Topic

I need to replace the front brake disc,while I`m working on the off side of the car I`ve removed the two screws ,but its solid and I cannot shift it .Ive soaked it in penetrating oil and clouted it with a hammer,but its stuck firm Any ideas Len

Sorry I forgot to add ,on U TUBE someone suggested to put a bolt through one of the holes that is used to fix the caliper on with a nut on the other side and screw the bot in against the disc Im wondering if it may put too much pressure on the casting Im willing to supply signed copies of my drawing,for a small fee !!!!! Len

I've used the bolt trick multiple times with great success, always works to remove an otherwise stuck disc.

I used a puller as shown in the picture below. The red spots are the two areas where I played the heat from two blowlamps, which certainly helped. I have subsequently realised that I SHOULD have put something like a large socket over the hub, so that the load would be taken by the hub directly, rather than via the wheel bearing.

DO NOT use a hammer on the back of the disc! That WILL overload the wheel bearing(s) and probably cause Brinelling of rollers into races.

A single word can convey a tremendous amount about a person; Brinelling is that word in your post.
M

+1 on the bolt through method.

I’ve never had a problem with disc removal, partly because whenever I acquire a vehicle the brakes are the first enemy to be tackled. If the car hasn’t had time to accrue any rust, IE new; it’s a problem for the garage.
A good squeg of Plusgas the day before the operation, bit of bias from a puller & with a sharp tap from two diametrically opposed rubber hammers & I have it in my lap.
A good wire brush & a smear of copper slip, a thread tap run down the securing screw holes, a nudge around the disc to ensure it’s seated, new screws & all done.
Then it’s a matter of spinning it up to ensure it runs true.
M

Airportable wrote:

A single word can convey a tremendous amount about a person; Brinelling is that word in your post.
M

Brinelling was a word I first came across during training at Rolls Royce. Apparently, some jet engines failed dramatically as a result of bearing failure, very early in their operating life: The subsequent inspection of failed engines revealed Brinelling, where races were indented by the ball bearings. Subsequently the transportation frames for jet engines had their own suspension systems, to prevent shock loads from an under-loaded, harsh suspension on transport lorries.

Later in my life, I sold Hardness Testers, including Brinell Hardness testers. Ideal for testing cast materials, where micro porosity makes Vickers or Rockwell tests less reliable or potentially misleading. That gave me the clues to understand where the expression "Brinelling" came from.

Probably no-one particularly interested, but perhaps Airportable now knows why I used the word!

From the use of that word in that context told me that you were knowledgeable in bearings & failures of such. To have that information implies that you must have worked at a high level in engineering & probably aerospace.

Airportable wrote:

From the use of that word in that context told me that you were knowledgeable in bearings & failures of such. To have that information implies that you must have worked at a high level in engineering & probably aerospace.

Well never " at a high level", but my apprenticeship was at Rolls Royce Bristol Engine Division, back in the good old days where governments had the sense to have a scheme called the Engineering Industry Training Board: EITB. That took a levy from all Engineering Companies over a certain size, then paid that money out to companies (like RR) who ran "approved" Apprenticeship courses. As a result, when RR went bust on February 4th 1971, no apprentices were made redundant.

My career strayed from "engineering & probably aerospace", though I sold lots of kit to BA Systems, Rolls Royce Aero Engines.

These days those who purportedly work at “a high level” wouldn’t know which end of a gas turbine engine sucked, which end blows & wouldn’t have a clue as to what went on in between.
I my opinion a Rolls / Bristol apprenticeship is as close to being gold plated as you could get.
M

Ihavent had time to try to remove the disc yet .Ive been spraying with penetrating oil .I have a worry that the casting may crack usingthe bolt metod ,but there doesn`t seem to be an alternative .I`ve bought a new disc so be nice to get this job finished Len