Removing old brake caliper 300TD wagon - PeachParts Mercedes-Benz Forum

mdesmarais14 · #1 10-09-2008, 10:33 PM

I have a rear brake caliper on my 1985 300TD wagon that was sticking and getting real hot. I was able to detach the brake line, then broke the bleeder screw that was very rusted, and after some light tapping with a hammer, and jimmying with a screwdriver, I was able to free the seized pistons and get the old brake pads out. Then I tried to remove the 2 large bolts that hold the caliper on (if I'm correct) and they were not moving for anything. This is likely the original caliper. Any thoughts or tricks on how to remove the old caliper so I can put a new on in? This is my first experience with brake work.

lutzTD · #2 10-09-2008, 11:06 PM

breaker bar and a little umph. just make sure you are on solid ground with jackstands and try not to be too far under the car, even better if you can get the breaker bar level with the ground and far enough out to get a foot on it, if you have a good breaker bar put a pipe on it too, make sure you are turning it the correct way since its in the back and not facing you

jt20 · #3 10-09-2008, 11:26 PM

heat is often very helpful in the 'large rusty bolt' situations. Get the caliper body (not the bolt) really hot as fast as you can. Then try to break the bolt free.

others might recommend spraying the bolt with PB blaster a day or two before attempting w/ the breaker bar. (I agree w/ lutz^^^)

t walgamuth · #4 10-10-2008, 05:43 AM

I have always been able to get them off wo heat, just a half inch breaker with a pipe extender.

t walgamuth · #5 10-10-2008, 05:46 AM

BTW, if you are getting a different caliper to install on your wagon the rear calipers have slightly larger pistons but use the same pads as a sedan, so they carry a different part number.

mdesmarais14 · #6 10-10-2008, 11:15 AM

thanks for the info, I will give it a try with a breaker bar tonight, I was just using a regular socket before, will try the heat too if need be.... hope I can fit the breaker bar in there, it is kind of tight quarters...

vstech · #7 10-10-2008, 11:31 AM

you can do it just fine with a regular 1/2" ratchet. you just need a hammer to hit the wrench with.
Oh, and IF some moron's put the bolts back on with red or green loctite... if they did, you will need heat.

mdesmarais14 · #8 10-10-2008, 12:35 PM

I was trying the hammer hitting the ratchet approach last night, no luck. I assume since the bolts are not facing me I need to hit the ratchet down which should loosen the bolt, is that correct?

lutzTD · #9 10-10-2008, 12:43 PM

Quote:

Originally Posted by mdesmarais14

I was trying the hammer hitting the ratchet approach last night, no luck. I assume since the bolts are not facing me I need to hit the ratchet down which should loosen the bolt, is that correct?

best way to be 100% sure is set the ratchet direction in your hand, then put it on the bolt. I have to do this sometimes when I am under the car reaching up to a bolt. once you know which way to turn, I still suggest a breaker bar instead of a ratchet and hammer

vstech · #10 10-10-2008, 12:43 PM

that should be the correct direction. are you using a 6 point socket? and a good 20Oz or larger hammer should do it. you may need to get an impact wrench. if hitting the ratchet with a hammer does not loosen it, you're going to need heat. some idiots really do put them back on with red loctite. you have to heat the backing plate up to 500°F to soften the red.... Good luck.

Chad300tdt · #11 10-10-2008, 12:47 PM

I use an 18" breaker bar with an impact socket and a 3 lb. hammer to loosen the caliper bolts.

Remember that when looking at the bolt head from the top you go counter-clockwise to loosen. When you're loosening the caliper bolts (from the side of the car) you're looking at the bolt from the bottom, so you go clockwise to loosen them.

mdesmarais14 · #12 10-10-2008, 01:00 PM

ok, got it.. I will try the breaker bar tonight after work... hopefully I will not need the heat.

pizzachef · #13 10-10-2008, 01:26 PM

Mine had blue loctite, they were really hard to turn, but came off with a lot of exertion on my part.

Do these bolts really need loctite?

Chad300tdt · #14 10-10-2008, 01:31 PM

I wouldn't trust them to stay put without blue loctite. Same with the bolts that hold the front rotors to the hubs.

mdesmarais14 · #15 10-10-2008, 01:49 PM

the calipers on mine appear original, would they have loctite? or are they just fused and rusted after 23 years