Could one change Brembo Front callipers piston dust cover in situ?

[Submariner1]

Discovered a small hole in one dust cover. MB do sell them #A0014210986 (£12 for others who have C216s), but they do not sell a piston seal kit.
Hence I need to ensure water does not corrode the piston or its a whole new calliper! £224
Bought them

Picture from the calliper side

Re Question is one Brembo refurbisher says you can fit them in situ without removing the calliper.
Do you think this is possible?
He said just squeeze them in at the edge, and then when you push the piston back they just go in :-0
Do you reckon he is right?
You only have real access from the back i.e. This side.

From the front there is a bar that gets in the way


This is the access with the pad removed

You can just about get ones finger 2/3 to the back, plus no idea how hard one has to push to get it in, or does it possibly go over a protruding lip?
Anyone done one of these?

Close up


And it would Be exceeding difficult to get to the back edge of the dust cover to push it into a groove or over a lip, as that bar stops access from the other side.

Side view of the new one
As it would sit againt the calliper wall


I had hoped to drive the car to an Indy, to fit new pads, yes I know its simple but would rather have the peace of mind its done right.

The issue is if I pull off the split dust cover, will I be able to get the new one pressed in (or over any lip that may be there)?.
Plus one is kinda limited to see how well one has cleaned up the rear of the dust cover groove without taking off the calliper.

This dust cover feels like its got a metal backing inside the side that goes into? The calliper groove, or does it go over a lip, or maybe just sits up against the calliper side Wall (I doubt the latter, re water ingress ).

It would save a whole load of driving if I could do it. And then get the Indy to fit the pads and confirm its all done properly.

My worry is , I get it off, or partly off, and due to lack of access cant get the new one on :-/
Then I would have to take the whole calliper off ... a tad above my comfort zone!

If I got stuck do you reckon I could you drive 70 miles to the indy with the dust cover just "placed" over the calliper?

Any opinions much appreciated, as the pad is out and the wheel off ... all outside crap.

Note my caution is MB do not sell the actual Piston seal, they say that is a new calliper. Hence my desire to ensure the piston is preserved at all costs.

The damage is new ... i.e. One week, effing wheel refurbisher stuck a screw driver into the calliper (trying to push the brake pad against the rotor, to stop the wheel rotating, rather than lowering the car a little! ) at the time I wondered what he was doing
Until he called a mate who opened the door and pressed the brake pedal! Course ai cant prove he did the damage! And All the others are fine!

 

[KennyN]

Three options :

Smear a small amount of silicone sealer over the damaged rubber and forget about it.

Take the car to a mechanic who will remove the caliper and fit a new outer seal to the caliper

Split the caliper in situ , which will knacker your paint, and fit a new seals to the caliper yourself then bleed the brakes.

The groove , in the caliper, that the outer part of the seal fits into will need to be completely free from debris to locate the seal properly so the only way to do that will be option 2 or 3 listed above.

Kenny

 

[John Laidlaw]

Confused- if you were going to an indy (MBS presumably?) to get the pads fitted why don't you just do a silicone sealer smear for the short term, drive there and get it all done?
Suspect I'm not reading your post closely enough, I have a short attention span

 

[KennyN]

PS - Just for the record, the pins that go through the caliper to hold the pads look a little too short. I changed my pads last week on the CLS and they protruded around 4 -5mm through the hole.

Just make sure they are fully "home" at the back.

Kenny

 

[Submariner1]

Confused- if you were going to an indy (MBS presumably?) to get the pads fitted why don't you just do a silicone sealer smear for the short term, drive there and get it all done?
Suspect I'm not reading your post closely enough, I have a short attention span

Hadnt though of the silicone sealer, sods law the split is the other side, difficUlt to get at.

Injust thought I would ask, as ai was told it would be doable.
But I see Kennys point one needs to get the chanel totally clean.

 

[Submariner1]

Three options :

Smear a small amount of silicone sealer over the damaged rubber and forget about it.

Take the car to a mechanic who will remove the caliper and fit a new outer seal to the caliper

Split the caliper in situ , which will knacker your paint, and fit a new seals to the caliper yourself then bleed the brakes.

The groove , in the caliper, that the outer part of the seal fits into will need to be completely free from debris to locate the seal properly so the only way to do that will be option 2 or 3 listed above.

Kenny

Thanks Kenny
Looks like option 2 if I can get some silocone sealer on it. You can see it but as its at
THe back very difficult to get to.

Looks like option two is a best for me situation.

 

[Submariner1]

PS - Just for the record, the pins that go through the caliper to hold the pads look a little too short. I changed my pads last week on the CLS and they protruded around 4 -5mm through the hole.

Just make sure they are fully "home" at the back.

Kenny

Hi Kenny
They are fully home at the back.
Are they the right ones ?

I dont remember my SL500 s protruding .. bit didnt really look as it was a new car.
But thanks Imwill ask the Indy to check it.

 

[om613]

No.
You have to remove the caliper to clean and seat the seal properly.
I did them on my 123 some time ago. Not that easy, on the bench, as they are an interference fit and require pushing in with evenly distributed force.

 

[Submariner1]

No.
You have to remove the caliper to clean and seat the seal properly.
I did them on my 123 some time ago. Not that easy, on the bench, as they are an interference fit and require pushing in with evenly distributed force.

Thanks so much, there is nothing like the experience of having done a job.
- So my suspicions were right.

Q1. Out of interest could it be done with the caliper suspended i.e. With the brake pipe connected?
Appreciate thats not as easy as having it on a bench.

Just thinking as the discs are lipped, all the hassle to remove a caliper, should I bite the bullet on the discs now. I have new pads but sort of seems a waste not to have new discs. (Sigh more £sss )

It looks like its just 3 bolts to undo the caliper. Personally detaching the caliper and brake fluid line is further than I would want to go.

Q2. Did your dust seals, come out easily?. I would Hate to slip and scratch the piston! As they dont sell them or the seals.

Q3. On mine you can see a little crude/corrosion between the tip of the piston and the dust cover (circa 5mm) . Did you push the dust cover back and clean that up before removing the dust cover to keep the Piston and seal clean.?

Q4. When you say it requires an evenly distributed force to push it in, which I totally get. Did you take out the piston and lay a flat surface on it, or have a plate with a 49mm hole in it for the 48mm diam piston to poke through? or just
Do it manually all around as evenly as possible.

Note I am only being paranoid about this as one can not buy the piston or the real piston seal.

I guess its quite tricky getting the dust boot over the piston end , as when you press my pistons they go into the calliper pretty easily, i.e. You cant just push them on, or hopefully the pistons will stop before fully retracting.

 

[om613]

Thanks so much, there is nothing like the experience of having done a job.
- So my suspicions were right.

Q1. Out of interest could it be done with the caliper suspended i.e. With the brake pipe connected?
Appreciate thats not as easy as having it on a bench.

Just thinking as the discs are lipped, all the hassle to remove a caliper, should I bite the bullet on the discs now. I have new pads but sort of seems a waste not to have new discs. (Sigh more £sss )

It looks like its just 3 bolts to undo the caliper. Personally detaching the caliper and brake fluid line is further than I would want to go.

Q2. Did your dust seals, come out easily?. I would Hate to slip and scratch the piston! As they dont sell them or the seals.

Q3. On mine you can see a little crude/corrosion between the tip of the piston and the dust cover (circa 5mm) . Did you push the dust cover back and clean that up before removing the dust cover to keep the Piston and seal clean.?

Q4. When you say it requires an evenly distributed force to push it in, which I totally get. Did you take out the piston and lay a flat surface on it, or have a plate with a 49mm hole in it for the 48mm diam piston to poke through? or just
Do it manually all around as evenly as possible.

Note I am only being paranoid about this as one can not buy the piston or the real piston seal.

I guess its quite tricky getting the dust boot over the piston end , as when you press my pistons they go into the calliper pretty easily, i.e. You cant just push them on, or hopefully the pistons will stop before fully retracting.

1. I wouldn't try that. If you've gone that far, take the lot off and just be resigned to bleeding the brake.

2. Yes but levering out with a screwdriver, distorting the metal backing. No worries, as what's nearby isn't the piston sealing area.

3. You could do that (as per 2). I was stripping and rebuilding the whole caliper anyway.

4. Not sure. I think I put the seal on the piston, fitted the piston, then pressed the seal home with something flat on either side, then push the piston fully home.

 

[Submariner1]

1. I wouldn't try that. If you've gone that far, take the lot off and just be resigned to bleeding the brake.

2. Yes but levering out with a screwdriver, distorting the metal backing. No worries, as what's nearby isn't the piston sealing area.

3. You could do that (as per 2). I was stripping and rebuilding the whole caliper anyway.

4. Not sure. I think I put the seal on the piston, fitted the piston, then pressed the seal home with something flat on either side, then push the piston fully home.

Thanks really appreciate the detailed reply.

I would normally undo the brake line and rebleed as done on the AClass, but when I had the brake fluid changed my IndY said this car needed to be pressure bled ... not sure whatnthat is but guess one needs some kit!