I’m looking for technical help or recommendations on: possibly sticking caliper
I recently replaced the front left caliper on my mk3.5 as the old one was sticking (had a mechanic confirm)
After replacing, it is still noticeably harder to spin the wheel on that side, and get much hotter after a drive. I bled the caliper after installing. I replaced the slide pins, and I greased the pan shims/slider plate things.
I have new pads and discs, but I don’t want to install them if they are going to be burned through quickly again!
Any and all advice welcome, and happy to provide further info or pictures if needed.
Love Japex! They are actually the ones who diagnosed the caliper initially and did my alignment! If i cannot get this solved this week, I was planning on booking an appointment with them for the brakes and a few other bits.
Would be unusual for a brand new caliper to exhibit exactly the same issue as the one you took off. Could it not be a knackered wheel bearing that’s causing the increased friction and excess heat?
Or possibly the part of the disc you can’t see (the rear) is worn, rusty more than that side you can see.
I’ve experienced it with another car a few years ago. The dealer fitted new pads and sent me on my way, 2 weeks later I was getting noise upon braking and an hot disc on one side, the backs of both discs were disintegrating with rust. Extreme, yes but it cost me another set of pads and obviously new discs that time.
Hi,
jack both front wheels of the ground & get someone to press the brake pedal hard, try & rotate each front wheel to see if equal pressure is being applied to both brakes.Release pedal & see if both wheels rotate as freely as each other.If not gently release bleed nipple on side which is sticking, if fluid squirts out & wheel frees off you have a flexible brake hose which has collapsed internally.
Also make sure that both discs are OK & that pads are not sticking in their slides as a sticking pad can soon create a lot of heat which will magnify the problem .
The fluid did seem to shoot out more on the left side than the right, so I replaced the hose, only to find myself right back at square one. I have to assume the pads are sticking or not releasing properly? I am now looking to order new brake fitting kits, just in case that is what the issue is.
If that doesn’t work, I think I have to give it to the pros.
What lube did you use on the slide pins ?
Did the piston retract enough so that the caliper moves easily side to side when assembled with pads ? ( Before you have pressed the pedal to re-seat the pads to the disc )
One other thought - without the caliper fitted - do the pads move fairly easily across the fitting shims in the carrier ?
I have known some pads to jam slightly in the carrier and need minor filing to move easily.
Exactly the symptoms of a stuck caliper when I had on a Swift Sport back in '17.
One wheel with much more brake dust (and to be sure, after just washing them and going for a drive), and one wheel much hotter when you put your hand by it.
Garage said stuck caliper, so had a new caliper, rear pads and a brake fluid change. Fine after that.
When you replace a caliper you don’t fix issues with sliders. The sliders form part of the carrier. Unless you were supplied both components you still could have an issue with the carrier, guides and pins. I normally renew the stainless inserts that carry the pads but before that throughly clean and scrape out any rusty deposits otherwise the pads can be a tight fit and get stuck.
By sliders do you mean the pins that go into the bracket that holds the caliper?
I did replace those, and cleaned the slots/tubes that they go into thoroughly, so they slide freely now.
I also TRIED to clean the metal plates that the pads sit on, and put some copper ease on them, but I am now thinking maybe I didn’t do a good enough job. Today I am going to clean those again, fully push the caliper back into the housing (I have the proper tool), and try swapping the pads around just to see if they slide more freely on one side than the other.
It’s more the cast slots in the carrier that the stainless shims fit into. If they have heavy rust deposits on them the shims don’t fit properly. Not necessarily what your issue is but good practice at preventing issues.
