Ok , I need a little help here. I have disc's on all four corners & a firewall mounted booster/proportioning valve. Problem is the front brakes are sticking. Bled the brakes last week and have good pedal pressure but the front brakes don't seem to be disengaging. Any ideas?
are the calipers new? sound like a sticky piston.if the calipers are old and you replaced the brake pads,did clean brake dust and dirt around the piston.I have more questions but lets start with these Bobby
Check your push rod to booster clearance, you should have a little play between the pedal and the booster otherwise your master won't completely disengage. Just pull the pin on your pedal and see if the rod comes back a little more then adjust accordingly.....Big Tim
Since it's just the front it may not be the push rod but that's sure worth checking. There's a chance the rear piston seal in the m-c clears the return port before the front one does but that's unusual. If you have any inline residual pressure valves (rpv) they should be only 2# for discs. Many master cylinders now have the rpv built into the seat the brake line tightens to. If shortening the push rod doesn't work then crack open the front line fitting when the brakes are dragging and see if the pads retract from the rotor. If they do you have something holding pressure and the rpv is a common culprit.
The front brakes engage before the rear, that's the way a master cylinder works. So if the rod is just a little to long it will cause the front brakes to stay engaged after you have pumped the pedal a few times because the master will build pressure if it is not completely disengaged causing the front brakes to lock up. Now if the rod was lets say an inch too long then the rear brakes would most likely lock up too but in this case I would say it's less than a quarter of an inch too long.....Big Tim
I don't think it's the M/C. It did the same thing last year when I had it running briefly. All components were new, including the hoses and calipers. It has sat up however for a number of years as I piddled with it. As I mentioned before I just swapped out the M/C recently. It's the same style but it came with a proportioning valve. I think the calipers have gone bad from sitting so long. Just bought a set to install but got side tracked by my dog. He got out of the yard yesterday morning and was missing all day. He came back home that evening and was is awful shape. Looks like he was attacked by a pit or two. There are huge chunks missing from all four legs with his back legs being the worst. His face is all torn up as well. Gotta play doc for awhile.
sticky To check if its the calipers or mc just crack open the pipe as it goes into the caliper, if'n it frees up the n its the mc or valve ass holding pressure.
Problem solved!! Got a chance to install the calipers and that took care of the problem. Now on to the engine. Gotta figure out why it's running so crappy!
Good on ya, Robert! Glad you got your brakes squared away! Your crappy running engine isn't a Vortec, is it? That Blazer of mine is giving the bowtie a bad rap!
No, it's not a Vortec. It's a 327 circa '68. Sometimes it idles ok but then sometimes it sounds like it's only running on half a motor, like it's starving for fuel. Fuel pump is new, changed out the filters, checked the lines for kinks but it still runs like a four cylinder. Gonna check the carb next. Actually found a new Holley 600 with electric choke on Craigslist for $150. Gonna check it out tomorrow.
