84 190D rear rotor lock nut removal, stumped - PeachParts Mercedes-Benz Forum

ah-kay · #1 12-06-2009, 02:16 PM

The parking brake is giving a scraping noise. Try to remove the rotor to inspect parking brake but cannot remove the lock nut. I am stumped. Help please.

Cannot remove the blue lock nut in the picture. I have pry out the pressed in lip already.

jt20 · #2 12-06-2009, 02:27 PM

you do not want to remove that large nut in the center.

the only thing you have to do is pull the rotor off after the caliper is removed

jt20 · #3 12-06-2009, 02:30 PM

you did release the parking brake, correct?

ah-kay · #4 12-06-2009, 03:21 PM

I have released the parking brake. Will try to pull the rotor off.

If I do not need to remove the lock nut then what is it for?

sasquatchgeoff · #5 12-06-2009, 04:15 PM

It holds the hub/wheel bearing/race on the axel - the rotor comes off by gently coaxing one side then the other. Spray some Kroil or PB blaster around the ring where the hub meets the rotor - should come off. Be careful not to get the oil on the braking surface of the rotor.

ds190 · #6 12-06-2009, 05:03 PM

Anybody want to mention the hex head disc retaining screw that he needs to remove from the rotor before it comes off ??

In his pic, it's to the right of the uppermost lug nut hole. I think it's 8mm allen wrench.

jt20 · #7 12-06-2009, 05:08 PM

^^not on the '84

thats just a placement tab.

....and it would be a 6mm

Billybob · #8 12-06-2009, 05:12 PM

With a flashlight looking thru one of the threaded wheel bolt holes you will need to line up a hole to access the parking brake's star adjuster wheel, then with a thin flat blade screwdriver pry the star adjuster turning it to shorten the adjuster mechanism's length thereby allowing the parking brake shoes to move closer together. With the shoes close together you should be able to get the lip in the brake drum's innner surface over the parking brake shoes.

ah-kay · #9 12-06-2009, 06:39 PM

I follow the instructions here and also the Haynes manual but I am still stumped. It looks like my rear axle is different.

1) I look through the holes and I do NOT see the "star wheel adjuster" to release the parking brake shoes.

2) There is NO hole that I can insert an allen key. The hole in the 1'o clock position of the picture is blocked with metal plate. Cannot insert anything.

3) I try to tap the rotor with a rubber mallet and it does not budge.

Anything I am missing?

jt20 · #10 12-06-2009, 06:46 PM

are you able to turn / move the rotor at all, by hand?

If you decide use more force, try banging in the bell, no the braking surfaces.

jt20 · #11 12-06-2009, 06:51 PM

especially since you are experiencing noises, it is most likely as BillyBob suggests. The brake shoes on the inside rotor surface are bound by a large ridge of metal / rust that prevent the rotor from coming off as they interfere.

the rotor comes off as you have it. You are probably going to want to replace it anyhow.... give it hell.

ah-kay · #12 12-06-2009, 06:59 PM

Quote:

Originally Posted by jt20

are you able to turn / move the rotor at all, by hand?

If you decide use more force, try banging in the bell, no the braking surfaces.

Thanks for the info. I can turn the rotor without problem. If I put it in gear ( manual tranny ) then the rotor will lock as expected. I will try to bang with more force. It does not turn out to be as straight forward as I have expected.

jt20 · #13 12-06-2009, 07:01 PM

Quote:

Originally Posted by ah-kay

It does not turn out to be as straight forward as I have expected.

familiar quotes entry.

If you can spin that rotor with the axle, then the brake shoes are not the main issue here.

give it a few more whacks.

good luck.

ah-kay · #14 12-06-2009, 07:06 PM

Gave it a big whack and it came off. Some brake hardware ( small spring ) are broken otherwise everything look OK.

Thanks for the BIG help.

jobah · #15 12-06-2009, 09:28 PM

The first time I did a parking brake replacement (circa 1989 on the same 190D i still have), I ended up using a sledge hammer....and it took several whacks!!

Glad it came off for you a bit easier.