenXJ, here is link to the correct tool needed to reset the rear caliper pistons:

https://www.ebay.co.uk/itm/282988054...BlBMUOyI-_iDYQ

Here is a link to the X350 Workshop Manual:

https://www.dropbox.com/s/xl1qtf4hwt...anual.pdf?dl=0

 

For the caliper itself, some may require some gentle inward force while turning, especially if your piston has basically fully extended. I have seen this on several cars, where one side will simply retract by turning CW while the other side needed some low-pressure assistance to get it started while turning CW.

IIRC, The Electric brake cable requires a PDU or external "tool" switch to totally relax the emergency brake cable before performing the brake service. This is to disengage the mechanical force on the caliper and pads which would otherwise inhibit retracting the caliper piston. On reconnecting the battery, the cable will fully engage with the first engagement of the Parking Brake solenoid

 

I managed to buy a universal rewind set off eBay for £16. Had a magnetic RH and LH unwind d tool and various sized pins. Found sin the set mallest 19mm with 2 5mm pins fitted the 2007 X350. Part no is 106-081. Unwound caliper piston almost outside as wanted to unlink the hand brake cable and swap caliper entirely. My Vin H17352.

Now how to unlink handbrake cable. Tried usual put car out of park or push EPB down to get light to go on the dash but this only moved handbrake a minor mm or so. Will 1 look under car to see how handbrake is routed incase I can loosen a clip. Other plan is take boots module connector off, and jump a wire from Red and White to baytery -ve and Green and White to battery +ve to see if can get the handbrake motor to reverse and release the handbrake cable near the caliper.