82 XJ750 Maxim front brake binding when backing up

Hi All,
I am having issues with the front disc brake grabbing making it difficult to back the bike up.
It is dragging a bit with the wheel rotating forward so the wheel does not just spin freely but when you rotate it the other way it becomes difficult to move.
What would cause it to bind when backing and how would I adjust it to turn a bit more freely moving forward? I thought these would self adjust after a short amount of use but has not so far. Perhaps the piston is sticking a bit?

 

The problem is most likely in the master cylinder. There is a fluid return orifice, also known as the splooge hole. It's tiny and easily clogged. When it clogs, the brakes do not release.

I'd say, clean master cylinder (and maybe put in a rebuild kit), make sure the tiny hole is clear (sometimes you have to poke it with a guitar string or a bristle from a brush), and flush the system with fresh fluid.

 

I opened the master cylinder to check the fluid yesterday and it looked clean but of course that does not mean it is not clogged so I will take a look at it tonight. The bike appears to have been stored for a long period and has a lot of surface rust and oxidation in places but all of the fluids look clean like the bike has been in recent use. Perhaps it was used regularly but parked unprotected. In any event I will give the master cylinder a once over and see if it needs cleaning or rebuilding and put in fresh fluid.

Thanks.

 

How old are the brake lines, there is a date stamped on them. They are supposed to be replaced every 4 years. On my bike, they were the original lines. They become soft and the inside starts to break apart polluting the brake system. I would recommend rebuilding the caliber and master cylinder and replacing the brake pads and the brake lines. These bikes like to go fast, so you really need to make sure the brakes work well. Also, the pinned post on this forum refers to delamination of the rear brake shoes..a definite must read. I would imagine that your current problem is directly attributable to one or more of the above mentioned items..

 

I'd assume more that the piston is hanging up in one or both of the calipers. I have to pull mine and clean them..... Doing the same thing

 

I still have to look at the date codes on the lines. I assume them to be old due to the amount of rust at some of the connections and will have to look into replacing them. Having issues with the engine running at 3,500 rpm when it gets good and warm and the speedo reading far slower than it should. Will be tackling a lot of this during the evenings this week as time allows. Hopefully the speedo just needs a good clean and lube but I might have to remagnetize. At 45 mph she was reading 25 so it is a huge difference. Looks like I will have to pull the carbs and give them a good cleaning as well and may need to rebuild. I will reserve any purchases until I pull them apart and see as the most recent owner did do some work on the bike, just not sure how much.

Thanks for the input everyone. I will be getting her into shape, it is my fiance riding her so gotta be meticulous.

 

I'm thinking you might need a full brake rebuild...

 

I believe a .010" guitar string will fit the itty-bitty hole.

My advice, tackle one task at a time and keep asking questions here, but start a new thread for each task.

 

Read the second link in my signature. Read it thoroughly. Go over everything on the machine. There are no shortcuts to getting a 30+ year old machine in safe riding condition.

I would not start a new thread for each task. Everything is interconnected. Many symptoms can be indicators of a single problem, and many problems can have the same set of symptoms. Spreading that across several threads just makes for more opportunities for frustration.