Morning all.

First the facts.

I replaced all rotors and pads a couple weeks ago.

I was not able to get the parking brake cable back on due to not enough slack in the cable.

The parking brake lever on both calipers appears to be functioning, the cable moves freely.

I seem to be feeling a little brake drag on the rear wheels, and when i first drive the car i can hear the rotors touching the pads...the sound disappears shortly.

Now here is the question... is it possible i did not rewind the pistons far enough? I was able to get the calipers back on the new rotors, but it was a bit tight.

Is it worth my time to take the calipers back off and try to rewind the pistons a little more?
Thanks

 

do you mean rewind as in you had to use a caliper spreader tool or a c-clamp to get the piston in the caliper back to fit in the new pads? If so, then it doesn't matter. The c-clamp or caliper spreader is simply used to fit the pads and caliper back over the new rotor. Where you spread the pistons to doesn't set where they will always go back to because the minute you hit the brake pedal, the pistons will push the pads together and will keep them there. I had the same issue that you had with the parking brake cable. Try this though. Right under the parking brake lever in the car on the underside of the car should be an adjuster and a splitter bar. You can adjust the amount of slack that your parking brake cable gets and it'll make it easier to re-install your parking brake. Personally, my adjuster is rusted and I can't really adjust mine so I just used force to get my parking brake cable on and had it drag for a couple weeks.

 

iownme, yes, you can pull the rear calipers off and wind the pistons in a little more.

As for the e-brake lever, first off, make sure that your e-brake handle is all the way down. After you wind in the pistons some, you will find that you will have enough room to pull the e-brake lever forward to put the end of the cable in. Worst case, get yourself some good pliers and you should be able to pull the cable tight enough as you push the e-brake lever forward to get the cable in place.

 

No he meant rewind the pistons. X type rear caliper pistons do not compress, do this and destroy a piston. they have a special tool to screw them back in. That said it is possible you did not screw them in far enough but then you would have had a hard time getting the calipers remounted.

 

Howdy,
I would like to know more about the special retraction tool you mention...
Does anyone have any References or Pics ??

Cheers,

 

I think he's referring to the second post in this thread.
https://www.jaguarforums.com/forum/x...y-pushy-20371/

 

sorry for causing the confusion!...but we are talking Jaguar...lol

The rear pistons do not just compress like the usual pistons. You need to apply a lot of downward force while turning the piston with the "cube" tool. I'm not sure if it can even be done without the tool.

This is the 2nd set of pads i've installed so only just "not my first rodeo :+)"

When i turned the pistons i could turn them only far enough to just be able to get the caliper back on, and it was tight.

Not knowing the internal workings of the rear calipers and parking brake assembly is what made me question whether trying again to turn to pistons would be worthwhile or a waste of time.

I'm now imagining that as one turns the piston, that will move the parking brake lever on the back of the caliper move forward, and as i did not rewind my piston completely, my park brake lever is too far back to allow me to return the park brake cable back into its holder....how does this sound to you?

The proof will be in the pudding !....i hope to get to it today

 

I bought tool (clickable link). The cube thingie is cheap and easy enough, but having ended up with it stabbed in my palm a few times, a few skinned knuckles, etc - I just decided to get the right tool.

$35 USD, and it seems like an adequate tool. Build, materials and fit seems fine. Plus, enough goodies to fit just about any other vehicle, too

Haven't used it yet, is too cold to do until Springtime now - garage is unheated.

 

I posted this a few weeks back

https://www.jaguarforums.com/forum/s...344#post628344

 

Hey Bruce,
Thank you.... it looks like a comprehensive kit you have obtained.

Good Luck with it, do let us know how well it works for you (in Spring)

Cheers,

 

The cube is really easy to use. Get a good C clamp, tighten it up, and use a screw driver to turn it in. Both sides turn forwards the front.

 

You had difficulty turning the pistons in because you need to just crack open the bleeder screws which will then allow a little pressure and brake fluid to escape. You don't need to open the bleeder very much to get the job done.
Also the brake piston cube tool is available at any auto parts house or Sears or Harbour Freight store etc. for around $10. The compression tool is not needed for the rear brakes but is needed for the front on these cars.

 

I have not needed to crack the bleed valve before...I just removed the cap from the brake fluid reservoir....if that doesn't work this time I,ll try cracking the bleed valve

 

The reason cracking the bleeder screw works so well is that it gives relief right at the caliper, plus there's no chance of brake fluid getting some where you don't want it. You don't need to open them very much, just enough to allow some seepage.

 

Just remember one turns left hand the other right hand to go in.

 

I see the verb "rewind" and think WTH?
Its a rotary compensator.
Honda used a similar device on the timing chain adjuster for the CBR series bikes.
Kind of insidious on those motorcycles, because the rotary action was dampened, and the viscous fluid used often "hardened" with time. So an unsuspecting DIYer would remove the adjuster, set it down, and while they were not looking, it would slowly extend. Then when they replaced the adjuster, it now a couple of milimeters longer, it would put undo tension on the chain and prematurely break it.

 

Hi Bruce..im glad you displayed the item you say works to retract the piston.

I too have this tool..i borrowed it from autozone but im having difficulty using it and would like to know how you were able to use it.

I was using both the E & F adapters with the push assembly and back plate..i held the 22mm hex screw while trying to turn counterclockwise (rear driver side - i heard it is supposed to be counterclockwise and rear passenger is clockwise)

However following all directions i still was unable to retract the piston. I even tried a smaller adapter (i think G) and still no results.

Could it be that my caliper is permanently stuck or im not using this tool right??

Also..when i removed the pads..they were stuck to the caliper..they did not rest on the caliper carrier (which i imagine is where they are supposed to be housed). I was concerned because i had to use a rubber mallet to remove the pads from the caliper because it was clamped to the piston.

Any help is really appreciated!!

 

droid, when winding in the rear calipers, open the vent port on the calipers and then try doing the pistons. A lot of people have found that unless you are the Hulk, you will not be able to push in the pistons unless you open the bleed port. Then they will go in really easy. Just be ready to catch a little bit of fluid.

As for the pads being stuck to the calipers, it is possible that someone glued the pads. This is done to minimize the chance of any pad noise. I do it to my car all the time. Granted, the stuff I use isn't that hard to remove, unlike what you are experiencing.

 

Thanks Thermo..you are always always so helpful in your guidance..I will try your recommendation as soon as this blizzard lets up.


I'm just concerned that my caliper is completely shot because the rotors were paper thin!!..and my best guess was that the piston was permanently stuck..which I hope that is not the case.


But I never tried opening the bleed port and I will try that next. However, can this cause air to be introduced into the brake lines and will I have to add brake fluid after I'm done?

 

Droid, 2 things with the condition that you are in:

1) because the rotors were so thin, it may be that the piston got unwound too far and it has actually come "unscrewed" (if you ever take a caliper apart, you will get what I am saying with this, but there is a screw mechanism which is what you are rewinding in this case). So, you may need to make sure that you push the piston back on square so you can mate the threads back up and get it properly rewound.

2) yes, most likely you will need to bleed the rear brakes after you are done to make sure that you get all the air out of the caliper. But, this is pretty easy to do. All I do is get some tygon tubing (9/32" inside diameter as I recall) and run it from the bleed port to the top of the wheel well and back to a glass container on the ground. You can then open the port, pump the brakes a few times to get a standing column of fluid in the tubing. Add some more fluid to the brake reservoir, pump it a few more times till you see the fluid change color. This will garantee you have new fluid in the caliper (maximizes life) and that your caliper if full of fluid with no air in it. You then can close the bleed port and move on to the next wheel.

The big thing with the bleeding of the brakes is making sure that you don't drain the fluid reservoir. I normally pump the brakes 4-5 times before I add more. Having a second person with you when you do this can be helpful.