My 72 Fj40 keeps loosing brake fluid, there are no leaks, puddles, wet spots ...nothing to show where the fluid is going. The cap is on the fluid cup and is tight. Could the fluid be going into the booster ? The master cyl is new (1 yr) .
I had one of the slave cylinders on the rear drum blow a seal.. slowly lost fluid.. Due to its location I never saw a leak.. It just kind of saturated all the brake dust in the drum and slung out while moving I guess.. no wet spots or leaks.. maybe pull the rear drum off and check? Just a thought.
What haapens with my situation is: The truck sat for a week, I took it for a spin and the brakes felt really funny. I got out and checked the fluid and the rear cup was empty. I took it back home blead everything out and drove the truck for the day. When I parked it I rechecked the fluid and all was fine. The next weekend...no fluid, I repeated the bleeding and drove the truck, checked the fuild when I was done ..full just like before the following weekend the cup is empty. No signs of leaking anywhere (i'll check the rear cylinders this week). Has anyone had experience like this ?
When I had mc leaking into the booster, it ran down the firewall, and was both in and out.
It also comes to mind that somewhere, I think it was on the old SOR board that is referenced here, that a number of folks had bad experiences with CCOT M/Cs. I think one person even ended up with 4 of them before they got one that worked properly! (Don't ask me why they bought 4). You could probably do a search and find this discussion.
I just sh*t canned a new MC I bought from Cool Cruisers. The rear section never worked. Just installed a 93 fj80 MC and it works great. If your sure it's not leaking on the ground then it has to be going into the booster.