Hi Everyone,

About to put in new brake pads on the front discs and bleed the lines of my 78 xlh. I have never worked with brakes before (automotive or motorcycle) and was wondering if I should:

1. Empty the brake lines, change pads, fill and bleed lines?

2. Change pads, then deal with the fluid?

3. Deal with the fluid, then change pads?

Thanks everyone, after this step I will be riding my Ironhead again after a two month hiatus!

 

do not empty lines! remove the cover to the master cylinder,unbolt the caliper, push caliper in to compress piston (wrap master cylinder with rags to catch any fluid that may over flow)remove and replace shoes, re-mount caliper, slowly pump brakes up re-fill master cylinder if needed, if you want or need to change fluid after you are done just keep pouring new fluid in and bleed the brakes till it comes out clean, you dont want to drain the lines as sometimes it is a bear to get the air out!

 

Thanks Shep! I am about to go out in a few minutes to do this. The only thing I noticed different from your description and that in the FSM is they recommend to disconnect the brake line, take the piston out of the caliper and replace the seals. Not sure if this is do-able with the fluid still in place.

 

It is not necessary to replace the seals, unless the caliper is leaking.

The calipers will be filthy inside; i use spray can brake cleaner - on sale next week at Princess Auto $3.00 per can. I usually buy at least a few as it is very useful stuff.

After the brake cleaner rinse it all with brake fluid; but try to not get any on the pads.

If you do get some on the pads do not sweat it - just clean them well with your usual bike wash fluid and water rinse.

I set up a short step ladder beside the bike as a work table. I use a large C-clamp [with plastic protectors] to hold the caliper to it. I place a shallow bucket under to catch the filthy brake cleaner fluid. Wear rubber gloves.

In use that same C-clamp to press the piston into the bore before re-install; lid must be off master cyl, wrap in towel to catch overflow.

Use DOT 5 brake fluid; it will not harm any paint so spill all you want.

 

So I did not replace the brake pads. They look almost brand new (but 30 years old).

My reason for changing the pads was because I get a "CLICK!" sound when I touch the brake lever coming from the calipers. When I was inspecting the pads I noticed the calipers were not on very tight and had some play. I tightened the bolts the best I could, but it feels like they cannot get tighter, they still have play. The click upon braking is less pronounced but still there.

Other motivations for changing the pads were the fact that they squeal sometimes. Also, when it rains the front brakes are almost useless, only activating if I am pulling full force on the lever which will produce a tiny amount of braking. Again, that is only in the rain.

So all I did was tighten the caliper bolts. Also noticed the front brake light switch, which I replaced in November, is also no longer working. I'm sure more work needs to be done with the brakes but it will have to be another day. My ride was fun as hell though, it was only 3 miles but I had not been in the saddle for two months.

 

The clicky/clacky/rattle sound from the front brakes is common. To fix it you need to replace the bushings in the fork sliders. Can be left until it becomes really annoying.

I replaced mine a year, 15000 miles, ago and they just started it again.

The calipers are supposed to be loose like that. Part of the design. Do not overtighten the bolts - you risk stripping the nut-holes in the calipers. I put two drops of blue locktite on the bolt threads and tighten to just firm plus a little more - perhaps 10 to 15 ft lbs. Let the locktite do its work.

All disk brake systems are supposed to have the pads constantly in contact with the rotors. This has been referred to as "kissing the rotors". This mainly, among other things, keeps them warm and dry in the rain. What i do in the rain is keep the brakes lightly applied ahead of when i expect to need them.

Brake squeel can be simply dust. I had a problem with that a couple years ago when they were digging up our road. Aim the garden hose in there full blast, then avoid dusty roads. Are all the parts there including the thin "outer and inner plates"? These often get discarded. I am not certain what their purpose is but it may have to do with the squeeling.

 

Thanks for the tips Mick!

All of the plates were there and in-tact. Looks like I'm good to go, though I purchased a set of brake pads I don't need at the moment, I'm sure they will come in handy down the line.