What to do? brakes wont let go...bikes been sitting a while

[njcafe84]

So Im starting this cafe project on a bike thats been off the road since '95 and both brakes dont really want to let go. I had to unbolt the front caliper just so the wheel would spin and the rear is dragging hard. Its very difficult to even roll the bike. My front master cylinder has been obviously leaking and is completely empty and the rear master cylinder is full with brake fluid.

Can anyone give me some insight on what to do, where to start, parts I should replace...anything will help. PLEASE HELP!

Its a 78 400e, front and rear discs

 

[jayel]

the brake pistons aren't retracting, keeping the pads squeezed to the discs... open the bleeder screws or undo the fitting to the caliper, brake systems will need to be taken apart and cleaned

 

[drewpy]

yea. you might just get away with a clean. retract the calipers using a G-clamp!

 

[OleDoc]

i have had good luck with the c clamp method.take the caliper off,take off pads and the rubber around the piston.set the clamp up on the piston and open it just a little.pump the brake and you will see a line of crud.spray it with wd 40 and brush the crud away.collapse the piston a little past the crud line and repeat process a couple of times.just make sure that you DO NOT pump the brake without the c clamp on the piston or you will have a problem

 

[XSLeo]

If Ole Doc's method gets them working then your good to go.
If they still give you trouble they will need to be torn aparts and cleaned. The groove the seal fits into in the caliper body needs special attention, any crud left in there can bind the seal and piston.
One more thing to check. Where the later one piston style caliper mounts to the bracket is a rubber sleeve that a steel sleeve slides through. This needs to slide easy, if not the brakes will bind.
Often the internal rubber parts are ok. The piston can get rusty and pitted. If the piston is pitted where it slides through the seal then it will leak and needs to be replaced.
On the M/C the same applies, often just cleaning works. It just takes a special set of snap ring pliers to get the piston out of the M/C.
Good thing is that the brakes are the same as the XS650 so Mike's XS has the rebuild kits and pistons.
Replace the lines too. The old rubber lines rot from the inside out. This lets bits of rubber plug up the caliper and M/C. New rubber lines are ok but braided stainless are much better.
Leo

 

[njcafe84]

Thank you xsLeo

Where can I order stainless brake lines from that are oem replacements?

 

[ECP89]

http://helusa.com/store/advanced_se...Csid=5820ad5716bde0189df9254fbe49ece8&x=0&y=0


I bought HEL lines for my 07 Yamaha YZ250F. Awesome quality lines!!! And you can even customize them. Planning to get a front line for my XS as it gets further along... I have no problems buying from them again. Perfect length, exceptional quality stuff.

 

[drewpy]

I used HEL lines and can recommend them

 

[XSLeo]

I think the ones Mike's sell will work on the XS400's. Just measure what you have. match the length. The ends are alloy, so you have to be careful when tightening the banjo bolts.
Most after market sellers have lines in many lengths, then use what ever ends fit your bike.
J&P, Dennis Kirk, Drag specialities, Part's Unlimited.
Shop around.
Leo