Is brake fluid the nastyest stuff ever?

[Jethro]

I hate bleeding brakes.

I've installed new lines, overhauled my ft. calipers and master cyl. with new seals everywhere, and still my ft. calipers drag.

Any advice out there?

[focus frenzy]

disc brakes drag, that is the draw back to them, because of the hydraulic leverage advantage they can not retract as the lever travel would be excessive.
a somewhat light drag is normal, you might want to check and see if the master cylinder piston is fully retracting.
is the brakes binding up as you ride??

[ZacharyB]

My brakes drag a little too after sitting a long time. It's just how it is. The more annoying thing is how one of my discs is warped an eighth of a millimeter and makes an oscillating squeal during certain rpm/conditions

[Anonymous]

Hi Jethro. Used to live in Portsmouth about 40 years ago when my dad was stationed at Pease AFB. One of the few places I think I might move back to if I stop liking it here in Washington state.

Anyway, to your question. Though it may sound kind of radical, I took my disks off the bike and found a machine shop in town that did turning/grinding for car disks. He smoothed those suckers right up and in the process of course took off maybe 0.2 millimeter of metal. The replacement pads I had were too thick, and he was able to grind about 1/32" off each for me. I have almost no "contact" left at full piston throw; there is some but it is very even (i.e., no oscillating contact), it is tolerable for now, and I expect by mid-summer that everything will have smoothed up nicely.

Yeah, the residual contact bothers the perfectionist in me, but I know it will go away, and it is indicative of what I'd rather have -- brakes that work quickly when I need them, rather than hesitating because the pads need to travel a quarter inch before contacting the disk. Also, I theorize, the tight fit should keep rocks and all but the smallest debris from getting trapped between the pads and disk. This can't be a bad thing.

Anyway, it sounds like you've got a great setup with the new lines and all, so don't let a little flaw that is ultimately self-correcting detract from the satisfaction you should be feeling at your accomplishment. Enjoy!!

...Ross

[jhw84]

Dont know about the 1100's, but my bike has a floating caliper- meaning it isnt bolted securely to the forks, but rides back and forth on the bolts, using 1 piston to clamp the disc, much like a "C" clamp. If those bolts are not clean and lubed, it may cause excessive drag.

However, I agree with Ross... I would much rather have them dragging than have excessive lever travel. Going fast isnt fun unless you can stop fast.

[Jethro]

If those bolts are not clean and lubed, it may cause excessive drag.

Yeah, I spent a lot of time getting the bolts and the cavity perfectly clean and lubed it with the Suzuki specified synthetic lube. I even had those seals of and cleaned them up nice.

I guess I'll just ride a couple thousand miles and see how they progress. The drag isn't rediculas or anything, just annoying when you rebuild the entire front end and on little thing isn't perfect.

Regardless, brake fluid is about the nastyest thing I have ever had on my hands. I hate the stuff.

[DMPLATT]

Unfortunately as stated above, that's the nature of the beast. I just cleaned and lubed mine last night. I use white lithium grease as I was told by boat mechanics that it's the best to use around water.
If you look at the design, the pressure is on 1 side, there really can't be any clearance between the pads and the rotors. I'm thinking that would be bad. I'm sure when you put a few miles on it they will settle down.

[arveejay]

Re: Is brake fluid the nastyest stuff ever?

I hate bleeding brakes.

I've installed new lines, overhauled my ft. calipers and master cyl. with new seals everywhere, and still my ft. calipers drag.

Any advice out there?

Did you fully compress the brake cylinders back inside the housing before bleeding it? If air gets in there it tends to hang up at the top of the cavity. If you fully compress the cylinder and just let the fluid push out that last bubble it might get better. I use a c clamp. Just an idea.

[tfb]

The drag on the discs is worst with new pads; as things 'bed in' the drag will lessen.

My bike had a fair bit of brake drag when I got it. I found that one thing contributing to this, was the fact that the caliper brackets and their 'bolts' on which the whole caliper slides, were very worn. So much so that the brackets could not hold the calipers square in relation to the disc.

So I had the brackets (which are cast aluminium) rebushed at an engineering shop. The 'bolts' on which the calipers slide were unworn, so no work was needed there. Put it all together with a smear of grease (and a set of new rubber seals as the old ones had perished) to help things slide, and it's all been much better; not much drag at all.

Hope that helps.

Mike.

[sv650]

I even had those seals of and cleaned them up nice.

Did you clean out the groove that the seal sit in? The brake fluid precipitates as salts behind the ring, forcing it against the cylinder, preventing its' retraction.

Check http://oldmanhonda.com/MC/Rbrakes.html for more info.

SV

[argonsagas]

This won't directly answer your query, but I do recommend it.

When I first bought my 1100G, I did not know it's charging system had died, and, the same day I rode it home, I had it parked in a shopping mall lot.

Bike would not start, so I tried to push-start it. Problem was, I could barely move the thing, and, as soon as I stopped pushing, the bike stopped instantly.

A set of cables and a jump-start got it running, and got me home, where I put the bike on the centrestand and found out the brakes were so tight, I could only barely turn either wheel by hand, with the front decidely the worst.

A can of spray-on brake cleaner, applied VERY liberally, took off the gunk that had built up behind the pads, and everything immediately ran free.

[KEITH KRAUSE]

Jethro, there's a couple of very small holes at the bottom of the fluid reservoir. I think the return hole is the one closest to the bars? If this hole gets blocked at all, the piston in the master cylinder will return slowly or not completely after you release the lever. This will cause dragging. Most of the time though, you can see the lever returning slower than normal, but not necessarily.
If you bought some aftermarket pads, they are commonly not that precise/uniform in their thickness. You may have a set that's just a little thicker than the stock pads.
Since you serviced the caliper axle bolts, I would think it's one of the above things.
I assume the fork legs are parallel? Did you loosen up the fender/fork brace and axle clamps, and pump the forks several times to align the forks?

[Jethro]

Thanks for all the responses here guys!

If this hole gets blocked at all, the piston in the master cylinder will return slowly or not completely after you release the lever.

I made sure this was clear. Hap had already warned me of that, so while I had the master cyl. piston out I ran some very thin gauge wire through it to make sure it was clear.

If you bought some aftermarket pads,

Actually, the pads that were in there only had about 1000 miles on them, so I deglazed them and put them back in. They looked fine.

I also made sure the fork legs were good, but I didn't align them exactly like you suggested, so I'm gonna do that again tonight.

A can of spray-on brake cleaner, applied VERY liberally, took off the gunk that had built up behind the pads, and everything immediately ran free.

I had the entire brake system (master cyl, brake lines and calipers) off while I was waiting for my new lines to come in. They were so clean internally and externally, it was rediculas. I went through about 6 yards of cloth rags, a box of pipe cleaners and about 45 Q-tips. Those puppies had no gunk.

I'm thinking I just need to ride em a little more. If I spin the front wheel by hand, it will go an entire revolution before stopping. Maybe I'm just being way too critical.