13 replies to this topic

[mrducati]

My bolts on my caliper is rusted stuck. Will a heat gun help it loose? And where do I target the heat, on the bolts or on the body of the caliper. My common sense says that if I target the bolt it will ekspand and thereby get more stuck, but it feels somehow unnatural to heat the entire caliper. Anyone with a bit more experience please advice!

Mini Cooper 1998 MPI

[MGBailey007]

if you heat it up yor run the risk of melting the seals in the caliper try soaking then im penetrating fluid

[L400RAS]

What are you using to undo them? I haven't been beaten yet with just a simple 3/8" drive 12" breaker bar and 9/16" socket.

I wouldn't put heat near the rubber brake hoses, or the caliper containing flamable brake fuid

[samsfern]

A heat gun wouldnt do anything. A good quality 6sided socket an decent length bar should shift them.

[Cooperman]

As Sam and others have said, don't use heat. You would not get it hot enough with a heat gun and a blow torch would be unsafe.
Just use penetrating fluid (that is not WD40, you need proper pen. fluid), then a good quality 9/16" AF socket and a long bar. If the bolt head has rounded you could get a 14 mm socket and hammer it on then use a long bar, but that could damage the socket (still, they are not expensive).

[mrducati]

Thanks for your response all of you. It is invaluable help for me to get this kind of advice! I have been using a ringspanner, and connected a larger ringspanner to it to get a bit more leverage. I have also sprayed them with WD-40 for a few days. I'll try and source 6-sided pipes and see if it helps. Seems mine are all 12 sided.

[Cooperman]

Thanks for your response all of you. It is invaluable help for me to get this kind of advice! I have been using a ringspanner, and connected a larger ringspanner to it to get a bit more leverage. I have also sprayed them with WD-40 for a few days. I'll try and source 6-sided pipes and see if it helps. Seems mine are all 12 sided.

And use a proper penetrating fluid first. A lot of people think WD40 is the right thing for this, but it's most definately not. You need 'Plus-Gas' penetrating fluid or its equivalent. 12-point socket should be OK if the fluid has worked its way in. A quality 1/2" square drive socket set is essential for working on a Mini.

[mrducati]

And use a proper penetrating fluid first. A lot of people think WD40 is the right thing for this, but it's most definately not. You need 'Plus-Gas' penetrating fluid or its equivalent. 12-point socket should be OK if the fluid has worked its way in. A quality 1/2" square drive socket set is essential for working on a Mini.

I have been using WD-40 for years, and not known it was the wrong tool! It often does not work, just like you said. I'll go and buy Plus-gas or similar, and see if it helps. This advice will help me in all my future work too!

[dklawson]

Are you splitting the caliper or removing the caliper from the car? Back in the day... we were always told to NEVER split a caliper. Today people seem to do it quite a lot.

Another possibility after you have applied the penetrating oil and allowed it time to work is to use an impact wrench instead of the paired ring spanners or a socket with breaker bar. The impact wrench will apply mechanical shock to the fasteners that should help break them loose.

[Yoda]

As a last resort, i use an air powered nut gun / impact driver with a six sided socket, but usually a 12" breaker bar will do it. Just remember you ought to replace the bolts with new ones when reassembling under these circumstances. And as Cooperman has said, WD40 is not really a penetrating fluid per se, but more a service aid. Plus gas all the way. Diesel works well too.

[mrducati]

Are you splitting the caliper or removing the caliper from the car? Back in the day... we were always told to NEVER split a caliper. Today people seem to do it quite a lot.

Another possibility after you have applied the penetrating oil and allowed it time to work is to use an impact wrench instead of the paired ring spanners or a socket with breaker bar. The impact wrench will apply mechanical shock to the fasteners that should help break them loose.

I am removing it from the car in order to change pistons and rubber seals. Hopefully the calipers itself is OK. Now proper penetrating oil is soaking, so hopefully the bolts will be out soon.
I don't have access to air tools unfortunately, but I have new faith they will come out now.

[dklawson]

An alternative to the air impact gun is an impact driver. They are well worth the money and small enough to fit most tool collections.

With an impact driver you use heavy duty sockets or bits on what looks like a steel screwdriver handle. You put the socket on the bolt, turn the handle the direction you want the bolt to go, then strike the end of the handle with a heavy hammer. The heavier the better. Cams inside the handle impart a very strong shock load and torque to the fastener and help brake it loose. Just don't hit your hand by mistake! The impact driver is a must have tool if doing heavy machine work and no air power is available.

The picture link below is for an impact driver.
http://www.toolnet.c...mages/47641.jpg

And the link below shows a person using an impact driver to remove brake parts from their car.
http://www.bombaydig..._driver_lg.jpeg

[mrducati]

It worked! It came loose! Thank you for all help guys!

An alternative to the air impact gun is an impact driver. .

It's on the shopping list!

[bmcecosse]

I suggest new bolts will be GOOD idea now - and a tiny smear of copper slip on the threads when you fit them - to the correct torque of course........