Does anyone know how to adjust the parking brake on a 1991 680L case. It holds a little but not very good. Thanks
Check the parking brake valve - might need to change it.
parking brake won't hold Where is the valve located? Does it work off air or hydraulic? Thanks for your reply
Not 100% sure but it's going to be off hydraulic. Where it's located us beyond my knowledge....try the service manual to locate the valve.
What is a 680 L, is it abackhoe ? That is a new one on me . Last I knew it is either a 580 or 590 L . If it is just tighten the knob on the end of the handle . It is all manual , no air or hyds. involved .
Kevin, Here is a link to picture of one. Actually it is a link to a parts/ service manual. http://www.tradebit.com/filedetail.php/199400662-case-680l-ck-backhoe-loader-parts-catalog
Omcgee, It may be a worn out brake disk. The manual is here http://partstore.casece.com/us/parts-search.html#epc::mr63190ar858367
It should have a brake drum on the input drive shaft to the trans. There should be a brake chamber that is spring applied and hyd pressure released. With a helper block wheels, you will have to go under the machine and watch for the chamber rod travel, if the brake chamber rod moves while setting and releasing the parking brake, with brake released, loosen the lock nut at the yoke and remove the cotter pin along with the pin. Next turn the yoke three turns to tighten the pull to the brake shoes, install pin and cotter pin, tighten locknut. Set brakes and remove wheel blocks, move machine to a hill area, set parking brake, if machine moves repeat the adjustment again untill it will hold. Other causes of parking brake not holding, fluid leaks on the brake shoe's or worn brake shoe's/drum, haven't seen a broken chamber spring in a long time (Do not take the chamber apart without a service book, you can get hurt or killed due to the spring force inside some chambers) hope this helps some.
These pictures may help.
Thank you for the reply's. I just received my parts and service manuals. It is a drum brake and its kinda hard to picture the shoes being worn out because it has a loud buzzer if you put it in gear with brake on. Thanks again
I agree with the parking brake valve. But also check the brake pedal valve. To set the parking brake on this machine, set the rpms to at least 1200, move the pin that connects both pedals together, press and hold down both pedals for 5 seconds, then pull the parking brake valve out, release both brake pedals. The parking brake valve works off the pedal brake valve, a bad pedal valve has to be rebuilt, as CASE has zero stock on this valve. The 680L does not function the same as the 580's. Follow tinkerer's link below for parts diagram to the brake hydraulics.
I adjusted 2 times and ran out of adjustment and it still does'nt hold any better.I went thru the floor pan ,very simple. The brake drum was covered with oil and I tried washing with solvent but it didn't help.It looks like I will be pulling the drum off next if I want it fixed. Thanks again