Like what NIW said, you will get a very rough ride and most likely will NOT like it. The tires will loose the flex and you will feel every little bump.
When I worked underground they foam filled the tires on shuttle cars, all 4 of them and I will tell you they will jar your teeth out on a rough travel way. Just filling the front you will retain the flex of the rears where you sit and thats important. Liquid fill the rears and your good to go
Not to hijack this post but my manual on my L2800 suggest not filling front tires with liquid instead use weights. Do you guys agree with that and what is the down size to filling the front tires? My L2800 is 4 wheel drive with bucket.
Thanks