Front Disc issues

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Front Disc issues

Postby Blurredman » Thu Jun 29, 2017 3:40 am

Hi guys,


Just throwing out what i'm experiencing at the minute. I'm aware of the things I am going to do but just wondering what you guys thought.


2 months ago I went offroading on my 251, and after coming back found my front brake seizing on. I took the caliper apart, thoroughtly cleaned it and the pistons, pushed back the pistons and made sure they operated properly.

It worked for a little while until It developed a loud and obnoxious squeak when applying the brakes, I took it all apart again, only to find that this time it gave the same squeak only when I didn't brake! - So all the time..
The brake was free, but I would notice the sound disapear when leaning right, and become more apparent when leaning left.

I then decided to swap brake pads with a new set I bought for future use. The old pads were still in pretty good condition.

I did breifly wonder whether the reservoir is completely full, as obviously the new pads are a lot thicker, however I didn't get too much resistence compressing the pistons..

Now, my next option is to re-test the application of the pistons, but in my opinion I might just swap with another caliper I have spare (the one that actually belongs on the bike) and get this sorted because this is an every day bike and the disc is getting extremely hot.
1972 MZ ES250/2 - 16,000 miles - The project! :)
1979 Suzuki TS185ER - 9,000 miles - Mud :)
1981 Honda CX500B - 91,000 miles - Long Distance :)
1987 MZ ETZ300 - 38,000 miles - Sun :)
1990 MZ ETZ251 - 49,000 miles - Commute :)

ftp://blurredmanswebsite.ddns.net/Vehicle_Documents/MZ_Documents/
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Re: Front Disc issues

Postby DAVID THOMPSON » Thu Jun 29, 2017 7:59 am

did you check the bearings is the wheel running true

the bearings in the wheels on my 2002 rt125 were shot and had high noise at 12,000 miles
my old bmw wheels seem to have bearings that last forever if you keep them greased

is the handle bar lever adjusted proper it must come to rest at a point where the fluid can pass in and out of the tank on the lever
or on a hot day the brake will come on by them selves as the fluid expands also hot pads can make fluid expand and put the brake on causing more heat
Dave 2002 MZ RT125+1995 Saxon Tour(500cc)
1997 MZ 660 Traveller+6/13/09 WV USA
"IN the end times the IDIOTS will be in charge
of everything"
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wd8cyv at yahoo dot com
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Re: Front Disc issues

Postby Blurredman » Mon Jul 03, 2017 3:28 am

So the result is so so:

I checked the bearings and they were fine.
First I changed pads, then found that the brakes were seizing on and after two days of use I just had to do something abuot it.

So I changed the caliper with a spare. I used my old pads again, and other than the occasional squeek every now and again it seems fine, though I will have to try and bleed the brakes again as it feels quite spongey and the lever has a lot of travel. It's safe and usable, and actually had a benefitial side effect that I found it very difficult to lock the front brake with it this way.


The replacement caliper is the one that was originally on the bike, which is a later type. The position of the bleed nipple and line make it really awkward to tighten and loosen the nipple. :x



Other than that i've been working on getting my Suzuki TS185 on the road again.. Seized drum brakes (rust in the drums) and a replacement carburettor sorted that.
1972 MZ ES250/2 - 16,000 miles - The project! :)
1979 Suzuki TS185ER - 9,000 miles - Mud :)
1981 Honda CX500B - 91,000 miles - Long Distance :)
1987 MZ ETZ300 - 38,000 miles - Sun :)
1990 MZ ETZ251 - 49,000 miles - Commute :)

ftp://blurredmanswebsite.ddns.net/Vehicle_Documents/MZ_Documents/
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Location: South Wales

Re: Front Disc issues

Postby AlanJ » Fri Jul 21, 2017 3:02 pm

HI Blurredman,
Sorry I am late in posting this but one of the problems with a squeak on a cars brakes can often be sorted with a light smear of copperslip on the rear of the pads, obviously not too much or it will get round the wrong side, It might be worth a shot though. I must say the post about expanding hot fluid is a good one, not come across that one before,
Wish you well Alan.
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