ok

tom w

__________________
[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

Do you think Sears...would have a nice 9mm torque wrench, or a more proper tool for loosening the bleed bolts? They are alot closer to me than HF is.

AA

__________________
'87 924S
'81 280SEL

Sold ->

81 300SD -
93 300E w/ 3.2
85 300D-
79 300SD
82 300CD
83 300CD - CA
87 190E 5 spd
87 Porsche 924S

"..I'll take a simple "C" to "G" and feel brand new about it..."

The torque wrench is probably overkill. And, it's doubtful that Sears would have 1/4" drive, anyway.

I'd still recommend that you get that propane torch and heat outside the screw (on the caliper) for about three minutes. Your odds of snapping the screw just diminished by about 50%.

Look at all I missed from going to the cottage yesterday. The torque wrench is not a good ideal on bleeder screws if rust is present as you have no way of calculating how much of the screw has been reduced with rust. Therefore even if you had a valid torque range that screw may have become very substandard. As stated earlier it is a climatic thing as well. Just ask some people where you live if the bleeders always back out without major assistance. Easily done. As one gentleman stated they are no trouble at all in california for example. Now where I live I heat the casting in bleeder screw area with ox/ace until it is red. Douse with a soaking wet cloth. Do this three times and the screw almost comes out with bare fingers.. Also using my method even if there was not enough material left to take any removal torque and it lets go you do not need extractors etc as the threaded portion is loose already and pretty easy to get out. But we do have so much corrosion. After the first time I loosen the screws I always put a good dab of very heavy waterproof grease on them after reinstalling them so they will hopefully not rust again. Quality of the bleeder screw design is also a factor. Example: volkswagon bleeder screws have very little metal in crossectional plane below the hex area you apply pressure to as well as being hollow. They are not very strong really even when new. I also do not use a wrench but always a six point deep socket to try to reduce the side force component as much as possible when application of pressure plus less chance of rounding off the hex or breaking off. I can only re state I know where you live has nowhere close to the corrosion we have. A little heat is usually a good thing even if it is just from a propane torch as some have suggested. It does increase your chances of success by reducing the amount of pressure required.

What about the issue of boiling brake fluid? If that casting is red hot, this must occur. Do you find that it backs up into the master and overflows it?

Strange as it seems this does not occur. My own personal fear used to be damage to the piston rubber. I think it is the intense local application of heat that does not allow enough time to let the heat travel very far in the casting that lets this work. In practice the casting goes dull red perhaps 3/8 inch out from the bleeder screw. It is important to really cool it as quick as possible to achive maximum effect. I also fully realise a good disk brake fluid will boil at 450F and suspect if not fresh at a slightly lower temperature. One other major consideration is the proximity of the rubber break line. It is just common sense to not get it hot. Here in the canadian maritimes Probably 50% or more of working mechanics have settled on this particular method. I am not a working mechanic by the way. All other attempted measures seem to result in replacement calipers all too often. This is almost a foolproof method. But again we are in a pretty bad rustbelt around here and would not expect to have to use this method in florida. Even here it probably only applies to cars that are perhaps more than five years old that have not had the bleeders moved since new. Changing brake fluid yearly has not caught on big time yet but have never seen a downside to it myself. Believe it lessens more major failure and is cost effective. One more point. Doing the proceedure three times seems to destroy all the oxide bond between the threads so the fitting is quite loose after the proceedure. If done properly the friction between the bleeder srew and caliper threads will require just the lightest / moderate pressure to start backing out. Twice is not enough and four times is overkill. One of those things you have to see to believe.

Thanks for the valuable info. I might try that next time I get a difficult one. Never figured you could safely apply so much heat without any damage.

Brian, every proffession has its trade secrets. Real practicing mechanics have a multitude of things I am sure to make their job a litttle easier. The last point I will clarify is do not use say a cutting head . I just use a small/medium welding tip torch. It builds localized heat rapidly. Remember I am also trying not to remove the temper from the bleeder screw during the process. So do not let the hot point in the flame play on the bleeder screw itself. Most people are well aware if you heat up something once it helps. Heating and rapidly totally cooling several times moves it into another dimension. I believe it is fracturing the oxide in there perhaps just reducing it to powder by the extreme movements occuring. I wonder If hunter would mention how he tackles difficult or badly rusted bleeders as I think he practices in a bit of a rustbelt himself. Also suspect he lurks around here more than we know.

I'm sure he has a pile of trade secrets that he has not divulged on here. He's big on the generalities but, the actual tricks of the trade seem to be closely guarded..........

OK Barry..and BC;

Thanks for all the tips.
I am in Florida and my 300D does have rust although I don't see any near the calipers or screws.
Q: When you say; "I heat the casting in bleeder screw area with ox/ace..."

What part is the casting?
and What is an Ox /ace?

__________________
'87 924S
'81 280SEL

Sold ->

81 300SD -
93 300E w/ 3.2
85 300D-
79 300SD
82 300CD
83 300CD - CA
87 190E 5 spd
87 Porsche 924S

"..I'll take a simple "C" to "G" and feel brand new about it..."

The casting is the mass of metal the bleeder screws into. The oxygen and acytelene are the gasses mixed in a torch to produce a very hot and intense controlled flame. We have to depend on them quite a lot when working on cars in the rust belt. Not so in your area. What you call rust is probably next to nothing in comparison to northern rust. Hit those screws with a good penatrating oil for a few days prior to loosening them will probably be okay in your location. Perhaps thats not even required. I kind of stold your thread when I commented and elaborated about loosening the bleeder screws, sorry.

Well thanks. I may just heat them up a bit prior to greasing them.
(Sorry to hear about your rust.)
But to grease them up for a few days prior, don't I have to keep taking all 4 tires off each day to grease them??? That's a PITA!

__________________
'87 924S
'81 280SEL

Sold ->

81 300SD -
93 300E w/ 3.2
85 300D-
79 300SD
82 300CD
83 300CD - CA
87 190E 5 spd
87 Porsche 924S

"..I'll take a simple "C" to "G" and feel brand new about it..."

Remember, you're not using grease. You need PB Blaster or Kroil, both of which come in spray cans. You can get underneath the vehicle and spray the bleeder without removing the wheel if you know where they are.

I think you are getting nervous from all the replies here and overthinking things. PB Blast the thing and go to Kragen and get a pack of Alltrade metric combination wrenches, goes from 17mm to 6mm I believe and will cost you 10 dollars. The wrench you will use to crack your bleeder open is 3 inches long at the most... if you break it using a tiny wrench like that then you would have broken it with anything.

__________________
1985 CA 300D Turbo , 213K mi

spray and wiggle carefully.

tom w

__________________
[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.