The New And Improved Unofficial R65 Forum V2

Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: k_enn on July 02, 2012, 09:29:17 AM

Title: A dumb Question on Brakes
Post by: k_enn on July 02, 2012, 09:29:17 AM
Over the weekend I was changing the brake fluid on the front brake, and bleeding the line.  That part of the job went well, and the brake lever now feels nice and firm again.  

On the test ride after the fluid change, I noticed that although the brake lever was firm and feeling fine, the front brakes were really lacking in stopping power, and now there is a squeal (which there never had been).  I believe that I may have gotten some brake fluid on the pads or rotor during the fluid change.  I used some spray brake cleaner on the rotor, and sprayed the pad area as well.  The rotor seems fine now, and that improved the stopping action some.  But the brakes are is still weak and with a squeal.  I am fairly certain that although the pads are making contact with the rotor with plenty of pressure, they are just not grabbing the rotor.  I am assuming that there may still be some fluid residue on the pads.

So, the question is -- assuming that I did indeed get brake fluid on the rotor and pads, is that something that will wear off with usage?  Or am I better off taking out the pads and cleaning/sanding the pad surface?

BTW it is a 1982 with the ATE brakes.

k_enn
Title: Re: A dumb Question on Brakes
Post by: Bob_Roller on July 02, 2012, 09:53:59 AM
You can remove the pads clean, then sand them down a bit .

The squeal you hear, are the brake pads vibrating, a quick fix for this, is applying something like Permatex Disc Brake Quiet (if you can find it) to the back of the pads, where they contact the caliper piston, it's an aerosol product comes out a light blue color and when cured, adheres the pad to the caliper piston to prevent the vibration from happening .

A few members here have used plain old 'rattle can', autmotive spray paint on the back of the pads and had good results .
Title: Re: A dumb Question on Brakes
Post by: tvrla on July 02, 2012, 10:05:17 AM
Also clean out the holes in the disc. Crud builds up in them and is re-introduced to the disc surface when heated, contaminating the pads.
Title: Re: A dumb Question on Brakes
Post by: k_enn on July 02, 2012, 11:00:45 AM
One more quick question - when removing the old pads for cleaning, should I take the caliper off of the fork so that the rotor is not in between the pads and I have more space at the pads, or can I just slide the pads in and out without doing that?  My gut reaction is to remove the caliper, but the owners manual shows the replacement of brake pads being done with the caliper in place.  

k_enn
Title: Re: A dumb Question on Brakes
Post by: EGRG on July 02, 2012, 11:37:23 AM
Agree with Bob_Roller: I once was waaay to liberal with some WD40 cleaning the front end and lo a behold I completely lost bakes on the front. Had to remove brake pads, clean, sand and compressed air did the trick. Even after cleaning the it took some miles before really good braking results returned to the system. Scary for a little while before I cleaned the pads.
Title: Re: A dumb Question on Brakes
Post by: Barry on July 02, 2012, 11:41:39 AM
Quote
when removing the old pads for cleaning, should I take the caliper off of the fork so that the rotor is not in between the pads and I have more space at the pads, or can I just slide the pads in and out without doing that?

You don't need to unbolt the caliper. Just remove the plastic cover and tap out the pad retaining pins from the wheel side of the caliper.


Whenever I clean the disc with brake cleaner the brakes are relatively ineffective for a few miles until the disc accumulates a a layer of brake dust.
Title: Re: A dumb Question on Brakes
Post by: Ron_S. on July 02, 2012, 11:44:00 AM
Quote
I once was waaay to liberal with some WD40 cleaning the front end  

What were you cleaning with the WD40?  
Title: Re: A dumb Question on Brakes
Post by: EGRG on July 02, 2012, 12:40:47 PM
Quote
What were you cleaning with the WD40?

I was cleaning the lower front forks and the outside of the calipers. Also used some to degrease the hub assembly between the disks. I thought I caught it all with the rag but all in all a foolish venture. I would brake in march and stop in april, but that Brembo logo sure looked shiny.  The good thing was that on disassembly I found out that I was missing a caliper bolt on one side!!  
Title: Re: A dumb Question on Brakes
Post by: Ron_S. on July 02, 2012, 12:54:40 PM
Never thought of using that as a cleaning agent, but it makes sense.  And I'm a newby and I've been wondering what to use, since most engine cleaners say they can't be used on motorcycles (aluminum).  
Title: Re: A dumb Question on Brakes
Post by: raymr on July 02, 2012, 01:36:59 PM
I have also used WD40 for 'cleaning' purposes but I'd be afraid of it slowly eating up the paint finish over time. Maybe it's an unreasonable fear, however it is a solvent.
Title: Re: A dumb Question on Brakes
Post by: Ron_S. on July 02, 2012, 01:42:01 PM
I only want something to get oil and stuff off the lower part of the engine/tranny,  thanks for the warning.  I was surprised when I could find no engine cleaner for aluminum.  And there are some really hard to reach places, so just a scrum with hot soapy water isn't going to do it, even with the tiny brushes I could find.  I can get to most of the frame/painted parts, though.  
Title: Re: A dumb Question on Brakes
Post by: EGRG on July 02, 2012, 01:54:27 PM
Ron: Try some Throttle body cleaner on the tough to get to places. Dries off very fast. I like the wd40 better though.
Title: Re: A dumb Question on Brakes
Post by: Ron_S. on July 02, 2012, 03:31:58 PM
Thanks.  Is that the same thing a carb. cleaner?  
Title: Re: A dumb Question on Brakes
Post by: EGRG on July 02, 2012, 04:26:19 PM
Yes.  The larger can has more pressure for hard to get places.
But dries quickly with a whitish hue.
Keep some handy for when you have to clean your carb jets, floats and bowls.  Work's very well.
Title: Re: A dumb Question on Brakes
Post by: montmil on July 02, 2012, 08:03:33 PM
WD-40 is much like kerosene. It has its uses on bikes but avoid using it in and on handlebar switch assemblies as the spray does not totally evaporate and what remains becomes a dust and dirt magnet.

WalMart sells their 'house brand' of carb cleaner at approx one-third of the "name" spray cleaners. Does a fine job de-gunking crankcase bottoms, greasy nasties and such. Depending on the paint, the carb spray can also be an effective paint destroyer. Kinda like his distant cousin, brake fluid.
Title: Re: A dumb Question on Brakes
Post by: k_enn on July 04, 2012, 11:21:53 AM
Thanks everyone for you input.  Pulled the pads, and cleaned everything up real good.  What an improvement.

Also, found a good way to clean the holes in the rotor.   I used a .38 caliber brush for cleaning an handgun bore, and ran it through the holes.  That got a lot of crud out.

k_enn
Title: Re: A dumb Question on Brakes
Post by: montmil on July 04, 2012, 12:11:40 PM
I'm a 9mm guy myownself. :D
Title: Re: A dumb Question on Brakes
Post by: EGRG on July 04, 2012, 12:34:53 PM
Invariably guns and beer have a way of participating in the repair of almost anything on the R65.  :)
Title: Re: A dumb Question on Brakes
Post by: montmil on July 04, 2012, 01:13:53 PM
Quote
Invariably guns and beer have a way of participating in the repair of almost anything on the R65.  :)

I like that, Victor. [smiley=thumbup.gif]

There have been times I've celebrated a successful repair with a frosty bottle. Other times, I'm ready to shoot the farkin' bastid [smiley=rifle.gif]
Title: Re: A dumb Question on Brakes
Post by: k_enn on July 05, 2012, 12:05:15 PM
Quote
I'm a 9mm guy myownself. :D


Personally, I prefer .45 ACP.  But that brush was too big for the disc holes.     [smiley=laugh.gif]
Title: Re: A dumb Question on Brakes
Post by: k_enn on July 14, 2012, 03:29:51 PM
Update:  The cleaning and bleeding made it much better, but it still was not as good as it used to be.  So I replaced the pads, and now it really grabs well.