Brake Caliper Rebuild?? or New ones - PeachParts Mercedes-Benz Forum

356nen · #1 01-14-2007, 01:06 AM

Hey Guys,

I was doing a routine front brake pad replacement on my 83 300D when I ran into some problems. I could not push in one of the pistons in to insert the pad. I have done this in the past and have never had a problem. I usually get by with using the old pad and a couple of C-Clamps to push the piston in. One piston I could push in by hand but the other I could not get to push in. I tried opening the bleen valve thinking I can push it in and force the fluid out but it did not work. I ended up removing the caliper but still could not move the piston once it was on the bench. Does anyone have any insite on this problem, has it happened to them? Can I rebuild the piston or do I have to buy a new one? Can I get a use one?

Thanks,
Rene

Ara T. · #2 01-14-2007, 01:47 AM

You can rebuild them as long as the piston bores aren't rusted and corroded. I could have rebuilt mine but opted to not bother and just get rebuilt calipers. Still got my old ones sitting around somewhere.

yellit · #3 01-14-2007, 01:49 AM

You may can save it if the bore and piston are not too pitted up from corrosion....use some pb blaster or such to get it loose after you remove the boot to let the juice get down in there..... let it soak a while...work it up and down slowly with plenty of pb blaster when you get it moving to avoid scoring.....I have used compressed air but be careful to secure the other piston and put a thick piece of wood in between the pistons to catch the stuck one when it comes shooting out....keep the fingers away.... Mine had some pitting on the one that was stuck but it was way down in there so I just cleaned it up and got bore and piston slicked up with very fine emory paper.....cleaned the threads of the line port and the bleed screw...then flushed good with alcohol and dried.... Next new seals and boot kits on them and they work fine now...I think I painted them with engine enamel after all the work....It takes some time and effort so if you are in a hurry just get new or rebuilt units.....Just do not take the caliper halves apart to service your old ones...Good idea to change the fluid again after driving a while to get anything that was left flushed out.....brake fluid is cheap.....I still have the back ones to do on my 240D....then on to all 4 wheels on the 1978 300D....hope this helps...

thorsen · #4 01-14-2007, 08:26 AM

As a general rule, I rebuild them when they leak fluid and replace them when they are frozen.

Lately, however, I have been replacing them. Most of the rebuilt units carry a lifetime warranty.

leathermang · #5 01-14-2007, 11:33 AM

All things considered.... with due consideration of the costs and the safety issues....
I would replace now while remanufactured units are still available ( and warranty is a bonus)... we can't count on that situation being the same 5 or 10 years from now...then you would have those ' fresh' ones to rebuild at that time....

gatorblue92 · #6 01-14-2007, 08:43 PM

i would get new ones... i never mess around when it comes to brakes... better safe than sorry

biobenz617 · #7 01-16-2007, 11:08 AM

If rebuilding...what about taking apart the caliper halves to replace seals between? I noticed this is advised against in the factory shop manual because the torque values are "unknown." Seems like that should be considered also when rebuilding a 20+ yr old part. My haynes manual for my Landcruiser shows this procedure. Does Cardone do this?

Stevo · #8 01-16-2007, 11:17 AM

Quote:

Originally Posted by leathermang

All things considered.... with due consideration of the costs and the safety issues....
I would replace now while remanufactured units are still available ( and warranty is a bonus)... we can't count on that situation being the same 5 or 10 years from now...then you would have those ' fresh' ones to rebuild at that time....

I agree. I get "loaded" rebuilts from my local "West Bay" parts store, never had a problem over the years. They need to know if they are Bendex or ATE.

sailor15015 · #9 01-16-2007, 11:51 AM

I was successful in rebuilding the rear calipers on the bimmer. They had a little bit of corrosion on them from brake fluid that obviously hadn't been changed in a while. I used compressed air with a block of wood in the caliper to get the pistons out. I think a rebuild kit was somewhere around $30 from my local part house. Emery cloth got the corrosion off the pistons, per my indy's suggestion. All in all, it was a pretty easy job. The deciding factor for me was that new calipers were about $230 a piece and could only be special ordered from Germany, needing 4-6 weeks to get here!

SirNik84 · #10 01-16-2007, 04:33 PM

I just rebuilt calipers. grabed a set from pick'n'pull for 20 per caliper, and got the rebuilt kit from Phil and Fastlane for 10 per caliper. took them to school and sandblasted the calipers, then washed them to make sure the sand was out. i let them sit for a night to dry. then i used break assembly lube to lube up the caliper in all ther areas the fluid will go. then lubed the pistons and the caliper bores. and put them together. they didn't just slid togehter, but they were pretty easy. i them painted them black with caliper paint. i masked off the pistons to keep the paint away from the seals.

so for:
$20 per caliper
$10 per caliper kit
$6 for caliper paint
and some assembly lube i got from school (free)

i got a new set of calipers for less then $70

and at $90 per caliper from napa. i think that was worth the 3 hours i spent working on them... but i only make $15 an hour. so it might be worth it to some of you to just buy the calipers.

diesel don · #11 01-16-2007, 06:14 PM

I've done both.

I agree with the compressed air method, with the block of wood inbetween. Start with low PSI and build from there.

I was able to remove some light corrosion without scarring the surface and they've worked fine since.

However, I did it as an adventure. Generally, I just buy rebuilds.

Diesel Don