It's not harmful, just a slightly false sense of security.
My advice to you would be to leave them alone if you don't want any headaches because the chances are REAL good that they will either round off or snap off. I've had luck in the past heating the bleeder with a propane torch and hitting it with penetrating fluid, but more times than not the old bleeders just snap off. They're not hardened so they are pretty weak when a bit of pressure is put on them. I'm a mechanic and tell you this from many years of experience. If you are serious about wanting to bleed the brakes, I highly suggest you have a full set of calipers and/or wheel cylinders on hand to replace the fubar'd ones. You can sometimes get the old bleeder out, but more times than not it's just easier to replace the damaged caliper or wheel cylinder.quote:
Originally posted by kendogg441:
Now here's a question fo you guys. On a vehicle thats never had the brake fluid flushed, espcially when you buy a used vehicle, whats the best way to get those rusted bleed screws loose? I'm thinkin some spray like PB blaster adn a torch, but, will a torch posibly melt the seals in a rear wheel cylinder in a vehicle with drum brakes?