When to replace the Rotors

[02sahara]

On 8/5/2024 at 8:53 PM, Son of Marty said:

It sounds like a caliper problem, When you replaced the pads did all the pistons retracted easily?

Nah ... not easily. Had to use some leveraged force ...

 

On 8/5/2024 at 9:01 PM, Stevenc22 said:

unbolt the caliper on the bad side and see if the rotor spins freely. If it doesn't, it might be wheel bearing problems. If it does, then you probably have a caliper issue.

Ahm ... can the caliper be unbolt without removing the break lines / replacing brake fluid at that point?

[Stevenc22]

26 minutes ago, 02sahara said:

Nah ... not easily. Had to use some leveraged force ...

 

Ahm ... can the caliper be unbolt without removing the break lines / replacing brake fluid at that point?

 

Of course it can. Two bolts hold the caliper to the knuckle. Remove them and lift caliper off rotor but do not disconnect the brake line.

[Son of Marty]

Don't let the caliper hang on the hoses, I usually hang them off the hard lines with a wire tie or bent coat hanger. 

[02sahara]

 

Well ... the rotor spins freely (it just doesn't spin numerous rounds when giving it a spin, but I guess that's normal?!).

 

Rotor also doesn't seem to be warped when inspecting it with caliper off.

 

Guess I'm gonna either get a rebuilt caliper or do the tii upgrade. Need to think about it.

[Stevenc22]

Did you inspect the rubber brake line. If its old it will swell up internally and put pressure on the caliper pistons and rotor.

['76mintgrün'02]

The test(s) I mentioned above will tell you if the problem is in the brake hose(s).

 

2 hours ago, 02sahara said:

Guess I'm gonna either get a rebuilt caliper or...

 

I'd suggest replacing the pair, if you go that route.  Symmetry is good, when it comes to brakes.

 

 

 

[02sahara]

Alright, some new insights:

- Brake hoses look fine on the outside.

- Brake hoses seem to be the original ones  There is a ring on them saying 04/76. I would definitely replace them with the next service I now need to do regarding the brake issue.

- Did the brake hoses test as mentioned by you: But the brakes are still dragging and the fluid comes out regularly. So it's not the hoses?!

- Also, when I had the caliper off the rotor, lines attached, and the reservoir open, when trying to push the pistons back in, they immediately bounced back when releasing the mechanical push back pressure. In my head this seems like the internally restricted hose, but you know better ...

 

 

One thing initially forgot to mention is this – that was one reason why I thought it's clearly the rotor ... maybe that leads you to other options(?):

 

On 8/5/2024 at 8:24 PM, 02sahara said:

During breaking the car stumbles; noticeable at low speeds immediately before coming to a halt.

 

Guess I just need to replace/rebuild calipers and hoses anyway now as it's not clearly the rotor or the hoses ...

[Stevenc22]

If the pistons spring back, its likely the hoses. When hoses collapse internally they tend to let fluid flow one direction but not the other direction. Change all the hoses before doing anything else.