CurtisTheGreat

Greetings all!

I'm very new (AKA only about 30 hours on the bike, total) to motorcycles, and my first bike is a 1987 Honda Rebel 450.

At the end of this last summer, I had a few issues come up with the bike, that I'm just now getting around to fixing. But I'm a bit stumped on this one, so hopefully someone can help me.

Please remember, I'm very new to all this, so I may ask some pretty stupid questions or call things by the wrong names. I'll do my best here! :P


Basically my issue is that I cannot get the front brake to actually engage. Originally, the brake actually locked up, very tight, and I couldn't get the front wheel to move at all. The brake lever was almost solid tight... I couldn't depress it at all.

I took apart the entire brake system and was able to get the two pistons behind the brake pads to finally release and move back away from the pads, so I could remove the entire brake assembly.

I drained all the fluid from the line in the process... I didn't think it would be an issue, as I could bleed the line and move forward... but that's where I'm hitting a snag. I can't get any fluid to move through the tube at all. Upon inspecting the system, I found that the reservoir was full of some kind of rust colored "mud". I can only assume it has never been changed at all. After cleaning it all out, I removed the spring assembly from the reservoir housing, to make sure it was clean as well. The rubber seals all seem to be in good condition, and I cleaned out the entire housing and put it all back together. I know there are no clogs in the housing area at all.

The problem (and perhaps I just need to go about this differently) is that when it is all back together, but with no brake line attached, I depress the brake level and no fluid comes out of the reservoir at all.

I assumed I may need to attach the brake line and re-hook up the entire brake system and see if I could get pressure... but I get nothing. I pump the brake lever like crazy, but I never get any resistance at all.


I'm sure there is something I am doing wrong, and I hope that is all it is. I don't want to have to order parts if I can avoid it. Does anyone have any tips that can help me get my front brakes working?

Thanks a bunch for the help!

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flitecontrol

Could be a couple of things. I've never squeezed the lever with the brake line disconnected from the master cylinder reservoir, but would think fluid should come out. Since it had a lot of crud in it, I would take it apart again and ensure every opening is clear. Might help if you could used compressed air to clear the openings. Just be sure to wear eye protection and that all the seals have been removed. You don't want to blow a critical O ring into the far corner of the garage!

Did you have the cover on the reservoir when you squeezed the handle? If not, put it on and see if there is any change.

Did you blow down the disconnected, drained brake line to be sure there isn't something blocking it?

The lack of pressure usually means there is air in the line somewhere. Try bleeding the line again, adding fluid to the reservoir periodically so air can't get in the line. When done, fill the reservoir to the full mark. If you don't have pressure, make sure there isn't a leak somewhere. If you have some pressure, but not a normal amount, pull the lever all the way in and use a rope or string to tie it in that position. Leave it overningt, remove the string and pump the lever several times in the morning. If this improves the pressure, repeat until it is normal. Be sure to check the reservoir and refill as needed because this is supposed to force bubbles in the system out.

Good luck.

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I'm keepin' all the left over parts. I'm gonna use 'em to build another bike!

2001 Rebel 250, 1989 Vulcan 750
Putting your bike info in your signature helps others help you!

Guba

I once had a truck that had a bad brake line. It had the opposite problem. I could get fluid to the brake cylinder to stop, but it didn't want to release. Or if it did release, the brake pad would touch the disc and get enough friction to make the brake expand and grip even tighter. It seems that the inside of the brake line had peeled away somewhere and acted as a check valve letting fluid go in one direction only. Could be whats going on with your brake line.

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Some days beer tastes good...other days beer tastes better!

'07 Rebel 250 26,000 miles

CurtisTheGreat

Thanks for the tips. I work tomorrow, so Wed is the first day I'll have to try these things. I'll let you all know.

Thanks again!

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cagie

Something else to look at that I didn't see in your OP. Did you check/clean the calipers? You mentioned 'rust colored mud'. I would be checking the pistons for corrosion/scarring. Then flush the whole thing out with fresh fluid or denatured alcohol, clean again, then reassemble. Make sure you compress the pads completely into the caliper housing before putting back on and bleeding.

Clymers says, "if [any] part is less than perfect, replace it". I tend to agree when talking about the front brakes.

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Comments contained in my posts are not intended to cause physical or psychological stress and are mearly my two cents worth, and in this economy, that's cheap!
87 CMX250C 'the Pygmy Pony'
87 CMX450C 'Black Lithium'

jax

I have rebuilt a lot of 450 front brakes. Almost everyone I have gotten the front brake is stuck. They really don't like to sit any at all.
After everything is apart you need to clean the outside of the pistons with steel wool to get all the rust off and I flush the caliper with brake fluid and blow out all the small passageways with compressed air. Be sure the "o" rings in the caliper are in good shape and not ripped or frayed. The pistons will fit tight when you put them back in, be careful when you put them in to get them straight or you might shave the "o" ring. I put a block of 3/4" wood across the inside of the caliper with the pistons installed in the caliper and use compressed air to move them back and forth to make sure they move freely.
As for the brake line use compressed air to clean it out and run brake fluid through it to make sure the fluid goes through it.
The brake reservoir needs to be taken apart and cleaned fully. Wipe all the crud out of the reservoir and run brake fluid through it until it is clean. There is a little metal washer type of thing in the bottom of reservoir over the hole. Be sure to take that out and clean the hole with compressed air and reinstall the metal part over the hole.
I have a vacuum brake bleeder I hook up to the bleeder hole in the caliper to suck the brake fluid down from the reservoir.
For some reason I have found that after all is cleaned and fresh fluid put in the reservoir the brake will not sometimes pump up.
Good luck

Ride safe

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JunkyardDog

First of all, the front brake is SERIOUS. Do not ride the bike if the brake is not working properly. I really don't have anything to add that has not already been said, I have also run into a number of bikes with hydraulic brake problems. The most common cause is corrosion and seal deterioration from sitting for long periods of time. Moisture can also get into the system and wreak havoc. Your only real choice is to disassemble EVERYTHING, clean everything, sand off any corrosion with very fine sandpaper, or better yet, a sanding sponge. You can get them at Walmart. This includes the piston, inside the caliper bore, the plunger, and inside the master cylinder bore, clean all the metal parts with brake parts cleaner, and replace ALL rubber and plastic parts. If you cannot remove all corrosion and pitting by sanding, the part will have to be replaced. You might be able to make it work, but it will leak. The hose may or may not be reusable. If it has any noticeable cracks in it, replace it. You don't want it to fail and leave you with no brakes in a critical situation. Most manufacturers recommend replacing brake hoses every 2 years, but IMO that is ridiculous, unless you let the bike sit outside. But, if you let a bike sit outside around here, there won't be enough of it left to put new brake hoses on in 2 years. I still have the original brake hoses on my 8 year old Vulcan 750, bought new and taken care of, and have no plans to change them anytime soon. I do however replace the fluid every 2 years or so. Every single part of the brake system should be in perfect condition, and the system should be functioning perfectly. Your life literally depends on it.
If after getting it working, If you notice ANY problems with it, stop riding the bike until you get them straightened out. I normally don't recommend this, but if you have any doubts about your ability to work on the brake system, take it to a shop. Unlike riding without a helmet, where you are taking a chance, a brake failure WILL cause an accident. It's a sure thing. Jerry.

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CurtisTheGreat

Thanks for all the replies! I got the brakes working without problem, thanks to you all!

I wanted to post a follow up of what I did.

I went ahead and cleaned out all the parts of the entire brake system. I made sure everything was clean and in good condition.

Then, I hooked up the entire system, filled the reservoir with DOT4 brake fluid (the cover said 3 or 4 works, so I assumed I was ok with the 4) and then I used a brake line bleeding pump to actually pull fluid through the line, and I instantly had pressure.

Now, the brakes work fine and I don't have any issue at all. I think that was my initial problem. I had way too much air in the line to even be able to start pushing fluid from the reservoir.

Thanks again for everyone's help! I very much appreciate it!

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JunkyardDog

Glad you got it going. I still would not trust the brake completely till you ride it a few days, and check carefully for leaks. If it still works fine, you should be ok. A vacuum pump is the ONLY way to bleed brakes. The old method of having someone pump the brake pedal (in a car), while you opened and closed the bleeder screw and kept the master cylinder full was a real PITA.

We have an expensive setup at work, but I have found the MityVac is the best thing for the home mechanic. Jerry.

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CurtisTheGreat

Ya, that's exactly what I was doing before... pump and have someone open and close the bleeder screw. That wasn't working... at all. haha

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