Does this sound like the spooge hole?

[Danny Crawdad]

I have never been happier with the title to a post.

I have a 1981 XS11 Special that runs great most of the time, and right now it's not. About a week ago I was on the way home, and started noticing that it was more difficult to take off from a stop. I was a few miles away from home, so I parked it, and as soon as I stopped moving, the rear brake seized up tight.

I loosened the bleeder, which released the caliper, and decided to give it another ride today. Same thing, slowly throughout the ride the rear brake began to hold more and more pressure, until I was stopped at a red (and then subsequently green) light with the rear brake locked up. I had a wrench with me this time in anticipation, cracked the rear bleeder, and was immediately back in business, except now I don't have any rear brake pedal pressure at all. I'm guessing I probably drained the master cylinder or close to it, or something. Whatever, it's parked.

I'm all hot and sweaty from the ride so I haven't looked into it yet, but before I start tearing down things, does this sound like the spooge hole on the rear master cylinder?

The brake lines are new, pads are new, master cyls were cleaned well when I bought it but I was warned that I might have to clean the release hole again.

Other than that, the bike brakes great! If I can get this resolved, I can start looking into things like "the mystery of the electrical short", and its exciting sequel, "why is my gas tank leaking".

[Incubus]

Yeah, it does. Did you rebuild the caliper? It also could be dirty, making it difficult for the piston to retract right.

Patrick

[Shacknasty]

Don't wait around on that leaky gas tank...

[natemoen]

Sounds exactly like the spooge hole. It is there to allow for the release of pressure.

[cywelchjr]

The spooge hole or the free play adjustment on the rear brake lever which can cause the exact same symptom. Make sure that you have a slight amount of free play in the master cylinder piston before it starts to try and cause braking, if it's too tight, it can hold the piston past the spooge hole which makes it act just like the spooge hole is clogged.

This is not from personal experience, but from another member who ran into this issue and fought with it, and found that they had the rear brake lever adjustment too tight causing the problem.

[Danny Crawdad]

Don't wait around on that leaky gas tank...

Wow, no kidding. It's just damp around the left petcock right now, I have a POR-15 HD Tank re-sealing kit coming, and already have the petcock rebuild kits, so that should be done soon. Waiting on POR-15 to get it to me.

I did forget to mention that the calipers were pulled apart and cleaned well.

I did adjust the rear brake lever several weeks ago -- I pulled the lever off of the spindle and rotated it down towards the ground a notch. I don't think that would affect the free play or brake engagement, but I may not know what the heck I'm talking about.

Having read the rear-spooge-hole-cleansing () howto, I know it can be done relatively easily, but the article mentions pulling the whole master cylinder if you want to give it a really good cleaning. I've read the manual and it looks simple enough, but the article sort of alludes that it will be a pain in the ass. Do you think it's worth it to just clean the hole first, or should I pull the whole MC since I'll be partially disassembling it anyway?

[Danny Crawdad]

Nevermind, I just pulled it in the dark in about 5 minutes. Now I get to clean it in the luxury of my kitchen. Let's see how the wife likes it.

[cywelchjr]

If you rotated the pedal down 1 spline that wouldn't have moved the adjustment, but it's an adjustment that's easy to get wrong when putting things back together after rebuilding the master cylinder, so you need to check it and make sure it returns all the way to at rest when the pedal is released. So I would suggest that you check that first, as IHMO that is the most likely cause of the problem. However, if you find that it is returning to the fully at rest position, they check the spooge hole, but all the cleaning of the spooge hole in the world won't do any good if the pedal is holding the master cylinder partially engaged.

[Danny Crawdad]

I am relatively confident that the play was set correctly when it was rebuilt, and it worked fine for nearly 6 months, this is a more recent problem. It does sound like I need to make sure I get it correct when I reinstall the master cylinder, though.

If I'm missing or presuming something, please don't hesitate to tell me :P

Edit: There is an amount of sediment draining out of this master cylinder when I removed the drain plug, I bet it's good and clogged. Good chance to clean it well, put it back on and adjust it as it should be, and fill it with good fluid.

[cywelchjr]

If you made ANY adjustment to the position of the brake pedal, it's possible for that to affect that adjustment, it doesn't take long to check it, and if you make said adjustment around the same time the problem started that would REALLY make me suspicious. All the lever adjustments interrelate, so what I'm saying is take the 15 minutes to double check all those adjustments, it will save you a LOT of time if that's the problem, if not, you've verified where things are before taking it apart, which is always a good idea.

[Danny Crawdad]

I probably screwed the pooch on that because I already pulled the master cylinder off, but I'm glad I did. The hole was very clogged, and I pulled a lot of sediment through it. I'm running clean brake fluid through it now to flush.

[cywelchjr]

If it's that dirty you should probably make sure the whole system is clean. That sounds like the PO (I understand you to say that's who cleaned it before?) didn't do a good job. I do a full brake bleed at the end of each summer, and never have any trouble with mine, speaking of which, mine are just about due. Next year I plan on installing braided SS lines at the same time and such, but not this year, I'm sticking to a serious budget.

[Danny Crawdad]

If it's that dirty you should probably make sure the whole system is clean. That sounds like the PO (I understand you to say that's who cleaned it before?) didn't do a good job. I do a full brake bleed at the end of each summer, and never have any trouble with mine, speaking of which, mine are just about due. Next year I plan on installing braided SS lines at the same time and such, but not this year, I'm sticking to a serious budget.

Yep, as soon as I drained the fluid out of the master cyl I knew I was in for a flush, it came out relatively clean, but with sediment at the bottom. Spooge hole was completely blocked, had to work to get a mandolin string through. It's good and clean now, though. If I had a new container of brake fluid, I'd put it back on the bike. Front is behaving well, but as soon as I'm confident with the rears I am going to pull them apart too.

SS lines are on my list also -- they have made a real difference on the other vehicles I've put them on. These lines are new (I'll give the PO credit for that), so I am probably going to wait until next season to do that also. Going to paint the calipers at the same time, I think.

[Shacknasty]

Gas leaks should really not be fixed with tank liner, yer just putting off the problem that way. Welding or brazing or even silver soldering would be the preferred method of fix. We take plenty of chances when we ride a properly functioning machine, why stack the deck against yourself?

[Danny Crawdad]

The tank sealant kit is for rust and is a fuel sealant, the slight gas leak is from the petcocks. I have a rebuild kit for them, but I'm waiting on the tank kit to come in so I can tear it down one time and do it right. The fuel tank is sound and doesn't require any metalwork.