Also posted in B'world since we have no chassis-specific forums.

Something else for you all to worry about and check.

While on a road trip to Vermont last week, driving my 1983 300CD, my right front brake suddenly made a horrible screeching noise and locked up on an interstate exit ramp. I pulled into a parking lot and removed the wheel. The inside of the aluminum wheel had a shiny circumferential streak but I could see no corresponding bright spots on the adjacent steering or suspension points. I reinstalled the wheel and test drove in the parking lot. The brakes locked up going forward but released when backing. After a few test runs in the parking lot, the left front tire suddenly lost air. I removed the wheel again and installed my spare. Same noise.

I then drove very carefully, not using brakes, to a nearby general auto repair shop. We put the car on a lift and examined the front components carefully. Nothing immediately appeared to be wrong but we kept looking and finally noticed that one of the caliper bolts was completely missing. Apparently the caliper misaligned when braking and scraped the inside of the wheel. The sudden loss of air was caused by the caliper wearing completely through the inside of the wheel.

Luckily, the shop had a caliper bolt which we installed, checked the rest of them and I completed the round trip from home to Vermont without further incident, about 1200 miles total. The calipers were changed by me in February of 2012, about 30500 miles ago. This was a freak and a good reason for using thread-locker on those bolts.

Yup. Huge problem when novice mechanics use ANTISIEZE on those bolts!

Jay bob bought his 98 E300 and it made a noise when going from forward to reverse, I spotted the issue, removed his caliper bolts, cleaned out all traces of ANTISIEZE and I'm not sure if we used new caliper bolts with the proper Loctite coating or if I treated them with it...

But ANTISIEZE is NOT proper on brake bolts!

__________________
John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 560SL convertible
1987 190D 2.5-5SPEED!!!

1987 300TD
2005 Dodge Sprinter 2500 158"WB
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!

Thread locker on caliper bolts please!

Also spraying with the thread locker cleaning spray before the use of the thread locker is desirable if not absolutely necessary.

__________________
1992 W201 190E 1.8 171,000 km - Daily driver
1981 W123 300D ~ 100,000 miles / 160,000 km - project car stripped to the bone
1965 Land Rover Series 2a Station Wagon CIS recovery therapy!
1961 Volvo PV544 Bare metal rat rod-ish thing

I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior



Don't leave that there - I'll take it to bits!

Yes... a cleaned bolt with thread locker provides the same effect with regards to protection from corrosion that anti seize does... but keeps it in place at the same time..
When thread locker first came out it included a spray can of ' cleaner / activator ' for the liquid thread locker... a ' primer' ... that also encouraged clean bolts ...

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1980 240d ,

chain elongation, cam marks reference:
http://www.peachparts.com/shopforum/showthread.php?threadid=10414

http://www.peachparts.com/shopforum/diesel-discussion/305365-9-degrees-chain-stretch.html

evap fin cleaning:

http://www.peachparts.com/shopforum/showthread.php?t=156207&highlight=evaporator

A/C thread

http://www.peachparts.com/shopforum/diesel-discussion/297462-c-recommendations-mb-vehicles.html

Good post rocky racoon and all thats said is worth remembering Some of these bolts are very hadrd to torque up under the car without the proper tools .I had trouble with mine last year .Main thing is you have no room to get a torque in there ..So i locked them up as tight as i could with a large ring spanner .It was imposible to use a torque wrench as you dont have a lot of room to work .But i did use thread lock on the bolts .And i check them every year...

Question: I'm just finishing up the brakes on the 1991 560SEL. I'm using Permatex BLUE threadlocker. Should I be using Permatex GREEN??

I do not know the difference between those two colors..

UNLESS you are dealing with a really big bolt... like the single bolt on the back of a VW air cooled engine.. which takes a 200 lb torque to install...
I put RED locktite on all regular small bolts and nuts... it only adds about 5 ft lbs to the torque needed to undo them.. I started this when I had a Harley in the 1970's...
So I doubt there is any real difference in the blue or green thread locker performances... I would naturally go for the more powerful one myself..lol

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1980 240d ,

chain elongation, cam marks reference:
http://www.peachparts.com/shopforum/showthread.php?threadid=10414

http://www.peachparts.com/shopforum/diesel-discussion/305365-9-degrees-chain-stretch.html

evap fin cleaning:

http://www.peachparts.com/shopforum/showthread.php?t=156207&highlight=evaporator

A/C thread

http://www.peachparts.com/shopforum/diesel-discussion/297462-c-recommendations-mb-vehicles.html

True. Even if using the strongest version of LocTite (red I think) a modest application of heat from a torch will loosen it enough to remove the bolt.

The RED is labeled ' Stud and Bearing Mount' which scares a lot of people off.... but even without heat it does not make a normal size bolt or nut a problem...

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1980 240d ,

chain elongation, cam marks reference:
http://www.peachparts.com/shopforum/showthread.php?threadid=10414

http://www.peachparts.com/shopforum/diesel-discussion/305365-9-degrees-chain-stretch.html

evap fin cleaning:

http://www.peachparts.com/shopforum/showthread.php?t=156207&highlight=evaporator

A/C thread

http://www.peachparts.com/shopforum/diesel-discussion/297462-c-recommendations-mb-vehicles.html

This almost exact same thing happened not long after I bought my Mazda years ago.
Rear caliper top bolt had fallen out and disappeared, causing the caliper to tilt and hit and scrape against the inside of the rim.

Luckily no locked up wheel and the rim wasn't even damaged, but it could have been a disaster.

Exactly because of what Vtech said: previous owner used anti-seize when replacing pads.

I use blue loctite now. Last time I had to take the caliper bolts off I needed a cheater bar, but no torch, so I think blue loctite is perfect.

__________________
"The MB W123 is so bulletproof, you can drive them forever. Which is a good thing as it takes that long to get anywhere."
Betsie: 1984 W123 300D (hobby, 280k miles)
Myrla: 2001 Mazda Protege 2.0 ES 5spd (daily driver, 130k miles)
The Turd: 2007 Toyota Camry (wife's car, 118k miles)

Had a caliper bolt come loose myself, on a different car. I drove that car for 1,000 miles home when I bought it and had it for several years until one day... *ping* "What was that?" And then I tried to brake and immediately knew that the caliper was loose. Luckily we walked about a half-mile back and found the bolt. No idea why it came out.

My friend had the whole caliper come off on the interstate. That's quite a racket.

At least it's not the worst thing that can happen to a moving car (I think battery acid eating through the steering shaft takes the cake as far as things I've seen). Generally preventable though, I think.

-Rog

Yes, put a caliper back on an old accord without threadlocker. Caught it in city driving during the thunk-thunk stage where you could hear it move around.

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CC: NSA

All things are burning, know this and be released.

82 Benz 240 D, Kuan Yin
12 Ford Escape 4wd

You're four times

It's hard to

more likely to

concentrate on

have an accident

two things

when you're on

at the same time.

a cell phone.

www.kiva.org It's not like there's anything wrong with feeling good, is there?

There are a couple of different formulations for the green Loctite. The blue is fine, red is better but if for some reason you decide you must use the green then use the Loctite 290 formulation.

What you want:





What you DON'T want:


The 600 series stuff is some wicked, potent crap. It requires substantial heat to remove and can be a PITA to remove from threads. It is designed to permanently locate bearings and slip fit parts.

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“Whatever story you're telling, it will be more interesting if, at the end you add, "and then everything burst into flames.”
― Brian P. Cleary, You Oughta Know By Now