can brake lines cause pad glazing

[sherman204]

I have a 79 f. It seems that the front brakes won't completely release and there for they glaze over and squeak. I have rebuilt with kits every thing but the brake lines. The lever is hard to pull. If brake lines are needed how do I go about deciding what size and where to get them after market. I need to shorten the upper line because I installed some short club man type bars. I could use some sound advice here.. This has been going on for some time. I take the pads out rough them up then wait for the squeak to return usually with in 200 miles.
Bob

[Larrym]

Release me... and let me Brake again.

If the front brakes are not releasing then you can tell by trying to turn the front wheel by hand. (The rotors will also get hot during normal driving.) If you have rebuilt everything then I presume that you also rebuilt the front master cylinder and cleaned out the spooge hole. If you haven't cleaned out the spooge hole then see this tech tip:

http://www.xs11.com/xs11-info/tech-t...oge-holes.html

I (embarassingly enough...) still have the original brake lines installed on my 30 year old bike. I did R&R the entire front system (calipers, pistons, seals, pads, master cylinder) and cleaned everything out. Then I completely flushed the system with new brake fluid. My brakes do not drag so I'm going with a "No. Old brake lines will not cause the brakes to drag."

One thing I did during reassembly is to use a product called "Disc Brake Quiet" on the metal to metal parts of the pads and pistons. (Available at the auto parts store in various sizes and colors...) From my experience just about all disc brakes will tend to "squeal" or make noise when the right pressure and vibration is present. So I used the "Quiet" goo on all the right places in the assembly. No noises whatsoever. My pads are "smoothed" by the actions of the rotor now and that is a normal outcome of the brake pads "breaking in" properly. Glazing occurs when the heat/friction goes way beyond what the pads were designed for and if that's what's happening then your front pads will have a real "burning" smell after a ride.

I also used a high temperature "anti-seize" on all the metal slides/bolts/friction surfaces. (Silver stuff made just for this application...)

Getting the SS brake lines for my bike is on the list for next year so I'll be watching for any one to dangle the right parts/supplier in this thread.

[CatatonicBug]

If the brakes won't retract, it's because the spooge hole in the Master Cylinder is clogged. Clean it, along with the groove UNDER the seal in the caliper, and you'll be good as new.

[bikerphil]

I've heard of old brake lines deteriorating on the inside and causing binding problems. The rubber bits detach and plug things up. When you rebuilt the calipers, did you thoroughly clean the caliper seal groove? Also check the spooge hole as mentioned. To measure for new SS lines, you can take a long piece of thin hose and route it next to the existing line and measure for the desired length.

[Geezer]

Sometimes the brakes won't retract because the sliders were lubed with petroleum based grease. The rubber in the slider negatively reacts with this type of grease and will seize.

Take them apart and wash the rubber bushings with soap and water and degrease the aluminum bushing with acetone. You are supposed to use silicone grease but I often use RCBS cartridge case resizing lube and I find it works even better...

Geezer

[sherman204]

My master cylinder could be the villan

I have long felt that the master cylinder could be a problem the res. is checked but no leakage. Could I have a problem with the top brake line being too long and in a position to cause binding? I will take the time to remove the brake grease I used to coat all parts and switch to silicone. I understand about the spooge or what ever it is called being part of the master cylinder and have clean it. Have any of you guys had a problem with that block where the single brake line splits in two being clogged? My brake lined show checking on the outer covering does that raise any flags? With all that said lets help me find new brake lines, no I do not want S.S. And does any one have any good supplier for a after market master cylinder? Bob

[CatatonicBug]

Brake grease? The ONLY thing that should touch the internal brake components is clean brake fluid. There are a couple of small points that get greased on the caliper, but that shouldn't be a problem.

Why wouldn't you want SS lines?? That's the ONLY way to go when replacing brake lines. There is no reason to use old technology when something so much better is available. I believe Mikesxs.com sells a front MC that will replace yours. Not sure which one is the right one though.

[trbig]

A lot of times, moisture gets in behind the O-ring in your caliper and eventually causes some corrosion. This corrosion builds up over time and causes the O-ring to push against the piston harder than it was designed to, and keeps it from retracting. If you simply pulled the old O-ring out and put the new one in without using a dental pick or such to clean and scrape behind it, this could be your problem.

BUT.. before doing all of that, I would try to clean the spooge hole first since it doesn't require any disassembly and re-bleeding of the system. I found a very fine sewing needle that does the job well. I bent it in the middle to reach the angle it needs.

Also.. if there is a bubble trapped somewhere in the line, as you ride and apply pressure, the brake fluid warms up a bit. A bubble will expand and keep the caliper from retracting.


Just some thoughts and suggestions.


Tod