Caliper freezing up

[XS1100 Newbie]

Ok you Gurus out there. I had an episode today that worried me. It is about 100 outside today, and i needed to make a 20 mile round trip run. The bike sat in the sun for about 4 hours before going home. Partway home my rear brake pedal got hard, and i felt the brake dragging. I knew what the problem was, but i don't know the reason. I wanted to ask if the XS bikes have a brake caliper problem in high heat? I realize that under real heavy breaking that may come into play, or just brake fade, but this i don't know. Reminds me of the old Dodge phenolic pistons siezing up. I will check it later when things cool down. Oh ya, i released the bleeder to help ease the brake, and the fluid was boiling hot, so i know i at least have to replace all the fluid.

[latexeses]

Original brake lines? Spooge hole plugged?

Two grown men couldn't push my bike if you touched either brake. Took 15 minutes for the preasure to bleed off. Found the problem when did a search here.
May be something else but that is my first thought.

[Crazcnuk]

This can happen if your reservoir is too full? When the fluid expands, in the heat, it has nowhere to go.

[CatatonicBug]

Sounds like a spooge hole problem. The XSive heat is probably just transferred from the brake disk to the pads, to the caliper, to the fluid. Lots of heat builds up FAST with the brakes when they drag.

Take the caliper AND the Master Cylinder apart (all the way) and clean them thoroughly. In the caliper, get under the seals, and in the grooves where the seals sit. In the MC, look for the spooge hole and try running a small wire through it. You'll see it come out the other side, into the cylinder bore. Try a bread twisty tie, with the paper removed. That way you can bend it just right to get into the hole.

[XS1100 Newbie]

Thanks for the info folks. I found the tech article on the spooge holes. The rear works just fine now, and it was pretty clean. The front however was really dirty. So much so that i would have thought it would have given me the problem. Got it all cleaned out, and they appear fine. I will test it tomorrow morning early so if i have to take it back apart, i will have time to ride later.

[Geezer]

Corrosion behind the the caliper seal will do the same thing. The only way to fix it is to take it apart, remove the seal and scrap out the crud. Also if you're lubing the slider with grease, it'll seize every time. The rubber parts will swell from the grease. Use a silicone based lube or I often use RCBS resizing lube both work well.

Geezer.

[XS1100 Newbie]

You were right Tony. I pulled the front master apart today because i just could not get any brake pedal (hand). That was probably to most disgusting looking master i have seen. I was all full of crap to the point that the piston would not return fully back. Cleaned it all up, inspected the bore, and put it back together. Done a world of good. Now i need to check the pads for wear on the front and rear. I'll still be coming to Detroit lake, even if i have to drive my pickup.

[redbone]

everyone's rite....take them [mc and cal] apart and start cleaning them and when you think they are clean....do it again.
craz is on to somethin also, the fluid will expand in the heat so take a little fluid out of mc when its really hot.
good luck

[Geezer]

I have a good but ugly master cylinder off my 79 standard you can have for postage if you need it. I was rebuilt a couple years ago and this year I put on a shiny new one from MikesXS.

If I can get the quad piston R1 calipers sorted out in time, I'll have those on my bike for the rally. It's almost a shame, I just rebuilt those last October and they only have a few hundred miles on them.

Geezer

You were right Tony. I pulled the front master apart today because i just could not get any brake pedal (hand). That was probably to most disgusting looking master i have seen. I was all full of crap to the point that the piston would not return fully back. Cleaned it all up, inspected the bore, and put it back together. Done a world of good. Now i need to check the pads for wear on the front and rear. I'll still be coming to Detroit lake, even if i have to drive my pickup.

[DGXSER]

One other option is air in the caliper. I had an XS750 years ago with a busted bleeder valve. I was much dumber and braver then and just rode it as is. After riding a short while the air in the brake expanded and slowly locked up the front brake. I'd slow for a light or stop sign and the bike would stop so fast I would almost high side it. Had to crank the RPM and dump the clutch to get it to go. I dropped that bike three times that way.

Much smarter now.

[XS1100 Newbie]

I have had no problems with my brakes since i dissmantled and cleaned both the front and rear master cylinders. Until today. It is a little over 90 degrees today, and i went for a short ride of about 5 miles. Didn't notice a problem until i shut it down, and went to push it into the garage. The rea was again partialy stuck. Seems that the intense heat is haveing something to do with it. The first time it was over 100 degrees, and now over 90 degrees. I checked the fluid level, and it doesn't look like i have too much fluid in the resevoir. Any ideas out there?

[fredintoon]

- - - Now i need to check the pads for wear on the front and rear. - - - -

Hi Newbie,
your signature line says you have a Midnight Special. One thing about any XS11 Special is that it has ATE pattern swivelling front calipers. If you are new to this caliper design you may not know this:-
The pads are SUPPOSED to be tapered. Don't toss them out and buy new ones like I did.

[CatatonicBug]

Ahh, but the LH ('81) only has tapered pads on the REAR! The fronts are flat and interchangable (left to right). The LG ('80) is as you describe though.

[XS1100 Newbie]

The pads are fine. I have not changed them, or removed them, so i know there is nothing there that would affect it. I just wonder if the rear brake pedal adjustment could be to tight, and what little expansion there is in high heat would cause the freeze up.

[fredintoon]

Ahh, but the LH ('81) only has tapered pads on the REAR! The fronts are flat and interchangable (left to right). The LG ('80) is as you describe though.

Hi 'Bug,
thing is, the only Special I have ever seen up close is my own XS11SG and the only other XS11 I could easily go look at is a '78 Standard so I did not know that about the LH.
Q1) HTF do they mount a swivelly caliper on the LH swingarm?
Q2) Does your LH have the axle on the front of the slider like other Specials and if so could I swap LH sliders onto my SG and thus get normal front calipers without increasing the front wheel trail?
Q3) Or did a dreaded PO swap in Standard fork legs on your bike?