The left rear caliper is leaking brake fluid pretty badly. I've never done any brake work myself before, so I'm curious to get the forum's thoughts on the level of difficulty of replacing the caliper by a first-timer if I order a rebuilt Bendix from Phil.

Back in June (state inspection time), my indy put on new pads, rotors, and flex lines, so I'm hoping things aren't too corroded and stuck in place.

I've reviewed both of these write-ups:
PeachPartsWiki: Front Brake Pad & Rotor Replacement and
PeachPartsWiki: Replacing the Rear Brake Pads & Rotors (I realize this is for the W126)

Any recommendations? If I decide to go to a shop, are the MB brakes "general" enough that any competent mechanic can do them? (My MB indy is a good 45 minutes away, but I use another local guy for my other cars and he does good work.)

Thanks, all.

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05 E320 CDI - 185K miles
82 300D - 200K miles (sold)

Have you identified the exact source of the leak?

The bottom third of the caliper on the inside is wet, but the fitting where the flexible line connects is dry. Is there a possible leak source that would suggest a replacement is not needed? Would removal of the caliper be required to check fully? (Totally out of my element here, sorry for the simplicity of my approach!)

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05 E320 CDI - 185K miles
82 300D - 200K miles (sold)

The only thing practical in your stuation is a rebuilt caliper. Any other choice will make the time charge at the garage built up. Makes sure you buy one for the leaking side. They are different on each side. There may be two brands though ATE and bendix. Unless you want to change both sides get the same manufactures one for the replacement. Both brands bolt up.

Any mechanic should have no difficulty changing out a brake caliper. It is far from rocket science. There is absolutly no reason to drive all the way to a brand specific shop for this issue.

I guess the only other leak possibility for examination would be a loose bleeder screw to bleed the caliper. I have never seen one self loosen up yet. In fact locally it is hard to even get them loose at all because of the rusting. Without a torch it is not going to happen here in fact in most cases.

NH82,

I just did my '83 rear calipers and hoses. I am nowhere close to the experts on this board, but I did this straight forward repair/replacement. I replaced both, but only one was siezed.

I replaced the hoses as one was plugged solid. Yours appear newer, but I know not when yours were last replaced.

Bleeding the brakes with my son at the helm was no problem.

Best of luck with your repair, Remember your life depends on this repair, so you must assess your capabilities. (Disclaimer !!)

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Gary
Experience is something you get, Just after you needed it....
'99 E300 295K, '83 300D 220K, '75 240D 185K sold
'80 MCI Bus Conv DD 6V92TA, w/4 cyl. Kubota diesel GenSet 12.5KW

Everyone else knows!!!

" Busted"

No excuse, tired & pooped, listening to my wife......

thanks TF

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Gary
Experience is something you get, Just after you needed it....
'99 E300 295K, '83 300D 220K, '75 240D 185K sold
'80 MCI Bus Conv DD 6V92TA, w/4 cyl. Kubota diesel GenSet 12.5KW

You said you ordered a rebuilt Bendix rear Caliper.

Are your old rear Calipers Bendix or ATE Calipers?

I reused the Bolts that attach the Brake Calipers to the Car (I put blue Loctite on the threads).
But, Mercedes Service Manual recommends replacing them with new Bolts.

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84 300D, 82 Volvo 244Gl Diesel

Do we know the PN for the bolts front and rear? Smart things to know/have handy...

No, I havent looked in fastlane to see if they are listed.

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Current Diesels:
1981 240D (73K)
1982 300CD (169k)
1985 190D (169k)
1991 350SD (116k)
1991 350SD (206k)
1991 300D (228k)
1996 Dodge Ram CTD (442k)
1996 Dodge Ram CTD (267k)

Past Diesels:
1983 300D (228K), 1985 300D (233K), 1993 300D 2.5T (338k), 1993 300SD (291k)

The symptoms you have described are typical of a failed piston seal which I have experienced several times in the last 30 years. This can present as either as a slow leak or can drain your reservoir overnight without prior warning! In your case it would appear to be the latter. The seal requires flexibility and resilience as it is crushed against the piston to half its width every time you apply brake (see below). The seal hardens and wears with age and a cold winter can be the last straw, the seal either pulls away from the piston or breaks when brake is released and out pours the fluid.

All that is required to fix the problem is to fit a new seal kit (10-15$) provided that the hard chrome on the pistons is undamaged and the outer face of the seal groove is not corroded. Removal of just the bake pads should be enough confirm whether piston seal is leaking.

As you indicate that you are not happy to tackle the job yourself your options are to remove the calipers (do both!) yourself and take to a reputable mechanic to fit a new seal kit or buy replacements. You don't want a learning curve when working on brakes.

Keep in mind that a so called "Rebuilt" caliper is nothing more than a 25 year old caliper with a new seal kit fitted and a coat of paint so compare prices carefully!

Good luck!

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Beagle

I'd recommend buying the rebuilt instead of a seal kit. Assuming the brake work was competent and the mechanic tightened everything but didn't strip anything you could speculate that pushing the piston back in to fit the new pads damaged the seal. If the seal was damaged by this, maybe that means it's got corrosion on the chrome piston.

The cost difference isn't that large compared to the labor to repeat the job and down-time if the piston is damaged and the caliper can't be rebuilt.

Standard advice is to replace calipers in pairs, but as long as you're matching the caliper on the axle your braking should not be affected. If you ordered from Phil, he may have discussed this and ensured you got the right parts.

Inspect the pads to make sure they're not getting saturated with leaking fluid.

Your tread wear also looks uneven. You may want to look into your alignment and suspension at some point and budget for those repairs.

I haven't ordered anything just yet. I believe I currently have Bendix calipers as they have the little clips on the end of the retaining pins for the pads. I should probably discuss with Phil to confirm.

I checked for the new caliper bolts and, oddly, the catalog only lists ones for the front:

PeachParts FastLane Mercedes Parts Store

Another question for Phil...

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05 E320 CDI - 185K miles
82 300D - 200K miles (sold)

I agree it does look uneven in the photo, but the tread is actually in fine shape. No doubt the car is due for an alignment and probably some fresh suspension components but (for now) that tire is doing OK.

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05 E320 CDI - 185K miles
82 300D - 200K miles (sold)