hi all, so glad i found this forum. i have a 60 model f600 with a log loader. the truck runs and drives great and i've haul several loads of logs on the old truck. i parked the truck last year and only started it a few times just to keep battery charged. i recently got it out for a drive and found i have no brakes, i figured the master cylinder was bad so i bought a rebuild kit but it didn't help so then i bought a new master cylinder and still no brakes. when i try to bleed brakes fluid will come out but it has no pressure after pumping them up, peddle goes to floor and never builds pressure in pedal or at bleeder. i suspect the booster but have no knowledge of how to start to work on it. any suggestions on where to start or what to do to get some brakes ? thanks in advance.
You have to bleed the hydrovac booster too. It's usually on the frame rail right under the driver. They can be a pain to get all the air out of sometimes. Also look at your rear wheel cylinder configuration. I have seen those with dual wheel cylinders that don't have the bleeder at the top and air can get trapped in there. I hope you don't have that system because if you do, the only way to get the air out is unbolt the backing plate and rotate it so the bleeder is positioned at the highest point, then put it all back when you get done, a real pain in the rear.
Near the bottom is the procedure that I use. The bleeder on the bottom wheel cylinder is the usual on F600s. You can eliminate the air without removing the backing plate, but it takes a helper. That procedure has always worked for me.
Also, you might want to pull the rear drums when you get a chance. I found that getting air in the system while sitting for a while is usually due to the rear wheel cylinders having a very slight leak, not really enough to notice a drop in fluid, but it lets air get into the system. If the wheel cylinder boots are damp with brake fluid, it is time for rebuild or replace.