1994 E320 wagon driver side caliper top bolt stuck issue - PeachParts Mercedes-Benz Forum

dmorgan · #1 09-21-2016, 07:18 PM

I am trying to remove the caliper on my 1994 E320 wagon driver side. There are two bolts holding the caliper to the rotor. I was abled to removed the bottom caliper bolt using 3/4 inch six point socket and breaker bar with little difficulty due to more leverage and more space to work with. When I removed the bolt, I notice blue coloring on the end of bolt thread about 1/4 inch long. it must be locite for tightening bolt threads. When trying to remove the top bolt on the caliper, this is were I am having some problems. Using the same setup as above 3/4 inch six point socket and breaker bar, the caliper top bolt won't move. I had just finished replacing all the other three rotors and brake pads on the other three wheels myself and now come to only one bolt left to remove. I tried using PB Blaster on the bolt. I even tried to push the breaker bar using both feet standing up going down, even the wheel was turned all the way to the right so I have some more room and leverage to work with, barely. That is one tough bolt and still won't bulge. The driver's side front wheel is on one jack stand leaving very little leverage and room to work with from the bottom of the asphalt floor. I tried smaller ratchets and going under the wheel and still no luck. The breaker bar is too long to manuever any leverage left I have while trying to remove the bolt inside and under the wheel with limited space. It seems I need more space and leverage to remove the only bolt left. It sure baffles me, because I was able to do the other three calipers with little difficultly in removing caliper bolts. Also, there is very little space between the bolt on the caliper and wheel joint (if that is what is called), because using the socket and adapter and breaker bar takes up some room with limited space to manuever when trying to remove the bolt.
I read some articles about removing caliper bolts and it seems that using a propane torch or some other stuff to produce heat on the darn bolt head and hopefully ease up the threads to make it easy to remove the bolt . I am very hesitate using the propane blow torch because I never use one before and concerns about getting some other areas around the brake system on fire by accident due to limited leverage and space around the caliper.

It seems to me the best and safest option is put back together the old brake pads, rotor, and drive the mercedes wagon to the shop. The mechanic in the shop will be using the vehicle lift and whatever tools necessary to remove that stuck bolt and then replacing old brake pads and the rotor with new pads and rotor.(my replacements parts I bought rotor and brake pads) The mechanic is just doing the labor and nothing else. I feel by going this route will cost me extra bucks when I could have done this myself and defeat the purpose of do it youself. Any comments and/or feedback is greatly appreciated.

duxthe1 · #2 09-21-2016, 08:22 PM

Its not uncommon for techs to use an impact to tighten those bolts instead of torqueing them. Heat will soften up the Loctite and you only need be careful of the brake hose and abs sensor harness. If you can get a wrench on it and give it a few whacks with a hammer it'll probably break loose. I've literally used an alternator as a hammer for that exact purpose in the junkyard.

dmorgan · #3 09-21-2016, 08:55 PM

duxthe1

Thanks for your above comments. I just wish there is some other way besides using propane torch to heat the tightened bolt. Also, I had been using the breaker bar and the hammer. I gave quite a few whacks with no success so far.

duxthe1 · #4 09-21-2016, 10:55 PM

Socket on a bar doesn't transfer impact force very well. Find a wrench.

dieseldiehard · #5 09-22-2016, 12:17 AM

In a pinch for heat on a stuck bolt I've used an electric heat gun, they make them for industrial purposes and they throw a small diameter blast of hot air that will in about a minute or so heat a nut and loosen the locktite. Some electricians use them for heat shrink tubing for insulation maybe you can borrow one?

optimusprime · #6 09-22-2016, 06:43 AM

DMORGAN Do you have a small bottle jack .I had the same problem removing mine. You need the best ring spanner you have thats had no wear .Place bottle jack on the floor put the spanner on the bolt and use the bottle jack to break the bolt open..It wioked great for me, after 2 hours playing with it. Let us know if it works

Hirnbeiss · #7 09-22-2016, 07:29 AM

I would use a torch without much worry - just keep it focused on the bolt head. Remember brakes see high temps all the time. Also, consider a longer breaker bar.

Ferdman · #8 09-22-2016, 08:41 AM

dmorgan, recommend jacking the car higher so there is more clearance to work. Use a cheater pipe over the breaker bar handle to increase the torque. Make sure the socket stays square to the bolt head so you don't round it off. You may also try removing the caliper bracket with the caliper attached, then work on the stuck caliper bolt with the bracket in a vice. That way you could use an impact tool to loosen the bolt.

A bottle jack would help on the passenger side caliper bolts, but on the driver's side the breaker bar handle needs to turn toward the floor.

Zulfiqar · #9 09-22-2016, 10:03 AM

I have always been successful with a wrench and heavy hammer for such bolts. Using a socket wont cut it as it flexes on the square drive joint, a wrench beam is more rigid when struck with a hammer.

I also have a few large offset box wrenches for axle nuts of FWD cars, havent met a nut that could put up a fight with those.

optimusprime · #10 09-23-2016, 05:03 AM

Well i told you what to do ,only way i could get mine open was with the bottle jack .

chazola · #11 09-23-2016, 07:07 AM

Longer breaker bar and all my weight has always worked for me, never let those bolts beat you!

dmorgan · #12 09-23-2016, 02:48 PM

Today I went to the store to check out this electric heat gun. I was intrigued by this electric heat gun. Maximum temperature is around 1000 F. I was told that the heat temperature maximum of 1000 F is not hot enough to generate heat down to the thread. So I barely let go and not buying this electric heat gun with reservations. Next I got the 3/4 inch enclosed wrench and a 2.5 lb sledge hammer as a backup. When I got home, I went to work on that stubborn bolt. Barely enough room for the enclosed wrench to get on the bolt. However, I had some more room to play along with little leverage to turn the bolt clockwise facing me. With a strong pull toward me using my hands on the wrench, the bolt finally moved!!! I did not expect that at all. I was truly surprised by this!! I thinked it has something to do with JB Blaster and the thing about that is I left JB Blaster soaked through the head bolt overnite. In any event, upon looking at the top bolt with six points, five of them were stripped. In comparison with the earlier bolt that I had removed, the other bolt had only one stripped point. Must be lucky for me. I am going to replace those two caliper bolts with new ones, to be safe. Now I can cancel the trip to the shop!! Thanks guys for all your feedback, comments in this post. You guys rock!!