Can't get brakes to fit

So I am replacing the front brake pads for the first time (Just bought the bike recently, this is the last thing that needs to be done) and for some reason I cannot get the pads to fit in the caliper. The piston is compressed all the way but the only way for the brake pads to fit is if I remove the large bolt holding the whole caliper on, and if I keep the caliper attached I can only fit one brake pad on.

I have a 1982 XJ650J Maxim

 

Did you rebuild the caliper?
Did you get the correct brake pads? The Maxim ones are made with an angle built in to account for the caliper pivoting. The correct ones look like wedges.

 

Thanks k-moe, Yes. I got the correct ones but the angles seem off. The caliper with the pads fit nicely until I try to bolt on the caliper to the fork, then nothing fits. Its very strange. The caliper has been rebuilt, was the original one on the bike and the pads are canted and fit nicely in the caliper, it is just when we put it all together nothing lines up.

 

I had to do some minor grinding on the pads with a dremel to get the slide pin to go all the way through both pads and fit correctly....

 

there is something about this in the catalog brakes section xj4ever



NOTE: we recommend that you "chamfer" the edges of all brake pads and shoes before installation, as this modification tends to help prevent brake squeal and noise. "Chamfer" merely means to file a very small 45-degree angle on the very outside edges of the friction material. Our HCP9785 disc brake pad dampening fluid is also very effective at eliminating such noise, as is the HCP10736 brake assembly grease----and to be honest, we recommend the use of all possible methods, as brake squeal is really annoying!

650 maxim brakes
HCP20762 Aftermarket semi-metallic front DISC BRAKE PADS SET, enough to do one front caliper. Semi-metallic material features the original central "wear-limit" groove. Fits all XJ650 Maxim and Midnight Maxim models, all 1979-81 XS1100 Special left front caliper, and 1980 XS1100LH Midnight Special left front caliper. NOTE: these brake pads are supposed to be "wedge-shaped"; it's because of the unique "rear pivot point" design that is used on this style caliper. Most other bikes have a true "floating" caliper, that floats perpendicular (towards-and-away from the rotor), rather than one that pivots at its back end. Each set:

 

It is beyond simply applying a 45 degree chamfer to the edges. The fit is so tight that you physically cannot insert the pads, and even if you were able to use tools to force them in the pressure they would be putting on the rotor would be equivalent to having the front brake constantly being applied. There must be something not connected properly because this is not adding up

 

Where did you source the pads from?
Some sources claim to sell pads that fit an 82 XJ Maxim but really they aren't the right ones.
How thick is the rotor?

Is the piston retracted fully in the rebuilt caliper housing? It is a relatively snug fit with new pads but should not be difficult.

A recently purchased bike may reveal that the previous owner had their way with it and 'stock' components have been replaced. Pictures may be very helpful for the smart guys here to decipher and troubleshoot this problem.

 

Good morning. Not sure if this will be of any help but just in case....

Is it possible your pads have a thick coat of paint on the edges making them wider than they really should be? I replaced pads in my XJ900 project and I found a thick coat of paint on the metal backing plate...especially the edges. Although the pads fit, they were tight and would have bound had I installed them with the paint in place. I ended up using a file to clean the paint off and then the pads installed and they could move on the pins without binding/wedging against the inside of the caliper.

Hope that helps!

 

It's going to be a few days before I can get back to my bike to take pictures. I know the brand on the brakes is BikeMaster, and they look exactly as shown in the Haynes manual I have. They don't appear to have thick paint on them. They are so tight that I can only fit about 5 millimeters of the pad into the caliper before it physically cannot be pushed in any farther.

 

Good morning PizHelp. Please keep in mind...I have not worked on a 650 Maxim for some time so I may be way off base here with this assessment. However, based on what you are describing, I think the issue falls into one of two possibilities;

If the pad is tight, side to side, and binding inside the caliper....I would look to see if there is any paint or coating on the outside edges of the pads and remove what is there.

If the pads are tight, face to face, making it difficult to install both and/or slide it over the rotor....I would look to confirm the caliper pistons are fully pushed into the caliper housing.

Hope that helps and I am sure you will get this sorted soon.