Brake TroubleShooting/My new bike

Hey guys!

I picked up a practically mint condition (for a 25 year old bike) Honda MB5 last night.

Everything works great and I am having a blast learning techniques...

Today for the first time I took it into 5th gear and also the first time I attempted (successfuly) to blip/add some throttle mid downshift to make it smoother... I also got a few waves from fellow bikers as I passed by (mostly sports bikes) which felt great considering the tiny ride I was on

Anyways, most everything works great, just one issue... The front hydralic disk brake.

It feels weak to me, I know this is a 200 pound bike and all I have to compare it to is a bicycle but my bicycle brakes feel stronger... When going down my steep hill today at 15mph I was able to basically give it as much pull as I could but it was not a significant braking effect.

Rear drum brake works great though so I have been alright cruising around, and the front does help but I would have thought the feel would be more significant.

Previous owner said he had just replaced the brake fluid, however the master cylinder is a bit low.

I plan to fill it but I cant imagine this makes a huge difference.

Stock pads are in place (25 years old) but the bike has under 3,900 miles on it and from a visual inspection (havent taken them off the bike, if I do what should I look for?) they appear to have barely anything worn off of them...

I do have a set of replacement pads, should I try them out?

Its a relativly small brake pad but like I said, I have ridden bikes with MUCH smaller disk and even standard brakes that get upset if you "slam" the brakes, however this one feels so weak that it deals with the slam just fine...

Advice?

[cecilbdml]

It's the nature of the beast with smaller discs. There isn't as much leverage the pads can use as far as slowing the bike. And most folks don't re-adjust the drum much; they just replace the shoes when they start squeaking or grinding.

DO NOT use kevlar pads on the front. They live longer by not resisting as much, but they give you a weaker feel when you use them. Sintered are far better. Make sure the rear drum is adjusted every now and again (get a service manual before trying).

What sort of adjustment to the rear are you refering to?

As far as I understand from my service manual you just replace the shoe in back when the indicator arrows on the outside show that the pad is out (mine show that I have plenty left), but like I said my back brakes feel great...

Its the disc brake up front that worries me...

So you think its just the nature of the smaller disc?

I mean it just feels really weak...

And right now I have a set of Honda Genuine Brake pads, there are some higher performance ones available but Ill keep in mind... sintered only, no kevlar.

[clockdaddy]

Since there are only 2 bolts holding on the caliper, I'd pull it off and check the old pads. It sounds to me as though they may have crystalized. Frankly, it isn't that hard to crystalize brakes especially if the rider was not experienced.
I replaced the pads on my 83 Nighthawk with ceramic pads. Ceramic doesn't give that black dust we so often see on bikes and cars.
Check the rotor to see if it looks burnt! A bluish, black surface color indicates that they have been heated up tremendously. If the rotor is discolored and glazed, have it turned.

CD

[JimmyAcorn]

Originally Posted by jraice

Hey guys!

I picked up a practically mint condition (for a 25 year old bike) Honda MB5 last night.

Everything works great and I am having a blast learning techniques...

Today for the first time I took it into 5th gear and also the first time I attempted (successfuly) to blip/add some throttle mid downshift to make it smoother... I also got a few waves from fellow bikers as I passed by (mostly sports bikes) which felt great considering the tiny ride I was on

Anyways, most everything works great, just one issue... The front hydralic disk brake.

It feels weak to me, I know this is a 200 pound bike and all I have to compare it to is a bicycle but my bicycle brakes feel stronger... When going down my steep hill today at 15mph I was able to basically give it as much pull as I could but it was not a significant braking effect.

Rear drum brake works great though so I have been alright cruising around, and the front does help but I would have thought the feel would be more significant.

Previous owner said he had just replaced the brake fluid, however the master cylinder is a bit low.

I plan to fill it but I cant imagine this makes a huge difference.

Stock pads are in place (25 years old) but the bike has under 3,900 miles on it and from a visual inspection (havent taken them off the bike, if I do what should I look for?) they appear to have barely anything worn off of them...

I do have a set of replacement pads, should I try them out?

Its a relativly small brake pad but like I said, I have ridden bikes with MUCH smaller disk and even standard brakes that get upset if you "slam" the brakes, however this one feels so weak that it deals with the slam just fine...

Advice?

Advice? Yes. Don't compare todays technology with that of 25 years ago. AND, change the pads.

Peace

[iamgumby]

25 years and 4k miles? The brakes are prolly in shock that they are being asked to move. Start with maintaining low speeds and just use the brakes. So long as they are not leaking fluid from the caliper or any of the connections and the hoses are in good shape, the fluid is clean and you have a hard lever you should be OK for a while.

There is no correlation between "used little" and "well maintained". Hydraulic systems on motorcycles require periodic maintenance. Maybe your seller did this? I dunno. That fluid should be flushed and changed every year or two. The lines should be changed on a schedule, too.

If light usage doesn't improve that front brake pretty quick you might have a maintenance job ahead. When a bike is left to sit - and fluid just sits - it breaks down - you might be able to see a black residue on the bottom of the master cylinder. (rubber seals and hose innards)

If there is - that's a clue. Use a syringe (turkey bulb thing, ya know?) and carefully draw out that old fluid. Use a clean paper towel with some new clean brake fluid on it and wipe that crap out of there. Don't fiddle with the lever while the resivoir is low or you put air in your system. Put NOTHING in that resevoir other than new clean brake fluid (no simple green, windex, carb cleaner or anything else). Fill your master cylinder back up. Then bleed the brakes out (just like a car) until you have clear running fluid. That should wash any deterioration and residues out of any check balls and passages.

If you're going to keep this bike for any amount of time - better get a manual - Clymer or Haynes - both good and about $30.00. Shoot, your library might even have one!

I have a haynes manual...

Thanks for the tip on sucking up the master cylinder before refilling and bleeding...

The previous owner SAID he had changed the fluid but who knows... better safe then sorry...

Brake feels solid which makes me think it could just be glazed brake pads but I thought I'd see what you guys thought.

I think to start Ill change the pads after an inspection of the current ones, and top off the fluid, maybe bleed it a bit and see what color the current stuff appears to be...

I am guessing the rubber liners are the original, would you guys definetly advice replacement? They look to be in very good condition with no signs of damage/splitting/etc...

Ill likely go with steel braided lines for a bit more power...

[JimmyAcorn]

[SIZE="4"]

I have a haynes manual...

[/SIZE]

I thought that read "heinous" manual.

Peace

[gimig]

Hey jraice,
How about posting a pic of the new ride....

Ill see if I can get a few pics...

Bike is in the garage and its pouring rain so I cant take it out but I should be able to get a few okay pictures...

I have some decals, a new seat cover, lowered handlebar and an "engine spoiler" coming soon, Ill post more pictures after those arrive...

And as I continue to add some parts Ill keep the pictures coming...

It really is a nice looking bike for an 82', I even had a guy ask how many CC's it was and I also mentioned it was a 1982... He was shocked, thought it was brand new!

Here you go guys...

[iamgumby]

25 years old?!?!?! You kidding me?!?!?! That thing looks showroom clean! Great acquisition, man!

Yeah it is great looking for its age, the tank is flawless... The plastics have a couple VERY light scratchs, and there is a 1" crack in the plastic but its completly hidden and easily repairable whenever I get to it...

I am going to go out and change the pads now and then Ill be coming back in to see what respones I get to this...

I could not get DOT 3 fluid but picked up some Bel Ray Super DOT 4 that SAYS its compatible with DOT 3-4....

Safe to use?

Thanks

[iamgumby]

From your reading of the container I would concur it's OK; especially if you're going to be flusing most of the old out anyway. Be sure to protect your surfaces - brake fluid will eat the crap out of paint without mercy! Works the same as a paint stripper.

Ya also the back of the container has a euro and a US spec...

For US it says better then DOT 4 (but compatible with DOT 3) and the Euro spec is the same as Honda says in the manual...

Just took the caliper off the bike and removed the pads, they were disgusting and very smooth (glazed?)...

I sprayed the caliper out with a bunch of brake cleaner and it dripped tons of very nasting liquid, it was very dirty in there but is much better now...

I expect everything to work out really well now but I do still plan to do steel lines eventually...

[JellyDonut]

sweet bike thats a collector. Make sure to pump your breaks before riding after instalation of new break pad.. but i would defiantly agree about flushing and bleeding the breaks.. Look into purchasing a "Mighty Vac" inexpensive and great clean results for break bleeding jobs
DOT 4 will give better heat resistance

Yeah I couldnt get a real vac for the bleeding so I used a cheap one way valve... Got the job done and I would say the lever feels about like it did before I did any work (fairly solid)...

Have not had a chance to really ride so I cant say if the new pads helped.. but the old pads were very smooth and glazed so I sure hope these help...

I do plan to do steel lines next and maybe then Ill pick up a vacumm bleeder and see how I like that alternative...

The brake fluid coming out and in the master cylinder was MUCH darker then what I was putting in so I think all-in-all I may not have 100% overhauled the braking system but it is greatly improved.

[gimig]

jraice,
That doesn't look 25 days old!!!! Very sweet

Very nice, is it oil injected or pre-mix? I didn't even realize anyone was making ring dingers still in 82.

Ring dingers?

Its injected and I hope to keep it that way....

i am looking into some engine mods but havent looked into how they effect injection, hope the stock injector will still fit the needs of a more gas hungry engine...

And thanks for the compliments!

Just got word my seat, bars, spoiler and some decals shipped...

[CB750F]

The injecter just injects 2 stroke oil into the carb to mix it with the gas, or at least that's how Yamaha's and Suzuki's injection system work. Honda is probably the same or close to it. Make sure when you buy oil for in the injector tank it's made for injection systems (the oil for pre-mix (when you mix the gas and oil in the gas can) is generally thicker and won't inject right). I would go with the Honda stuff for injection systems being you have a Honda if not any injector oil should be fine. Check with a Honda dealer.

Nice find!

A ring ding is a 2 stroke single (by the way it sounds revving up and down like "Riiiiiiinnnnnnnnnnnnngggg"- when revving and "ding ding ding" when on decell. A thumper is a 4 stroke single.

Whenever I pick up oil Ill be sure to get something designed for injection...

The oil lasts forever though according to the previous owner....

When I do my engine mods I will give it a good check over (according to adjustments in the manual) because proper lubrication is even more important with new engine parts....

And as to compatibility, I was not sure if this injector put out enough oil to keep up with the larger carb and engine bore...

But I am not sure where in the line the oil is injected, could be before it reaches the carb, in which case it would still be at the proper ratio.

What is the purpose of people switching to mixed oil? I notice it mostly on performance bikes... Seems like such a hassle...

[CB750F]

What is the purpose of people switching to mixed oil?

Couple of reasons. One is to be sure the engine is getting the oil it needs. Another is to use a diferent ratio or a better performing oil.

That makes since...

Update:

Did a bit more riding just now, first time in the sunset lighting, it was a bit nerve racking but I had great visibility of other cars turning into my way (lights) which was nice... I need to make some sort of insturment gauge though because I cant see the gauge at all... No lighting system...

But Ill be doing most of my practice/riding in the daylight, I just worked an 8 hour day though and it stopped raining 2 hours ago (while I was working) so I just HAD to ride...

The new brakes feel pretty good...

Another thing that I am sure will go away but is a good thing to have right now, I find myself on any road that is windy or has bad visibilty around corners going noticably slower then the speed limit... Or right under the limit on roads usually traveled much faster... Like I said its a good thing and with time I am sure Ill get more comfortable but low speeds feel faster then they truly are...

Its a 5 speed, havent taken it into 4th more then 2-3 times and only into 5th once (wasnt necessary for my speed, could have stayed in 4th at 40-43mph but wanted to shift anyways).... So it still has a lot of capability I havent explored...

I am really enjoying this thing, supposed to rain sunday, if it doesnt or has breaks (which it has been) Ill be riding for sure...

Also next weekend I plan to take the slow route to work (35mph speed limit, vs. the fast freeway I take in the car) which is a nice 20-25 minute ride and should be pretty fun....

My starts are getting much better, went from wheelieing every time (let clutch out to fast) to having smooth stops but taking a while (taking to much time) and now I am just about at the point where I can stop, look both ways and be off....

[clockdaddy]

Excellent! It's good to hear that you're taking it slow and easy. Speed will come with practice.

# 1 rule... If you feel uncomfortable.....SLOW DOWN!!!!

CD

[CB750F]

I need to make some sort of insturment gauge though because I cant see the gauge at all... No lighting system...

The gauges aren't backlit at all?

Well I dont see any means for it and nothing happens...

Could be an electrical problem...

[clockdaddy]

I don't think any of the gauges come without backlighting in them now-a-days. I'd be having those checked real fast.

Check your fuses, check to make sure your brakelights and cruising lights are working properly !!!

CD

You said "now-a-days"... its 25 years old

Anyways Ill look into that...

The neutral light also just bit the dust two days ago but I am guessing that i mechanical, not electrical...

Also the highbeam light has never come on, but when I switch to high beams I dont notice much change...

Perhaps Ill change all the fuses though just to be safe...

Running, brake and signal lights all work fine...

Check them before every ride...

[clockdaddy]

For me, anything less than 40 years IS "now-a-days"!!!!!!!!!!!!!

LOL,
CD

Got ya

Ya I was hoping it would have something, I guess Ill have to dig into the electronics soon to fix this and the neutral light... Also my highbeam light doesnt appear to be working...
Guess it could be good news, atleast I want have to dig into the transmission to much to get the neutral light working (electric issue, not the switch).