hi,

My offside front brake sticks and scrapes the disc. Resistance while driving and burning.

Driving along the steering wheel started shaking while accelerating to around 55 mph, I noticed a lot of resistance. I stopped to check and the front drivers side brake was really hot and smelt of burning.

Being close to home i drove back, jacked the car up and turned the wheel, it sounded like scraping but very minimal resistance while turning, so took the caliper out to give it a clean and inspect the piston seal, everything looked ok so assembled it back and took it for a test drive. Hard, progressive, emergency braking and everything seamed as it should with no noticeable resistance and no hotter than the other brake.

Out again a day later accelerating to around 50-60 mph and 10 miles into my journey it starts scraping again.

Would a caliper rebuild kit solve it? or any other suggestions would be appreciated.
Code number JLM 2191 is what I've found for the kit.

XK8 1997 convertible standard calipers.

Much appreciated.

 

If you do not have Brembo brakes, you have a sliding calipers.
If the outside pad is hot or excessively worn check the sliders are free of corrosion, properly lubed and slide freely. This most likely your problem.
If the inside pad is hot or excessively worn then you have a sticking caliper piston. As long as it's not leaking, working it back and forth might free it up, but if this is the case a proper repair would be either rebuild the caliper or replace it.
Regards,

 

No Brembos.
I think i'll take the other side off to compare, thanks for the reply.

 

+1

In our damp UK climate the Guide Pins (item 5) often get patches of surface rust which can make the caliper stick.


(click on the image to enlarge it)

If this is the cause of your problem, the Guide Pins can be usually cleaned up with fine 'Wet & Dry' and lubricated with a minimal coating of Coppaslip.

Graham

 

This might be helpful .............

caliper rebuild.docx

 

Found a split i missed last time.


This was before cleaning, so I just sprayed it and rubbed with a rag and copper greased. now sliding smooth.

 

Its probably the caliper but another thing to consider.....

Brake flexi hose, the rubber can collapse internally and not allow the brake pressure to be released when you remove your foot from the pedal.

Also although a different system, there are many threads about when changing the pads to open the bleed nipple rather than force the fluid back up into the brake system which can cause problems. Your pads look quite new, has your fault appeared since a brake pad replacement ?

 

I've found the parts online using the part numbers from the guide, Thank you very much!

The braking system has not been touched for around 4000 miles, so I don't believe its the cause, but the pads have taken a beating over the last few drives.
Good point about the lines, think i'll do them too as they are reaching 18 years old now.

Hi,

I done the push pull test with the pads out, it was a little stiff, I took the guide pins out and gave them a little clean. They easily slide back and forth now with little effort.
Thanks for the suggestion.


I'll keep this updated, unfortunately the 2nd year of uni is starting soon and I need a hefty deposit for a new flat.

 

Just wondering.

Prior to 2001, I owned a M20 Mooney aircraft for 13 years and being a certified aircraft mechanic, did all the maintenance myself, unless the task was beyond my abilities, and changing the brake pads was a normal routine.

Here's where my question comes from. After replacing the brake pads, it was common practice to take the aircraft out to the taxiway and with the towers Ok, would fast taxi holding the brake pedal down a little, then stop as hard as possible. After doing that two or three times you could feel the difference in stopping power. I referred to this task as "running the pads in". Some called it "Burning the pads in" . Either way it seemed to work.

I read where some folks complain that stopping power is lacking somewhat after replacing their old pads with 'Ceramic Pads'. So my question is, has anyone tried this airplane technique and "run their pads in" ? I bet it would work.

Cheers

 

Chuck,
Good point. This should be standard practice, and is called burnishing the pads, or bedding the brakes. Several brisk applications slowing from 50 to 20mph, being careful not to overheat or burn the pads.
Afterwards it would not unusual to see light smoke coming from the pads, and I mean LIGHT.
Regards,

 

A nice video for you guys to watch if you haven't seen it already.