2004 GL1800 rear brake coming on by itself

[Big Red 94]

Can anyone put a little light on a problem that has been occurring just recently were my rear brake comes on by itself forcing the bike to slow to a complete stop. The only thing that seems to get it going again is to let it cool. I have noticed that at times the rear pedal is tight and and will only depress a very small amount, its very firm. This is when i believe at this point the brake comes on. The first time it occurred the front ones came on too. I have checked pads, fluid levels for overfilling but all seems ok. I am starting to think it may lay in the brake system of being linked, but what makes it just come on.???? I check my feet are well out of the way just incase I was riding pedal, but thats not it. Honda at Nerang QLD have not heard of such a thing, but are looking into it for me. Getting kind of disturbing as its dangerous in highway situations.

[WingAdmin]

This is a well-known issue caused by a blocked return port in the brake master cylinder. Normally caused by infrequent brake fluid changes and/or pushing contaminated brake fluid up from the calipers back into the master cylinder when putting new brake pads on the bike.

Have a look through these posts: search.php?keywords=blocked+brake+retur ... mit=Search

[Big Red 94]

Thanks, i have only had the bike 12 months. I bought it second hand from original owner with 22,500kms and like new. I had fluids changed because of age (all fluids even fork) and a full service. I will talk to the guys at Honda about the return valve, other than this just happening the bike is faultless.

[Viking]

Did you have the recall performed on the secondary master cylinder problem? Or did the previous owner have it done? You may be good for a complete rear brake overhaul at Honda's cost if it has not yet been done.

[Big Red 94]

I have not, but I will be asking for it. I checked out recall notices at the time but never saw anything about rear brake. The guy I got it from hardly rode it, he found it was to big and he didnt enjoy the ride. He sold it for a Harley...???/ I had been wanting the 1800 when it first came out. This one came along and at first he was asking $23,000 and over the course of 18 months I noticed it was not selling. But his price dropped down by $5,000 and by that time I could get it. I booked it up for a complete service, small fortune..all fluids everything. Even though this bike was garaged most of its life it was old oils and fluids. For the first 12 months ( had it now for 14 months) no worries, then in early Jan this year is when the problem firsts happened. Now its done it 5 times since, today being the last time. If the brakes were old school I could sort it out, but this linked system is why I started to ask questions. A friend I work with suggested your site. I will certainly be able to work things out using it I am sure. I am going to do the Air filter myself, looks tricky but now I get about 44,000 kms its time.
Thanks for the help, I really do appreciate the reply so fast.

[Viking]

If the recall has not been done, as you think, then I would be willing to bet that your problem lies right there with the secondary master cylinder, which is mounted on the left side of the front end. Get it to a Honda dealer and they should fix you right up. Tell them about what has happened to the rear brake as well, and you may end up with a new set of rear pads at the very least, depending on how much wear and heat you experienced. Who knows, maybe a new rotor and at the very outside, maybe even a new rear caliper.

[cihilb]

Have a Honda dealer run your VIN number. They can tell you if the recall has been done. Even though it may have passed initially, there could still be a problem. There have been some instances where the SMC has passed only to show up later. The dealer might be able to double check the operation of the secondary master cylinder. It takes less than a half hour.

[Big Red 94]

Thanks, its off to Honda tomorrow for them to look at. I have been told that there is a punch mark on the bike, but will look at it when it arrives, I got stuck again on way to work today and the pedal was hard as. Would not depress until it cooled. Well will see what they come up with, but as you have put it I should get something as it maybe a design flaw. .....

[Red Ron]

You can take off the right side engine cover and on the engine block around the rear master cylinder area you should be able to see a punch mark indicating that the recall was done.

[Big Red 94]

Could not see one, so took notice and pic to show if Honda put one on while the have it. Filled up only 75 kms ago and down to half tank on the gauge (not accurate) but usually has not budged far,so there is drag on something. Pedal is hard to push down when I left it and master cylinder half full. Disc had bluish hue to it, so will be interesting what happens. Thanks, and I am glad for your help.
Great site for info.

[Red Ron]

That blueish hue don't sound good. If it is the SMC recall it shouldn't cost you anything. Best of luck to you!