Help with front brakes

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rand4ll

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Help with front brakes AND forks

Hello all, glad i found a forum dedicated to our XS400 :).

Anyways, my name is Randall and i have a 1980 XS400 Special. I fixed it up and it runs well and is driveable now. However i went on a nice ride today and noticed that my front brake is barely working at all. I can bear down on it and it still barely slows the bike, which leaves me with a couple of questions.

1. What do you think the problem could be?
2. Are the front brake caliper/master cylinder the same as the xs650, so that i can order the parts from mikesXS?

I am looking at getting the front caliper rebuild kit, bushing, and pads here:

http://www.mikesxs.net/products-50.html#products
Part #29-0016
Part #29-0017
Part #29-3522

I am also looking to put on all new hoses which I figure I can just measure and match them up with what I can find online. Which brings me to the master cylinder parts as well...Mine has some corrosion on the bottom of the reservoir area as well as some other areas, do yall think its best to replace the whole thing? If so, which part would i get from the link below?

http://www.mikesxs.net/products-71.html#products

If not then I would like to go with a rebuild, would Part #08-0219 and Part #08-7000 take care of all that I should need to rebuild? And looking at the price for said parts I can get the whole assembly for close to the same cost...

Anyways all your tips, suggestions, and help is very appreciated. Would love to get this stuff ordered in time to get working on it next weekend so hopefully can go on a nice ride on sunday...I do not feel safe with how the front brake is functioning right now.

Thanks all!
 
Last edited:
There can be a few reasons why your brake doesn't seem to be working right. The old rubber lines, a bit of air, oil contaminated pads from a leaky fork. I guess I would spend a little time first on examining the pads and running new brake fluid through the system. A recent thread on the XS650 covered bleeding and caliper rebuild. Its a long thread, but interesting.
http://www.xs650.com/forum/showthread.php?t=10643
 
Since there is already corrosion on the master cylinder my first guess as to why you have poor braking even when bearing down hard is a seized caliper. Second guess is air in the brake line and it needs to be bled.
 
Thanks for the replies.

So I did a bit of troubleshooting, and I can feel the caliper piston move forward a bit when i squeeze the handle real hard, so I do not think it is seized. The corrosion is right on the part under the reservoir. Also, I was able to see some tiny bubbles at one of the 'joints' in the brake line right under where the little hoop is on the lower part of the front fork, so main problem is a leaky line I think.

However, while in there, would it be a good idea to go ahead and rebuild the caliper? Or do you all think I should just start with a line only and try that? Also, I see there are the original rubber type and braided metal type as well. I am also guessing that the metal braided are better as far as both longevity as well as flexing/stretching whenever they are under pressure from the fluid, are these correct assumptions?

I am definitely replacing the lines, and I will go ahead and order the pads now, figure some new ones can't hurt, the ones I posted in first post are the right ones I hope???

Thanks again for the helpful replies!
 
do it all in one go, caliper seal kit and a good clean out of the Master cyl.

you'll have fun bleeding a dry brake circuit, but in the end its safety that counts!
 
X2

If you don't do it all now you will just be going back to do what you ignored the first time around. It will be cheaper, quicker, and safer in the long run.
 
Well, I went ahead and ordered all the parts except the brakeline, they were sold out of the 41" stainless one.

Does anyone have a good place to get a stainless brake line w/ the fittings on it? If not, are the fittings easy to put onto a line, as i saw some links for those but can't find a full line...

Thanks for any links
 
I emailed cyclebrakes sales to see if he can supply me with a line, hopefully so. I saw the lines on ebay as well, but I am in Texas and it would take a long time to come from the UK to here unfortunately, they are also quite expensive (~$70 in US dollars).

As for getting verification if they are the right parts, no I did not, I have ordered many other parts from there that work, and am just hoping on all these. If not I will just have to return them. Though I do not think that will be the case, they all look the same as the parts on my bike.

Thanks again!
 
Cyclebrakes wont be cheap either.. but you'll get a custom line with nice fittings, swivel ends, the exact bends you want in the bangos, and the exact length you want. They are nice lines. You just have to figure out what to tell them you need.
 
Looks like it said $60. I will see what they say, hopefully some other suggestions will come in as well.

Thanks
 
I measure what I want and save an ebay watch list. so long as the banjos are the right angle and the length is correct any pipe will do.

got mine for £10, new
 
I will just build an earls performance line through summit racing with these parts:

1 EAR-63010140ERL - Brake Line, Speed-Flex, Braided Stainless Steel, 40 in., -3 AN Female, -3 AN Female, Each
$16.95

1 EAR-9978031ERL - Fitting, Brake Adapter, Large Round Banjo, 3/8 in.-10mm, Steel, Straight, Each
$12.95

1 EAR-9978034ERL - Fitting, Brake Adapter, Large Round Banjo, -3 AN -10mm, Steel, 30 Degree, Each
$14.95

The russels brand fittings were a bit cheaper but also looked it quality wise, so i sprung the extra for the earls...

Anyways, thanks for all the help
 
Alright, some good news and some bad. First, all the right hand controls and the master cylinder are wired up and working correctly. The connector on the right hand controls (kill switch/starter button) was NOT the same one in my bike. It has 4 wires instead of 3, and different colors. I figured the black was a ground that my original did not have, and after closer inspection confirmed that and also that the brown and red wires on the new controls connected to the red and red on the original wiring, and blue to blue for the start button. Just cut both connectors off and wired it up with some connectors of my own I had. And i went ahead and hooked up the ground as well to one already in the headlight housing...

For the bad news, the pads I ordered are NOT the right part for the xs400. I should have taken it apart first and compared the pictures, lesson learned, going to keep searching for some. Also, as usual in taking the bike apart, I found more work that needs to be done, the pads were coated in oil, when feeling on/into the bottom of the fork on that side i can feel sticky oil everywhere...so looks like next weekend i will be rebuilding my forks before finishing up the brakes :)

Now I know a few of you have done this before and can help me insure i get all the right parts this time. Going to start doing some thread searches and part hunting to see what I can find on here and what I need to order for replacement.

Thanks
 
drewpy said:
well, you need to post a picture of those pads so we know which ones you have!
Click to expand...

HAHA, i found the right pads right here:
http://www.partsnmore.com/parts/yamaha/xs400/?filters[category]=chassis
part #29-3523

So I am set there, also found these fork seals:
http://www.partsnmore.com/parts/yamaha/xs400/
part #27-1011

Now i just need the right dust seals, however i don't think these are the right ones:
part #27-1049

Also looking for the brake caliper piston, mine actually has some marks on the outer piston portion and i would like to replace it as well...and it was a pain to remove because the seals were all coated in some nasty stuff and almost sealed to the piston...luckily already got the new seal kit...
 
So does anyone know where to get the right dust seals and maybe even a caliper piston for my model? I am still not having any luck. I have the 33mm stanchion tubes, i have found 35mm dust caps (guessing the measurment is internal diameter), but not the right ones for my forks, have found the fork seals however...

Any help would be great, would love to actually ride this weekend :p
 
Well, finally found the dust seals, too bad they are $20 each! But with no other leads that they are the right ones or not, guess I am going with these here:

http://www.bikebandit.com/houseofmotorcycles/1980-yamaha-xs400sg/o/m8261#sch222086
#17

Damn...50 bucks with shipping, thats a hard hit...got the pads and seals ordered from partsNmore, now hunting for that darned brake caliper piston...

Hopefully this parts hunt of mine may help someone else, since nobody knows where to find some of this stuff...its like a treasure hunt almost, except the treasure you end up with is a lighter wallet :doh:

EDIT: If it possibly helps anyone to help me, the measurements on the caliper piston are

Diameter: 43mm
Height: 33mm

Thanks
 

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