Use blue thread locking compound on the caliper bolts.

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Current fleet
2006 E320 CDI
1992 300D - 5speed manual swapped

former members
1984 300D "Blues Mobile"

1978 300CD "El Toro"

Sounds like you have uncoated rotors - follow Frank's and Brembo's advice to remove the light oil film.

You need a dial indicator to check run-out. Not a dial caliper

Lot's of links on net on how to use and you can buy a cheap and adequate one at HF. You also need the magnetic base that they sell separately.

https://www.youtube.com/watch?v=6SbWB2CNqio

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Graham
85 300D,72 350SL, 98 E320, Outback 2.5

If you buy high quality rotors you shouldn't need to check the run out with a dial indicator. Out of the box they should be true and straight. If they are not, return them immediately and buy genuine MB rotors.

Typically you get what you pay for. You cannot purchase a MB vehicle for the cost of a VW.

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Fred Hoelzle

Hopefully the Brembos he has are of good quality.

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1990 190E 3.0L

They should be! Besides, run out is not only to do with rotor quality. It is also affected by installation. Cleaning up the hub surfaces, properly torqueing stud bolts, wheel bearings, etc.

Shops don't often check runout, but it is so cheap and easy to do, why not!

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Graham
85 300D,72 350SL, 98 E320, Outback 2.5

I've removed the top and bottom pins, how do I remove the retainer spring itself? I noticed a small bolt that appears to be holding the horizontal middle section of the spring on the left side of the caliper (see photo).

Also, you can see the bolt on the left at 1:30 on this video. Do I need to loosen that bolt?

https://www.youtube.com/watch?v=9vbJX1MLrWY

Attached Thumbnails

 

With the 2 pins punched out the spring clip has to come out by itself, might just need a light tap due to the rust.

Manually spread the top end of the calipers or pry up on the spring. It's loose already.

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1990 190E 3.0L

OK, the retainer spring came out (yeah!!!). I then loosened the nut on the metal brake line and placed a golf tea in the end of the metal brake line to prevent leakage. The calipers appear to be pressed against the brake pads making removal of the brake pads difficult. Any ideas??

"How do I remove front disc retainer springs?" That is the pad retainer.

It is stuck between the pads, because the pads are completely worn out, and the tops of the backing plates have been forced against the retainer spring by the pistons, which are stuck in the caliper bores, preventing their retraction.
Get a prying tool under the spring, use excessive force, and pop it out.

I'm thinking if I remove the caliper from the rotor I could more easily remove the brake pads......is this idea feasable? Again, the calipers appear to be pressing against the brake pads making their removal difficult. I have tried wedging a pry bar between the brake pad and the caliper to press the caliper back into its bore but am unable to get it wedged in.

Yes.

And it is the pistons that are against the pads.

Got it, sorry, when I'm tired I sometimes misname or mistype.

I'm using a 1/2" drive 19mm socket and a long breaker bar on the bolts holding the brake caliper. I've sprayed PB Blaster on the bolts holding the caliper. The bolts won't budge!

So...I've sprayed them again with PB Blaster and am going to let them sit for 15 minutes or so. I sure hope I don't need an impact wrench for these 19mm bolts!!! I also saw a youtube video where the guy uses an oxygen acetylene torch to loosen stuck bolts.

They have threadlocker on them. A little heat will help soften that. I used one of those small pencil butane torches to heat the bolt head and that helped. Can't really recall, but I think I have used a piece of pipe to get extra leverage on some brake jobs. (maybe impact gun on others - but is there access)

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Graham
85 300D,72 350SL, 98 E320, Outback 2.5