Hello,
My 1989 cheroke xj westinghouse system is broken.
When I apply the brakes, I hear air leaking.
I could not find an original new part in my area. Does anyone have any information about which vehicles the part used is similar to?

 

99-04 Grand Cherokee (WJ) is a very common swap. Get the OEM hoses to the Distribution Block, if you can...
95-96 XJ parts work as well but I suspect that'll be even harder to find. Make sure you get the spacer...
97+ XJ parts can be made to work, but not as easily as the above two options.

For all of these options, the Master Cylinder and steel lines to the Distribution Block will need changed as well to work with the new Booster.