Confusion about hub/rotor removal - PeachParts Mercedes-Benz Forum

JWJ · #1 03-31-2007, 10:09 PM

I need to replace the driver's side front brake disk on my '85 300TD (wagon).

I read a few posts here that lead me to believe that just a big hammer was required to remove the hub/rotor.

But the factory manual I have suggests removing the hub cap and then loosening a hex screw. It has pictures of exotic tools that look expensive. I see no way of removing the hub cap without these exotic tools.

I removed the tire and caliper. I banged on the rotor with a hammer with no success. The rotor appears rusted to the hub. Wouldn't these come off as one piece if rusted together? The hub will not budge. It feels like something else is holding the hub.

Am I missing something?

Thanks in advance,

Larry Delor · #2 03-31-2007, 10:28 PM

Take off the actual hub cap, undo the locknut on the watchmacallit, unscrew said watchmacallit, take out the bearing, and pull off the hub.
Look on the backside of the hub. You will note 6 (if I remember right) hex bolts - you will want to remove those, before you can remove the disc from the hub. It takes a little ooomph - a vice would help.

Don't forget to pack the bearing.

techguy512 · #3 03-31-2007, 10:32 PM

Yes, you're missing something.

The rotor is attached to the hub with 5-6 (can't remember) hex head screws. The
problem is that the hub and wheel bearings need to be undone in order to access the
hex screws, which are behind the hub.

Don't just hammer on it, expecting the rotor to come off.

t walgamuth · #4 04-01-2007, 12:12 AM

it is six allen bolts.

after you get them out (you will need an allen in a socket and a half inch breaker bar with a 6" extension to get them out).

they are right tough to break loose. and when you reinstall you want to use some red locktite too.

let us know if you need help getting the hub off. do you have a repair manual? these things are downright simple to work on most of the time if you have a repair manual.

good luck

tom w

RAYMOND485 · #5 04-01-2007, 12:40 AM

1984 300d Turbo
Install The Tire Back On The Wheel And Hold The Tire On The Floor
Next To A Wall It Will Not Turn And Use A Allen 2 Ft Ext To Break
The Allen Bolts The Rotor Torque To 80 Pounds Install The Bolts With Blue Lock Sealent

JWJ · #6 04-01-2007, 12:53 AM

Thanks!

How do I remove the hub cap?

My repair manual shows using a special MB tool.

300SD81 · #7 04-01-2007, 01:25 AM

I used a universal 3 arm puller, and pulled with my hand, (do not use the screw in the puller!)

crashone · #8 04-01-2007, 02:21 AM

Use a soft mallet, place a short, stout flat blade screwdriver in the groove, gently tap,(you have to hold the screwdriver at an angle towards the outside), rotate, tap again, when you see the cap moving from the hub place screwdriver in crack and gently tap, rotate and so on until the cap comes off. You will see the locknut with a 6mm allen bolt, loosen it, unscrew the nut, the bearing will be behind it. That small piece of metal thing that is sticking out of the end comes out, put it back when you reassemble, that is for noise suppression. You know the rest....

Larry Delor · #9 04-01-2007, 02:44 AM

Might want to mentally note how much spin/friction you have now - so that when you put the locking nut back on the spindle, you don't have your hub/wheel too loose or too tight.

Shorebilly · #10 04-01-2007, 06:25 AM

The Allen (socket head) bolts require a 10mm Allen socket......

.....and do not over grease the hub......

also, you should do brake rotors in pairs......

Actually, I don't know exactly how to comment here, and not hurt someone's feelings......but the brake rotors are a "sort of" a self evident and simple job....if you are at an early point in your automotive mechanical hobby....it's a good idea to clean and repack your wheel bearings when doing this job.....it's also a good idea to replace the inner bearing seals......but if you choose NOT to remove the inner bearing then you must be very careful NOT to get any dirt into the wheel hub.....a couple of clean rags should be inserted in either side to prevent foreign stuff from entering......

Re-bolting the hub to the wheel is a good tip.....it helps....

don't hang your calipers by the brake lines......make a little wire hook....or use some wire ties to hang the calipers.....

clean everything.....and clean your greasy fingerprints off of the disc.....ose brake cleaner.....and if you add grease.....use wheel bearing grease formulated for disc brakes......plain old EP-2 will not do......

Good Luck......

SB

JWJ · #11 04-01-2007, 12:10 PM

Quote:

Originally Posted by Shorebilly

if you are at an early point in your automotive mechanical hobby

Yes, you have very nicely stated the obvious limits to my present mechanical ability. I'm a computer engineer by trade - so if it involved 1s and 0s I would understand it better. But the lack of electronics is part of the reason I bought the cars...

Thanks everyone!