Tip for parking brake springs - PeachParts Mercedes-Benz Forum

mumbles · #1 04-01-2009, 06:18 PM

I just replaced the parking brake cables on my 81 300SD and have these tips for un-/re-installing these supposedly difficult springs for the parking brake shoes. Instead of buying the special MB tool, I used a flathead screwdriver (thin enough to fit through a hole in the hub, wide enough to not slip into the spring) and a vise-grip, and once I figured this out taking the springs out took about 10 seconds, and reinstalling took about 30 seconds. This is just a tip for removing/installing the springs and I assume you already know how to assemble the other components.

The bottom spring has little clearance but had no problem wiggling it back in. It does go in one way which appears to be the larger of the 2 hooks towards the front of the car. With the small end of the spring in place, I just used vise-grips to pull the larger hook into the slot, and popped it into place. Doing this before the center springs helped to hold the shoes in place while working on the other springs.

For the center springs, I did the one that is towards the front of the car first. What you do is you put the spring through the slot in the parking shoe, and line up the spring with the slot behind the parking shoe that it's supposed to go into. Then line up a hole in the hub with the spring. The parking shoes will flex to give you some access to get some light in there to see what you are doing. Then you put the screwdriver through the hole in the hub and set it into the spring so that it is flush with the bend in the wire (which goes back through the coil and becomes the hook) and with just enough pressure to hold it in place. Make sure you don't turn the spring while doing this otherwise you'll be off your mark. Then you clamp your vise-grips onto the flat part of the screwdriver head and flush with the spring. You may want to double check that everything is lined up before trying to push the spring in by flexing the parking brake shoes towards you again and lining it up once you have the tools in place. The idea is to use the vise-grip/screwdriver combo to push the spring straight into the slot, and then twist it into place. Make sure to turn it so that the screwdriver is pushing on the bend in the wire. That's how you get your turning power. Also make sure you push it in all of the way before you turn. I gave it a 90 degree turn and it sat fine. Once on, give your parking shoes a good shake to make sure the spring is holding properly and install the second spring.

The second one might be a little harder to see if it's lined up because the first spring is holding the shoes in place, but with the shoes half installed it will kinda naturally want to line up anyways. Plus you'll already have a feel for the process so it should be that much easier.

To uninstall the springs just reverse the process. It might take a couple of tries to figure out how much to turn it.

I hope this helps some folks and would appreciate any feedback, suggestions, or comments. I could probably post some pictures in the next couple of days if that would help people. Cheers!

~bri

PS ~ Oh yeah, and if anyone knows why it took me 4 hours to install the rear left parking brake cable and about 15 minutes to do the right , I'd love to find out what I was doing wrong. I didn't want to disconnect the front cable, so maybe that was it but that actually seems more problematic than what I ended up doing. I don't know if this is a safety issue, but if I had to do this again, I would buy 2 right side cables and take up the slack in the y-harness.

winmutt · #2 04-01-2009, 07:11 PM

I have had pads on the shelf for years now, the FSM is mind boggling complex in its description. Thanks for the tip!

Simpler=Better · #3 04-01-2009, 07:19 PM

Brake shoes are a PITA to replace, no matter the scale or brand

mumbles · #4 04-01-2009, 08:25 PM

I had read that these are a really tough job, but once I got a good look at them, I had no reservations about taking them apart. Plus I had to to get to the brake cable end. Also, note the orientation of the star nut when you take things apart (it's three parts, a slotted bolt, a star nut, and a "cup"), and install the top spring first before the shoes are on. That'll hold the starnut in place more or less. Drop me a line if you have any questions.

~bri

pawoSD · #5 04-01-2009, 08:37 PM

I just did this on my W124 last week, its a pain, that is for SURE! I ended up getting the hole in the shoe and the hole in the wheel assembly lined up, then I took needle nose pliers, grabbed the shaft of the spring, shoved it in and turned, and voila....all set. This took several tries on all of them though. Getting the old ones off was no big deal, two of them had sheared off and lodged themselves against the shoe......and the others were rusted and broke off when I pulled at them.

Both sides were also missing the big heavy spring on the opposite side of the adjuster....no wonder the brakes dragged/would not release/and didn't work!

Simpler=Better · #6 04-01-2009, 09:09 PM

Only do one side at a time, so you can reference the other side.

nickofoxford · #7 04-01-2009, 09:11 PM

Wish my parking brake worked on both sides

Im going to give this a shot, thanks for taking the time to share that!

280EZRider · #8 04-01-2009, 11:09 PM

I can't imagine having a great need to change the shoes unless you drive around with park brake on. I've yet to change mine, but if I do, I'd like to know if it isn't the same as changing the shoes on any old drum-brake car (back brakes). When I was a kid 2 centuries ago, these were the only brakes we worked on.

charmalu · #9 04-02-2009, 01:28 AM

Yeah, these parking brake shoes are basically the same thing, just a pain to work on because they are behind the axle hub after the rotor is off.

Charlie